Technical Report: Comparison of National Application Documents for Eurocode 3: Part 1.1 and Eurocode 4: Part 1.1

P255: Comparison of National Application Documents for Eurocode 3: Part 1.1 and Eurocode 4: Part 1.1 Discuss me ... TEC...

Author: J.J.C. McFarland | J. C. Taylor | Steel Construction Institute (Great Britain)

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P255: Comparison of National Application Documents for Eurocode 3: Part 1.1 and Eurocode 4: Part 1.1 Discuss me ...

TECHNICAL REPORT SCI PUBLICATION P255

Comparison of National Application

Created on 30 March 2011 This material is copyright - all rights reserved. Use of this document is subject to the terms and conditions of the Steelbiz Licence Agreement

Documents for Eurocode 3: Part 1.1 and Eurocode 4: Part 1.1

J J C McFarland BEng MSc DIC J C Taylor MA CEng MICE FIStructE

Published by: The Steel Construction Institute Silwood Park Ascot Berkshire SL5 7QN Tel: 01344 623345 Fax: 01344 622944


SCI Technical Reports Technical Reports are intended for the dissemination of research results as and when they become available and/or as ‘specialist documents’ for further discussion. They provide an opportunity for interested members to comment and offer constructive criticism.


Please forward your comments to Charles King, The Steel Construction Institute, Silwood Park, Ascot, Berkshire SL5 7QN. Email: [email protected]

© 2001 The Steel Construction Institute Apart from any fair dealing for the purposes of research or private study or criticism or review, as permitted under the Copyright Designs and Patents Act, 1988, this publication may not be reproduced, stored or transmitted, in any form or by any means, without the prior permission in writing of the publishers, or in the case of reprographic reproduction only in accordance with the terms of the licences issued by the UK Copyright Licensing Agency, or in accordance with the terms of licences issued by the appropriate Reproduction Rights Organisation outside the UK. Enquiries concerning reproduction outside the terms stated here should be sent to the publishers, The Steel Construction Institute, at the address given on the title page. Although care has been taken to ensure, to the best of our knowledge, that all data and information contained herein are accurate to the extent that they relate to either matters of fact or accepted practice or matters of opinion at the time of publication, The Steel Construction Institute, the authors and the reviewers assume no responsibility for any errors in or misinterpretations of such data and/or information or any loss or damage arising from or related to their use. Publications supplied to the Members of the Institute at a discount are not for resale by them. Publication Number:

SCI P255

ISBN 1 85942 090 7 British Library Cataloguing-in-Publication Data. A catalogue record for this book is available from the British Library.

ii


FOREWORD The European Prestandards ENV 1993–1–1 (Eurocode 3: Design of steel structures: Part 1.1 – General rules and rules for buildings) and ENV 1994–1–1 (Eurocode 4: Design of composite steel and concrete structures: Part 1.1 – General rules and rules for buildings) were issued by the European Committee for Standardisation (CEN) in 1992. This was done to enable designers to become familiar with all the Structural Eurocodes during their ENV (BSI Draft for Development) period, prior to achieving EN (European Standard) status. The ENV Eurocodes are intended to be used in conjunction with National Application Documents (NADs) valid in the country where the building or civil engineering project is located. Currently the national variations detailed in the NADs militate against easy use of the Eurocodes. This publication will interest potential exporters and designers of structures in other countries, as well as benefiting those concerned with the further development of the Eurocodes.


The publication provides a comprehensive review of those Clauses of Eurocode 3: Part 1.1 and Eurocode 4: Part 1.1 that have been modified by the respective NADs of the various European countries. National Application Documents have been produced by most of the member countries of CEN, the European standards organisation. These NADs have made a number of adaptations to the Clauses of Eurocodes 3 and 4 (EC3 and EC4). This Technical Report goes through each Clause affected, to report the existence of modified national provisions. The NADs also provide an accompaniment to the general comments already made by the CEN member countries in relation to the conversion of EC3 from ENV to EN status. This work was partially funded by the Construction, Innovation and Research Management Division of the Department of the Environment, Transport and the Regions.

Do not use this document as a valid reference for any values or statements of validity. Always refer to the actual document if designing to suit a particular country’s NAD.

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P255: Comparison of National Application Documents for Eurocode 3: Part 1.1 and Eurocode 4: Part 1.1

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CONTENTS

Page No.

SUMMARY 1

INTRODUCTION 1.1 Background information 1.2 This publication 1.3 Format of National Applications Documents

1 1 1 2

2

CURRENT STATE OF ISSUE OF NATIONAL APPLICATION DOCUMENTS 2.1 Eurocode 3: Part 1.1 2.2 Eurocode 4: Part 1.1

6 6 7

3


vii

4

EUROCODE 3 3.1 Boxed values 3.2 Clauses in ENV 1993–1–1 references by National Application Documents 3.3 Comparison of National Application Document requirements EUROCODE 4 4.1 Boxed values 4.2 Clauses in ENV 1994–1–1 referenced by National Application Documents 4.3 Comparison of National Application Document requirements

v

8 8 8 25 95 95 96 96



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SUMMARY This Technical Report presents a review of the various National Application Documents for Eurocode 3: Part 1.1 and Eurocode 4: Part 1.1 relating to steel and composite construction respectively.


The National Application Documents are produced separately by each country to facilitate the use of the Eurocodes on a trial basis. This report compares, on a clause by clause basis, the requirements such as partial factors, member design, connection details etc. Simple tabular summaries, indicating which Clauses have been modified by each country, are also presented.

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1

INTRODUCTION

1.1

Background information

1.1.1 The Structural Eurocodes European Prestandards ENV 1993–1–1 Eurocode 3: Design of steel structures: Part 1.1 – General rules and rules for buildings and ENV 1994–1–1 Eurocode 4: Design of composite steel and concrete structures: Part 1.1 – General rules and rules for buildings are two of the Structural Eurocodes resulting from the former programme of work sponsored by the Commission of the European Communities and the General Secretariat of EFTA to make available a common set of rules for the design of building and civil engineering works. They are issued by the European Committee for Standardisation (CEN), and are intended for use in association with a National Application Document (NAD), issued under the authority of the national government of each country.

1.1.2 National Application Documents Created on 30 March 2011 This material is copyright - all rights reserved. Use of this document is subject to the terms and conditions of the Steelbiz Licence Agreement

The purpose of the NADs is: C

to assign definitive values to safety elements for which only indicative values are given in the ENV (the so-called ‘boxed values’)

C

in the absence of harmonised supporting standards, to reference compatible national standards

C

to provide national guidance on the application of the Prestandard.

The NAD also specifies the loading to be used for buildings to be constructed in the country concerned, pending the availability of harmonised European loading in Eurocode 1. It also includes additional recommendations to enable the ENV Eurocode to be used for the design of buildings to be constructed in that country.

1.1.3 Boxed values In all the Structural Eurocodes, certain safety-related numerical values such as partial factors are only indicative, and the values to be used in practice have been left to be fixed by the national authorities in each country. Such safety-related numerical values are indicated in the Eurocodes by enclosing them in a box, and are thus generally referred to as ‘boxed values’. The NAD gives the actual national values, selected to reflect national loading codes and local requirements concerning practice and public safety.

1.2

This publication

1.2.1 Purpose The purpose of this publication is to collate information regarding the state of issue of the NADs, and to compare their technical content, so as to assist those involved in designing structures in one country that are intended for construction in another country.

1


1.2.2 Layout The first part of this document includes tables that indicate those Clauses for which further national guidance has been given, i.e. information other than national values for partial factors, which are covered separately in Tables 1a and 1b. Some NADs reference paragraphs, others reference only the Clause number. In Table 2 reference is made only to the Clause number. The rest of the document is structured in the same order of Clauses as Eurocode 3: Part 1.1, with the adaptations made by the NADs quoted under the relevant Clause numbers.

1.2.3 Use of this document Do not use this document as a valid reference for any values or statements of validity. Always refer to the actual document if designing to suit a particular country’s NAD.

1.3

Format of National Application Documents


1.3.1 General Each country has its own style of presenting its NAD. Most countries follow a common format but some countries’ NADs have their own unique format. Note: Continental European practice is to use a comma to denote decimals, instead of the decimal point used in the UK, and to use a full stop to denote thousands, instead of the comma used in the UK. This continental practice is used in the Eurocodes, which is very confusing for UK engineers. For example, in the Eurocodes: 2.678 = two thousand, six hundred and seventy-eight 2,678 = two point six seven eight (in UK terms).

1.3.2 Eurocode 3 The NADs of Denmark, Finland, Germany, Italy, Sweden and Switzerland all follow a similar format. The structure of these NADs matches the Clause order in Eurocode 3 (EC3). At every modified Clause, all these NADs give the paragraph number to which the change applies, along with a brief description of the adaptation, together with a reference to the relevant National Code, if applicable. The NADs of Belgium and the Netherlands were not available in English, however they also follow the format noted above. The NADs of France, Ireland, Portugal and the United Kingdom all deviate somewhat from the common format. Their particular style of presentation is outlined below. France The French NAD (or DAN) is comprehensive and is set out very clearly. The DAN introduces three types of national adaptation: comments, amendments and 2


invalidations. A comment explains or makes a Clause clearer by means of remarks or examples. An amendment proposes an alternative, completes an imprecise Clause or specifies more precisely the field of application of a Clause, or the range of validity of a formula or procedure. An invalidation cancels a Clause considered inappropriate, unsafe or not applicable. Where necessary, the DAN also replaces invalidated Clauses, formulae or procedures with new ones. As this report is intended only to deal with comparison of the various NADs, in the case of the French DAN only the amendments and invalidations are considered for comparison purposes. Ireland The Irish NAD is short and concise, providing only the minimum additional information required. Chapter 1 explains some aspects of EC3, relating to combination factors, building categories and loading values. Chapter 3 simply lists the reference documents to be used in the absence of those listed in EC3, without any explanatory comments. Portugal


The Portuguese NAD is also brief. It covers key considerations such as steel notation, slenderness of compression members and lateral stability of beams. United Kingdom The UK NAD uses its own Chapter headings, the main concerns of this comparison being contained in Chapter 6 Additional recommendations.

1.3.3 Eurocode 4 Nine NADs were available at the beginning of August 1998, for use in Austria, Denmark, Finland, France, Germany, Ireland, Switzerland, the United Kingdom and the Czech Republic. Two further NADs were available in draft form for use in the Netherlands and Spain. Copies of all of these documents are available from the appropriate National Standards bodies. English language versions of the nine published NADs and the draft NAD for the Netherlands are available for inspection in the library of The Steel Construction Institute. Austria The text comprises only brief guidance on other standards to be used in conjunction with the ENV, values of partial factors and a table of characteristic strengths. Czech Republic Attention is drawn to the use of a high value, 1,15, for the partial factors on structural steel but the low load factors used for unfavourable permanent and variable actions (1,20 and 1,40 respectively). No technical changes (other than to ‘boxed values’) are made. Additional remarks of the NAD provides commentary on the ENV.

3

Section 5


Denmark The NAD is mostly concerned with specifying partial factors for materials. Loads, load factors and combination factors are to be taken from the Danish Standards DS409 and DS410. This leads to a change in the format of the rules given in Clause 2.3.2.2 of the ENV. The materials factors are also significantly different from the ‘boxed values’ of the ENV. Reduced values of elastic moduli are used in buckling calculations. Deviation can be made from the Principles of the ENV, if the soundness of this can be justified. Finland The document provides information on the basis of design, including partial factors, supporting standards, and additional rules where the ENV is considered to be insufficient. Some of the additional remarks are explanatory.


France France has provided a single document that comprises the French translation (denoted EC4) of the CEN-approved version of the ENV, and the national changes (denoted DAN 1.1) that constitute the NAD. Some Clauses of Eurocode 4 (EC4) have been declared invalid and are printed against a shaded background. The remaining Clauses of EC4 and the NAD together form the French experimental standard for national application, denoted EC4–DAN 1.1. Clauses declared invalid are replaced by NAD Clauses denoted by I. The NAD also provides two other types of Clause: those denoted by A, which amend EC4 Clauses, and those denoted by C, which provide commentary on EC4 Clauses. The titles of the French supporting standards are listed and the status of each Standard is indicated Germany The contents of the NAD are mainly references to national standards but they also include a small but significant number of technical changes. Few comments are given, but an annex gives a brief explanation of the terms used in EC4 concerning resistance of frames to lateral forces. Ireland The document is intended to provide the minimum additional information required to permit application of ENV 1994–1–1, and therefore concentrates on values for actions, and supporting standards. The Netherlands The text of the NAD includes a small number of additional requirements, in addition to the references to Dutch standards necessary at the ENV stage. These safety classes to be used to determine (F are defined in the relevant Dutch Standard. The ‘boxed values’ of the ENV are to be used, unless they are specifically changed in the NAD.

4


Spain A draft of the NAD is available in Spanish. No English translation is available. There is no Spanish national code for composite building structures and there are no probability-based national codes. If Eurocode 1 had ENV status, this document along with ENV 1994–1–1 could have been used together in Spain with only a short NAD for other reference standards. However, at this time the national loading code NBE–AE–88 has to be used as the basis for the actions. The values in that document have been considered to be characteristic values but have been adapted by the NAD to give the same safety level as would result from the use of Eurocode 1 with EC4. The ‘boxed values’ in ENV 1994–1–1 have not been changed. Switzerland The NAD comprises a Basic Document that explains the purpose of NADs and gives an overview of the Eurocode programme, followed by supplementary parts for each Eurocode.


United Kingdom Tables in the NAD give detailed information on the partial factors, loading codes and other reference standards to be used. The main technical changes are given in Section 6 Additional recommendations of the NAD. No formal distinction is made between informative and normative requirements in Section 6, but a number of the recommendations are of the former kind; they result from textual examination of the ENV. Design rules to provide structural integrity are given in Annex A of the NAD. These are based on BS 5950–1:1990.

5


2 CURRENT STATE OF ISSUE OF NATIONAL APPLICATION DOCUMENTS 2.1

Eurocode 3: Part 1.1


As far as the authors are aware, the state of issue of NADs in the various countries at the beginning of August 1998 was as follows: Austria (A)

No NAD will be issued

Belgium (B)

NAD available in French

Czech Republic (CZ)

NAD published in 1994, English version available

Denmark (DK)

NAD issued September 1993, English version available

Finland (SF)

NAD published October 1994 with English translation

France (F)

NAD published April 1995 with English translation

Germany (D)

NAD published November 1993 with English translation

Greece (GR)

NAD available in Greek only

Iceland (IS)

No NAD will be issued, ENV issued in English

Ireland (IRL)

NAD published

Italy (I)

NAD published May 1993, English translation available

Luxembourg (L)

No standards issued

Netherlands (NL)

NAD published August 1995, available only in Dutch

Norway (N)

NAD in preparation

Portugal (P)

NAD published February 1998 in Portuguese

Spain (E)

NAD in preparation

Sweden (S)

NAD published June 1995 with English translation

Switzerland (CH)

NAD issued July 1994, English version available

United Kingdom (UK)

NAD published in November 1992

Note: The letters used above after the names of countries are conventionally used in European meetings and are generally similar to those used to identify the country of registration of motor vehicles. These letters are used for identification throughout this publication, including the summary tables.

6


2.2

Eurocode 4: Part 1.1


As far as the authors are aware, the state of issue of NADs in the various countries at the beginning of January 1995 was as follows. No information about any further developments is available: Austria (A)

NAD published 1994

Belgium (B)

Work was due to start in 1995

Czech Republic (CZ)

NAD published 1993

Denmark (DK)

NAD published August 1994

Finland (SF)

NAD published December 1994

France (F)

NAD published April 1994, included within French language text of the ENV

Germany (D)

NAD published February 1994

Greece (GR)

Draft NAD was expected March 1995

Iceland (IS)

A NAD is not expected to be produced

Ireland (IRL)

NAD published 1993

Italy (I)

NAD in preparation

Luxembourg (L)

NAD in preparation

Netherlands (NL)

Draft for comment published November 1993

Norway (N)

NAD in preparation

Portugal (P)

NAD in preparation

Spain (E)

Draft available in Spanish

Sweden (S)

NAD expected to be published January 1995

Switzerland (CH)

NAD published March 1994

United Kingdom (UK)

NAD published May 1994

Note: The letters used above after the names of countries are conventionally used in European meetings and are generally similar to those used to identify the country of registration of motor vehicles. These letters are used for identification throughout this publication, including the summary tables.

7


3

EUROCODE 3

3.1

Boxed values

3.1.1 Partial factors (F for actions Partial factors for actions (F are summarised in Table 3.1. The values are generally the same as the indicative values given in ENV 1993–1–1. A notable exception is Denmark, which uses smaller (F values but larger (M values. The UK distinguishes between favourable and unfavourable effects of permanent actions in accidental design situations.

3.1.2 Combination factors Ri


No ‘boxed values’ for these factors are stipulated in ENV 1993–1–1. Reference is instead made to ENV 1991-1 or national loading codes. Considerable variation in the values, and in the form of presentation, occurs among the NADs. For this reason, no comparison tables are presented for Ri values. Reference should therefore be made to the NADs themselves. The values chosen appear to have been influenced in some cases by the national loadings to be used and existing national values for partial factors. In other cases they appear to have been influenced by the values in different drafts of ENV 1991–1 available at their date of issue. ENV 1993–1–1 Clauses 2.3.3.1(5) and 2.3.4(5) provide simplified rules for combinations of actions on building structures. These avoid use of Ri factors, however their use is ruled out in the Portuguese NAD.

3.1.3 Partial factors (M for resistances Partial factors for resistances (M are summarised in Table 3.2. The values assigned by the different countries for partial factors (M for resistances vary greatly.

3.2

Clauses in ENV 1993–1–1 referenced by National Applications Documents

The Clauses of ENV 1993–1–1 referenced by the NADs are shown in Table 3.3. The details of the references are given in Section 3.3.

8

Table 3.1

Partial factors (F for actions in NADs for EC3

Reference in EC3

Action

Symbol

EC3

Partial factors (F specified in NAD A

B

DK

SF

F

D

GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

CZ

2.3.2.2(3) Permanent (GA

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

0,90 or 1,05

1,00

Favourable

(G.inf

1,00

1,00

1,00

1,00

1,00

1,00

1,00

0,9

1,00

1,00

1,00

Unfavourable

(G.sup

1,35

1,35

1,35

1,35

1,35

1,35

1,40

1,20 or 1,35

1,35

1,35

1,20

Favourable

(Q.inf

0,00

0,00

0,00

0,00

0,00

0,00

0,00

0,00

0,00

0,00

0,00

Unfavourable

(Q.sup

1,50

1,50

1,50

1,50

1,50

1,50

1,50

1,20 to 1,50

1,50

1,50

1,40

(QA

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

Favourable

(G.inf

1,10

0,90

1,10

1,10

1,10

1,10

1,00*

1,10

1,10

1,10

1,10

Unfavourable

(G.sup

1,35

1,00

1,35

1,35

1,35

1,35

1,40

1,35

1,35

1,35

1,20

Both parts

(G.inf

1,00

1,00

1,00

1,00

1,00

1,00

1,10*

1,00

1,00

1,00

1,00

(Ff

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

Accidental situation

2.3.3.1(1) Permanent

9

Variable

2.3.3.1(2) Variable Accidental situation 2.3.3.1(3) Permanent (2 parts)

9.3.2

Fatigue

*The Italian NAD is not clear. It is also possible that these values are intended to be the same as the ‘boxed values’ in EC3, that is 1,10 and 1,00 respectively.


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Table 3.2 Reference in EC3 5.1.1(2)

10

6.1.1(2)

6.5.8.1

Partial factors (M for resistances in NADs for EC3 Resistance

Symbol

EC3 DK

SF

F

D

IRL

I

S

CH

UK

CZ

Class 1, 2 or 3 cross sections

(M0

1,10

1,28

1,10

F1

1,10

1,10

1,05

1,00

1,10

1,05ãn S1

1,10

1,05

1,15

Class 4 cross sections

(M1

1,10

1,28

1,10

1,10

1,10

1,10

1,05

1,00

1,10

1,05ãn

1,10

1,05

1,15

Buckling of member

(M1

1,10

1,28

1,10

1,10

1,10

1,10

1,05

1,00

1,10

1,05ãn

1,10

1,05

1,15

Net section at bolt holes

(M2

1,25

1,56

1,25

1,25

1,25

1,25

1,20

1,25

1,25

1,20ãn

1,25

1,20

1,30

Bolted connections

(Mb

1,25

1,56

1,25

F2

1,25

1,25

1,35

1,25

1,25

1,20ãn

1,25

1,35

1,45

Riveted connections

(Mr

1,25

1,56

1,25

1,25

1,25

1,25

1,35

1,25

1,25

1,20ãn

1,25

1,35

1,45

Pin connections

(Mp

1,25

1,56

1,25

1,25

1,25

1,25

1,35

1,00

1,25

1,20ãn

1,25

1,35

1,45

Welded connections

(Mw

1,25

1,56

1,25

F3

1,25

1,25

1,35 I1

1,25

1,25

1,20ãn

1,25

1,35

1,50

A

B

GR

IS

L

NL

N

P

E

Slip resistance Ultimate – general

F1 F2 F3 I1 S1

Partial factors (M specified in NAD

1,25

1,56

1,25

1,10

1,25

1,25

1,25

1,25

1,25

1,10(n

1,25

1,20

1,30

Oversize holes and along long slots

(Ms,ult

1,40

1,72

1,40

1,25

1,40

1,40

1,50

1,40

1,40

1,10(n

1,40

1,35

1,50

Serviceability

(Ms,ser

1,10

1,10

1,10

1,20

1,10

1,10

1,25

1,10

1,10

1,00

1,10

1,35

1,30

If the steel used has the mark ‘NF Acier’ then (M0 = 1,0, otherwise (M0 = 1,1. If the bolt is in tension then (Mb = 1,5, otherwise (Mb = 1,25. (Mw = 1,25 if steel Fe 360, (Mw = 1,30 if steel Fe 430 or Fe E275; (Mw = 1,35 if steel Fe 510 or Fe E355. For Class I welds, (Mw = 1,05; for Class II welds, (Mw = 1,20. (n is according to BKR 94, 2:115.


Discuss me ...


Table 3.2 continued Reference in EC3 9.3.4(4)

Action

Partial factors (M for resistances in NADs for EC3 Symbol

EC3

Partial factors (M specified in NAD A

B

DK

SF

F

D

GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

CZ

Fatigue (Mf

1,00

1,56

1,00 SF1

1,00

1,00

1,00

1,00

1,00

1,00

1,00(n

CH1

1,00

1,00

Poor accessibility, ‘fail-safe’

(Mf

1,15

1,56

1,15 SF1

1,10

1,15

1,25

1,15

1,15

1,15

1,10(n

CH1

1,00

1,10

Accessible, ‘non fail-safe’

(Mf

1,25

1,56

1,25 SF1

1,20

1,25

1,25

1,25

1,25

1,25

1,00(n

CH1

1,00

1,15

Poor accessibility, ‘non fail-safe’

(Mf

1,35

1,56

1,60 SF2

1,25

1,35

1,35

1,35

1,35

1,35

1,00(n

CH1

1,00

1,20

K.1(8)

Joint in hollow section lattice girder

(Mj

1,10

1,28

1,10

F4

1,10

1,10

1,10

1,10

1,10

1,00(n

1,10

1,05

C.2.5

Brittle fracture ‘Non-critical’

(c

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00(n

1,00

1,00

‘Critical’

(c

1,50

2,24

1,50

1,50

1,00

1,50

1,50

1,50

1,50

1,00(n

1,50

UK1

11

Accessible, ‘fail-safe’

SF1 SF2 F4 CH1 UK1

Not for use in buildings. For buildings 1,35 should be used if periodic inspections of the structure are carried out according to a separate plan. In this case a method shall be presented in the plan that should be applied when the structure has reached its service life. The value of 1,6 should be used if no periodic inspections are carried out. The whole of Annex K is invalidated and replaced in the French NAD. Not applicable, no partial factors given. SIA 161 should be used. For Fe 430 or Fe E275 (c = 1,2; for Fe 510 or Fe E355 (c = 1, ; for all other grades (c = 1,5.


Discuss me ...


Table 3.3

EC3 Clauses modified by NADs Reference in EC3 Clause Number and Title

A

B

DK

12

0.5.3

Concept of reference standards

0.5.4

Weldable structural steel

1.1.1

Scope of EC3

1.1.2

Scope of Part 1.1 of EC3

1.1.3

Further parts of EC3

1.2

Distinction between principles and application rules

X

1.3

Assumptions

X

2

Basis of design

X

2.1

Fundamental requirements

2.2.2

Actions

2.2.3

Material properties

2.2.5

Load arrangements and load cases

2.3.2

Ultimate limit states

2.3.3

Partial factors for ultimate limit states

2.3.4

Serviceability limit states

SF

F

D

GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

CZ

X X

X X

X

X

X X

X

X

X X X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X X

X

Note: X denotes that a Clause has been modified by the NAD.

X

X

X

X

X

X

X

X

X

X

X


Discuss me ...


Table 3.3 continued

EC3 Clauses modified by NADs

Reference in EC3 Clause Number and Title

13

2.4

Durability

2.5

Fire resistance

3.1

Materials; General

3.2

Structural steel

3.2.1

Scope

3.2.2

Material properties for hot rolled steel

3.2.3

Material properties for cold formed steel

3.2.4

Dimensions, mass and tolerances

3.3.1

Connecting devices general

3.3.2

Bolts, nuts and washers

3.3.3

Other type of preloaded fasteners

3.3.4

Rivets

3.3.5

Welding consumables

4.1

Serviceability; Basis

4.2.1

Deflections; Requirements

4.2.2

Limiting values

A

B

DK

SF

F

D

GR

IS

IRL

I

L

NL

X X X

X

E

S

CH

UK

CZ

X

X

X

X

X

X

X

X X

P

X

X

X

N

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X X X

X

X

X

X

X

X

X

X X X

X

X X


X

X

X

X

X

X

X X

X


Discuss me ...


Table 3.3 continued



A

B

DK

SF

F

X

X

14

4.2.2

Limiting values

4.2.3

Ponding

4.3.1

Dynamic effects; Requirements

X

4.3.2

Structures open to the public

X

4.3.3

Wind-excited oscillations

X

5

Ultimate limit states

5.1.1

General

D

GR

IS

IRL

I

L

NL

N

P

E

S

X

CH

UK

CZ

X

X X X X X X

X

X

X

X

X

Table 5.2.1 Design assumptions

X X

5.1.2

Frame design

X

5.1.5

Beams

5.1.6

Members with combined axial force and moment

X

5.1.8

Fatigue

X

5.2

Calculation of internal forces and moments

X

5.2.1

Global analysis

5.2.2 5.2.3

X

X

X

X

X

X

Design assumptions

X

X

X

Structural systems

X

X

X


X

X X X

X

X


Discuss me ...


Table 3.3 continued



A

B

15

5.2.4

Imperfections

X

5.2.5

Sway stability

X

5.2.6

Frame stability

X

5.2.7

Column requirements for plastic analysis

X

5.3.2

Classifications

X

5.3.4

Cross-section requirements when elastic global analysis is used

X

5.3.5

Effective cross-section properties of Class 4 cross sections

X

5.3.6

Effects of transverse forces on webs

5.4.2

Section properties

5.4.3

Tension

5.4.4

Compression

X

5.4.5

Bending moment

X

5.4.6

Shear

X

5.4.7

Bending and shear

X

DK

SF

X

F

D

X

X

X

X

X

X

GR

IS

IRL

I

L

NL

N

P

E

S

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X


X X X

X

X X

CH

UK

CZ


Discuss me ...


Table 3.3 continued



A

B

DK

SF

F

16

5.4.8

Bending and axial force

X

5.4.9

Bending, shear and axial force

X

X

5.4.10

Transverse forces on webs

X

X

5.5

Buckling resistance of members

5.5.1

Compression members

X

X

5.5.2

Lateral-torsional buckling of beams

X

X

5.5.3

Bending and axial tension

5.5.4

Bending and axial compression

5.6.1

Shear buckling resistance; Basis

5.6.2

Design methods

5.6.4

Tension field methods

5.6.7

Interaction between shear force, bending moment and axial force

5.7

Resistance of webs to transverse forces

5.7.2

Length of stiff bearing forces

5.7.6

Transverse stiffeners

D

GR

IS

IRL

I

L

NL

N

P

E

S

X

CH

UK X

X X

X

X

X

X

X X

X

X

X

X

X

X X

X

X X

X

X

X

X X X


X

X

X

X X

X X X

X

X

CZ


Discuss me ...


Table 3.3 continued



A

B

DK

SF

F

17

5.8

Triangulated structures

5.8.1

Triangulated structures; General

5.9

Built-up compression members

X

5.9.1

Basis

X

5.9.2

Laced compression members

X

5.9.3

Battened compression members

X

5.9.4

Closely spaced built-up members

X

5.9.5

Star-battened angle members

X

6.1.1

Connections subject to static loading; Introduction

6.1.2

Applied forces and moments

X

6.1.3

Resistance of connections

X

6.1.4

Design assumptions

X

6.1.5

Fabrication and erection

6.2

Intersections

X

6.3

Joints loaded in shear subject to vibration and/or load reversal

X

D

GR

IS

IRL

I

L

NL

N

P

E

S X

X

X

X

X

X

X

X

X

X

X


X X

X

CH

UK

CZ


Discuss me ...


Table 3.3 continued



A

B

DK

SF

F

18

6.4.1

General

X

6.4.2

Classifications by rigidity

X

X

6.4.3

Classification by strength

X

X

6.5

Connections made with bolts, rivets or pins

6.5.1

Positioning of holes for bolts and rivets

X

6.5.2

Deductions for fastener holes

X

6.5.3

Categories of bolted connections

X

6.5.4

Distribution of forces between fasteners

X

X

6.5.5

Design resistance of bolts

X

X

6.5.6

Design resistance of rivets

X

6.5.7

Countersunk bolts and rivets

6.5.8

High strength bolts in slip-resistant connections

X

6.5.10

Long joints

X

6.5.12

Fasteners through packings

6.5.13

Pin connections

D

GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

X X

X

X X

X X

X

X X

X

X

X

X

X X


X

X

X

X

X

X X

X

X

X

X

CZ


Discuss me ...


Table 3.3 continued



A

B

19

6.6

Welded connections

6.6.1

General

X

6.6.2

Geometry and dimensions

X

6.6.3

Lamellar tearing

6.6.4

Distribution of forces

X

6.6.5

Design resistance of a fillet weld

X

6.6.6

Design resistance of butt welds

6.6.7

Design resistance of plug welds

6.6.8

Joints to unstiffened flanges

6.6.9

Long joints

X

6.7

Hybrid connections

X

6.8.1

General

X

6.8.2

Splices in compression members

X

6.8.3

Splices in tension members

X

DK

SF

F

D

GR

IS

IRL

I

L

NL

X

X

X

X

P

E

S

CH

UK

X

X

X

X

X

X

X

X X

X

N

X

X

X

X

X

X

X

X X X


X

X

X

CZ


Discuss me ...


Table 3.3 continued



A

B

6.9

Beam-to-column connections

6.9.1

Basis

X

6.9.2

Moment-rotation characteristic

X

6.9.3

Moment resistance

X

DK

SF

F

X

X

Figure 6.9.2 Derivation of approximate moment-rotation characteristics

X

20

Figure 6.9.4 Moment-rotation characteristic with an initial hinge rotation Figure 6.9.5 Rotational stiffness Sj

D

X X

X

X

Figure 6.9.6 Variation of rotational stiffness with applied moment

X X

Figure 6.9.7 Rotation capacity NCd

X

X

6.9.4

Rotational stiffness

X

X

6.9.5

Rotation capacity

6.9.6

Classification of beam-to-column connections

X

X

X

6.9.7

Calculated properties

X

X

X

6.9.8

Application rules

X

X


X

X

GR

IS

IRL

I

L

NL

N

P

E

S X

CH

UK

CZ


Discuss me ...


Table 3.3 continued



A

B

DK

SF

F

D

21

6.10

Hollow section lattice girder joints

6.11.1

Base plates

6.11.2

Holding down bolts

6.11.3

Application rules

X

7


X

7.1.1

Scope

7.1.2

Requirements

7.2

GR

IS

IRL

L

NL

X

N

P

E

S

CH

X

X X

X

X X

X

Project specification

X

X

7.3

Fabrication restrictions

X

X

7.5.1

Holes

7.5.2

Clearance in holes for fasteners

X

7.5.3

Bolts

X

7.5.6

Tightening of bolts

7.5.7

Slip resistance contact surfaces


I

X

X X

X X

X

X

X X

X

X

X

UK

CZ


Discuss me ...


Table 3.3 continued



A

B

DK

SF

F

22

7.6

Welded connections

7.7.4

Fabrication tolerances

7.8

Inspection and testing

8

Design assisted by testing

8.1

Basis

8.2

Planning of tests

8.4

Test evaluation

8.5

Documentation

9

Fatigue

9.1.2

Scope

9.1.3

Limitations

X

9.1.4

Necessity for fatigue assessment

X

9.1.5

Definitions

9.2

Fatigue loading


D

GR

IS

IRL

X X

X

I

L

NL

N

P

E

S

CH

UK

X X

X

X X

X

X X X

X

X

X X

X

X X

X X

X

CZ


Discuss me ...


Table 3.3 continued



A

B

23

9.3.1

Partial factors; General

9.3.2

Partial factors for fatigue loading

9.3.4

Recommended values for (Mf

X

9.5.2

Fatigue assessment based on nominal stress ranges

X

9.6.1

General

X

9.6.3

Fatigue strength curves for non-classified details

X

9.8

Classification tables

DK

SF

X

F

D

GR

IS

IRL

I

L

NL

N

P

E

S

X

X

X

X

X

X

X

X

X X

X

X

X X

X X

Table 9.8.6 Hollow girder joints

X

Annexes General Comments

X

Annex B

Reference standard

X

X

X

X

Annex C

Design against brittle fracture

X

X

X

X

Annex E

Buckling length of the compression member

X

X

Annex F

Lateral-torsional buckling

Annex J

Beam-to-column connections

X

UK

CZ X

Table 9.8.5 Welded joints with load-carrying welds


CH

X

X

X

X

X


Discuss me ...


Table 3.3 continued



A

B

DK

SF X

F

D

24

Annex K

Hollow section lattice girder connections

X

Annex L

Design of column bases

X

Annex M

Alternative method for fillet welds

X

Annex Y

Guidelines for loading tests

X

Y.1

General

X

Y.3

General test procedures

Y4.1

Specific test procedures; Acceptance test

Y4.2

Strength test

X

Y4.3

Test to failure

X

Y4.5

Testing to determine strength functions and model factors


X

GR

IS

IRL

I

L

NL

N

P

E

S

X

X

X

X

X

X X

X X

X

X X

X

X

CH

UK

X

CZ


Discuss me ...



3.3

Comparison of National Application Document requirements

The details of the NAD requirements are listed below in order of ENV 1993–1–1 Section numbers, with the letter symbol for the relevant country as listed in Section 2. In most cases the text given is that in the relevant NAD (or in an English translation of the NAD). Text from the NADs is sometimes only quoted in part, omitting introductory phrases etc., and in other cases unclear English has been clarified. In a few instances, comments have been made by the authors. Text following a paragraph number, e.g. “(3) A value is given for ...”, is generally additional to the text of ENV 1993–1–1, except where noted otherwise. No distinction is usually made between principles and application rules.


FOREWORD 0.5

Matters specific to this Prestandard

0.5.3

Concept of reference standards

D

The German standards are listed in Annex A of the German NAD.

0.5.4

Weldable structural steel

D SF

For Fe510, the chemical composition of the cast shall be checked with the requirements of DIN EN 10025. (3) The highest admissible carbon equivalent values based on cast analysis shall be agreed at the time of ordering, according to the Standard SFS–EN–10025.

0.5.5

Partial factors for resistances

SF

(5) The partial factor (M0 equals 1,1 in this NAD.

1

INTRODUCTION

1.1

Scope

1.1.1

Scope of Eurocode 3

D

(4) ENV 1998 Eurocode 8 is not yet available, so DIN 4149 Part 1 and DIN 4149 Part 1A apply. (5) ENV 1991 Eurocode 1 is not yet available, so DIN 1055 series of standards applies. No document equivalent to Eurocode 8. Add to (1): ENV 1994–1–1 together with the accessory NAD may be assumed to equal NEN 6700: 1991.

IRL NL 1.1.2

Scope of Part 1.1 of EC3

DK

ENV 1993–1–1:1992 is not valid for structures that can be assigned to high safety class in accordance with DS 409 paragraph 1.2.6. 25



Discuss me ...

SF

(4) Annexes D, K and Z are not covered by this NAD. Annex D was accepted as an ENV in June 1993; Annex K was replaced by a new annex in June 1993. (5) Annexes G, H, N and S are not covered by this NAD.

1.1.3

Further Parts of EC3

NL SF

Include after (3) the list of relevant reference standards given in this NAD. This NAD does not cover the further Parts 1.2, 1.3 and 2–8. In addition, it does not cover the Parts that are being prepared and referenced in Part 1.1 of the Prestandard SFS–ENV–1993–1–1:1992.

1.2

Distinction between principles and application rules

D

DK

A distinction is made in the declarative value of the rules as follows: – principles, in the form of obligations, prohibitions and basic principles – application rules, in the form of recommendations and authorisations under concrete conditions – explanations, in the form of examples, references, sketches and figures. Deviation from the principles can be made, if justified.

1.3

Assumptions

D DK NL

‘Boxed values’ are specified in DIN V ENV 1993–1–1. ‘Boxed values’ are included in DS/ENV 1993–1–1 NAD:1993. ‘Boxed values’ are specified in NVN–ENV 1993–1–1.

2

BASIS OF DESIGN

CH DK

(2) is replaced by the NAD SIA 460.010. Instead of Chapter 2, DS 409, Chapters 4 and 5 and DS 410 should be used. This Chapter gives general requirements, which are not material dependent. In our opinion this belongs to the ‘Basis of Design’ described in Eurocode 1. The Prestandard SFS–ENV 1991, in conjunction with the accompanying NAD, shall be applied instead of Chapter 2 of the Prestandard SFS–ENV–1993–1–1.

NL SF

2.1


IRL

The requirements of Clause 2.1(2) can be met by Clause 2.4.5 of BS 5950–1. Add as (5) the text of 5.2 and 5.3 from NEN 6700: 1991. For road bridges and pedestrian and cycle bridges, safety classes in accordance with BRO94, 10.6 are to be applied. For railway bridges BV BRO, 110.6 is to be applied. Design rules to provide structural integrity by limiting the effects of accidental damage are given in Annex A of the NAD.

NL S UK

26


2.2

Definition and classifications

2.2.2

Actions

2.2.2.1 Definitions and principal classification 2.2.2.2 Characteristic values of actions CZ D

F


NL S

Instead of Eurocode 1, the characteristic (representative) values of actions are given in CSN 73 0035. Characteristic values of loads are the ones marked as ‘normative’ values in CSN. The values in the DIN application standards apply as the characteristic values of actions. The following is specified with regard to DIN 1055 Part 4, August 1986 edition: – The last sentence of 3.3 shall not be applied; the note to 3.3 remains valid – Clause 4 shall not be applied – Clause 5 of DIN 1055 Part 5, June 1975 edition shall not be applied. (4) Until the publication of ENV 1991 Eurocode 1, the characteristic values of ordinary variable actions to be used with this experimental standard are given in the NAD. Replace (1) and (5) with: (1) The characteristic value of action must be taken from values in Chapters 7, 8 and 9 of NEN 6702: 1991. (1) The second line shall be replaced by Eurocode 1 or BKR 94, 3, or for road bridges and pedestrian and cycle bridges BRO 9, 2, or for railway bridges BV BRO, 202. (2) The characteristic value of a permanent load shall be assumed to be the value that has a probability of 50% of not being exceeded. (4) The characteristic value Qk of a variable load shall be assumed to be the value that has a probability of 98% of not being exceeded some time during one year.

2.2.2.3 Representative values of variable actions B CZ

D F

The values for the combination factors (R0, R1 and R2) used with this experimental standard are given in the NAD of Eurocode 1 of ENV 1991–1–1. The Table in the NAD shows these values. The values of combination factors should be those given in Table 2.2. At the same time: – snow drifts are considered as accidental actions – imposed loads of floors in buildings are considered as a single load but should be reduced according to Clause 80 of CSN 73 0035. In case the temperature is needed to consider in calculation or in procedure of construction of steel structure, it is possible to suppose the average temperature of indoor structure between –10 and +30°C. The real temperatures are dependent on placement, type and purpose of structure. (4) Table R1 is applicable to assess the relevant combination factors (Ri). (4) The values of the factors Ri to be used are given in a Table in the NAD. 27


IRL NL S

UK

Values found in BS 6399–1 with amendment slip No. 1: AMD 4949 and BS CP3 Chapter V Loading, Part 2: Wind loads with amendment slips No. 1: AMD 4952, No. 2: AMD 5152 and No. 3: AMD 5343. Add to Clause 2: The factor Ri (i = 0, 1 or 2) must be equal to R, taken from Chapters 8 and 9 in NEN 6702: 1991. R0 and R1 shall be replaced by R in BKR 94, 2:21. For road bridges and pedestrian and cycle bridges, values of a load factor R( for different loads and load combinations are given in Table 22–1 in BRO 94 and for railway bridges in Table 2.2.2–1 in BV BRO. In the UK the average temperature of internal steelwork varies from –5 to +35EC. The actual range, however, depends on the location, type and purpose of the structure.


2.2.2.4 Design values of actions S

(2) The second relation shall be replaced by Qd = (GQK or 1,0 RQK. (1) (2) and (3) For bridges see 2.2.2.3.

2.2.3

Material properties

2.2.3.1 Characteristic values S

The characteristic value shall normally be put equal to the fifth percentile for the strength characteristics of a material and the mean value for its deformation characteristics [Basis of Design, Clause 5, Material Properties, (5)].

2.2.3.2 Design values D S

Design values of the resistance side Rd, determined by tests, require the approval of the chief building inspectorate authorities. (1) Equation 2.3 shall be replaced by BKR 94, 2:322. (3) Shall be replaced by KR 94, 8:33.

2.2.5

Load arrangements and loadcases

IRL

To be replaced by BS 6399–1 with amendment slip No. 1: AMD 4949 and BS CP3 Chapter V Loading, Part 2: Wind loads with amendment slips No. 1: AMD 4952, No. 2: AMD 5152 and No. 3: AMD 5343.

2.3

Design requirements

2.3.2

Ultimate limit state

2.3.2.1 Verification conditions S

(3) For bridges the limit state theory is accepted only for calculation of accidental loads. (5) Shall be replaced by BKR 94, 7:3122.

28


2.3.2.2 Combinations of actions CZ D

IRL NL


S

UK

The combination factor for accidental action A is 0.5. For the verification of static equilibrium the permanent load with stabilising effect is multiplied by 0.9. Factors Ri of Table R1 apply. (2) For the partial factors, the values of 2.3.3.1 apply. If verification is in accordance with expression 2.9, the combination factors R0 in Table R1 are to be used. For assessing structural strength in accordance with expression 2.10, the combination factors of columns 3 and 4 of Table R1 are to used in conjunction with (GA = 1,0. Use factors from BS 6399–1 with amendment slip No. 1: AMD 4949 and BS CP3 Chapter V Loading, Part 2: Wind loads with amendment slips No. 1: AMD 4952, No. 2: AMD 5152 and No. 3: AMD 5343. Add to Clause (2): For fundamental combinations the value of the variable loading Qk:1 may be multiplied with Rt, taking into account the Classes 5.1 and 5.2 from NEN 6702: 1991. (1) and (2) Table 2.1, equations 2.7(a) and 2.7(b) shall be replaced by BKR 94, 2:321 Table a and b. (3) Shall be replaced by BKR 94 2:321, Table b. (4) The reference to equations 2.9 and 2.10 is deleted. (1), (2), (3) and (4) For bridges see 2.2.2.3. Accidental design situation, values of R1, R2 and AK, in Table 2.1 of EC3: Part 1.1, should be determined from Annex A of the NAD.

2.3.2.3 Design values of permanent actions S

(1) and (2) Shall be replaced by BKR 94, 2:321, Table a. (1), (2) and (3) For bridges see 2.2.2.3.

2.3.2.4 Verification of static equilibrium D

The rules of DIN 18 800 Part 1 shall also be noted with regard to the verification of site safety.

2.3.3

Partial factors for ultimate limit state

2.3.3.1 Partial factors for actions on building structures B

CZ D

Table 1 of this NAD gives the values of the partial factors for actions, (F . It must be noted that the values in the Belgian standard correspond with the ‘normal’ safety level and this same standard also gives the values to be considered for the ‘reduced’ and ‘increased’ safety levels. ENV 1991–1–1 (Annex 2) also allows the change to different levels of safety (reliability index $). (4) Reduction factor Rvec should be 0.7. (4) ‘Vectorial effect’ means, for example, joint effect of longitudinal force and bending moment. (5) Load cases H and HZ are applicable approximately to the following conditions: – load case H corresponds to condition 2.11 – load case HZ corresponds to condition 2.12. 29


IRL

NL S

(1) Factors to be taken from BS 6399–1 with amendment AMD 4949 and BS CP3 Chapter V Loading, Part 2: Wind amendment slips No. 1: AMD 4952, No. 2: AMD No. 3: AMD 5343. Replace Table 2.2 by the Table given in the NAD, which three classes for the combinations of factors (G and (Q. In (4) the value for Rvec should be taken as 1,0. (1), (2) and (3) shall be replaced by BKR 94, 2:321.

slip No.1: loads with 5152 and introduces


2.3.3.2 Partial factors for resistances B

Table 2 of the NAD gives the values of the partial factors (F for resistances.

2.3.4


NL

Add to Clause 2: – For fundamental combinations the value of the variable loading Qk:1 may be multiplied by Rt, taking into account Classes 5.1 and 5.2 from NEN 6702: 1991. – In frequent combinations, the values Qk for creep calculations may be multiplied by Rk = 0,6. – Quasi-permanent combinations are made equal to frequent combination. (2) Equations 2.14 and 2.15 shall be replaced by BKR 94, 2:321 Table C. Equation 2.16 shall be replaced by BKR 94, 2:21. For bridges see 2.2.2.3.

S

2.4

Durability

I

After paragraph 2 of EC3, insert the following paragraph 3: (3) Precise precautions must be taken to avoid the effects of corrosion. In the absence of specific measures, the precautions specified in point 6.1.1 Minimum thicknesses in Part Two of Ministerial Decree 14 Feb 1992. Normally at least 50 years’ service life is presupposed for buildings. For overhead travelling cranes, however, normally 20 years’ service life applies. The ‘service life’ concept is defined in BKR 94, 2:13.

S

2.5

Fire resistance

CZ

Calculations of fire resistance should follow ENV 1993–1–2 draft. The following alternative Czech standards are available: – CSN 73 0802 Fire protection of buildings. Common regulations – CSN 73 0804 Fire protection of buildings. Industrial buildings – CSN 73 0821 Fire protection of buildings. Fire resistance of civil engineering structures. The standards of the DIN 4102 series are applicable. In the absence of ENV 1993–1–2, reference should be made to the local fire authority. Fire protection should be designed in accordance with BKR 94, 10. The factors (n, (M0 and (M1 are to be put equal to 1,0 and (M2, (Mp, (Mb, (Mr and (Mw are to be put equal to 1,20 in the event of fire.

D IRL S

30


UK

Pending the issue of ENV 1993–1–2 (Eurocode 3: Part 1.2), BS 5950–8:1990 should be used.

3

MATERIALS

3.1

General

IRL SF

(2) Standards in BS 5950 may be used in the absence of Reference Standards 1–4 and 6–10 in Annex B. The characteristic values given in this Chapter can be used in design when the temperature is greater than !40EC but less than +100EC, unless otherwise indicated.

3.2

Structural steel

D

Certificates shall be provided in accordance with DIN 50 049 for the products used. The given material data apply for structures with a service temperature within the range !40 to 100EC. Grade A steels are not covered in EC3: Part 1.1. They are not included in the harmonised text of EN 10025 and appear only in Annex D of BS EN 10025:1990.

S


UK

3.2.1

Scope

D

SF

(3) Annex D is being prepared, the steels of DIBt and DASt Ri 011 ‘High strength weldable fine grain structural steels StE 460 and StE 690, application for steel structures’ are applicable. Standards referred to in BS 5950 may be used in the absence of Reference Standard 1. The things mentioned under (3) are cancelled. Standards SS–EN 10 025+A1 and SS–EN 10 113 Appendix B shall be applied in accordance with NAD(S)/SS–EN 10 025 and SS–EN 10 113, Edition 1. In addition to the steels mentioned in Annex B, the SS–steels mentioned in the Table under 3.2.2.1 may also be used. This NAD does not cover Annex D.

3.2.2

Material properties for hot rolled steel

IRL NL S

3.2.2.1 Nominal values B

D

Paragraphs 1 to 4 as well as Table 3.1 are replaced by: (1) The nominal values of yield stress and ultimate resistance fu of hot rolled steel are given in the standard EN 10025 and its amendment EN 10025/pr A1 for grades of steel S235, S275 and S355 and in EN 10113–1, !2 and !3 for steel grades S275 and S355. Table R2 in this NAD decodes the designations of EN 10 027 Part 1 and the material numbers given in EN 10 027 Part 2. When calculating the Hertzian limiting pressure in steel bearings, DIN V ENV 1993–1–1 does not give any characteristic values. It is recommended that values in Table R3 contained in this NAD are used. They are determined by conversion from DIN 18 800 Part 1.

31


DK F

I IRL

NL S


SF

It should be noted that the strength properties shown in Table 3.1 for Fe 360, Fe 430 and Fe 510 deviate from Table V.3.1.1 in DS 412 and Table 4 in DS/EN 10025. Paragraphs 1 to 4 and Table 3.1 are to be deleted because the thickness ranges are not in conformity with EN 10025 and EN 10113. In order to avoid contests, reference standards in Annex B should be referred to, as concerns the nominal values of yield strength fy and ultimate tensile strength fu. At point 3.2.1(1) and point 3.2.2.1 of EC3, replace the entire content with paragraphs 2.0, 2.1, 2.2 and 2.3 of Part Two of Ministerial Decree 14 Feb 1992. (1) and (3) Standards referred to in BS 5950 or EN 10025 shall be used instead of the absent documents EN 10025 and prEN 10113. (5) There is no equivalent document in Ireland to deal with high strength steel in Annex D. Replace (1) with: The nominal values must be determined in accordance to Table 2 and Table 3 of NEN 6770: 1991. The things mentioned under (3) and (5) are cancelled. (1) is replaced by Table 3.1 in this NAD. The use of slow rusting steel in bridges is not permissible. This NAD does not cover Annex D.

3.2.2.3 Fracture toughness B

D

DK

F

I

IRL NL

Add to point 1: The lowest service temperature shall be taken as 0°C for internal structural elements and –20°C for structural elements in the open air. Add to point 2: Attention is drawn to the fact that the fabrication of hot finished hollow sections (cold formed but hot finished) can cause reduced toughness in welded construction. (3) Reference to Annex D. (4) Reference to Annex C. The steel grades may be selected according to application and weldability in accordance with DASt Ri 009. (1) The lowest temperature should be determined as specified in DS 412, paragraph 3.2.2. The upper part of Table 3.2 should be replaced by the Table given in A(2) of the NAD. (1) Recommended values of lowest service temperature should be given or reference standards in Annex B should be referred to. (3) For high strength steels with grades and qualities according to EN 10113 serial standards, the design method of Annex C should be referred to. In relation to Table 3.2 of EC 3, greater thicknesses can be used only when the fracture toughness has been verified as prescribed in point 3.2.2.3. Table 3.2 of EC 3 refers to structural elements with low stress level and not of primary importance (conditions S1, S2, R1 and C2). For other cases, refer to Annex C. For structural members under severe conditions, refer to S3 service conditions. (3) There is no equivalent document to Annex D, High Strength Steel, available in Ireland. (4) Annex C may be used. Replace this paragraph by 5.2.4 of NEN 6770: 1991. 32


S

UK

3.2.3

Material properties for cold formed steel

D

NL

Part 1–3 is in preparation, so, for determining the material properties of cold formed elements, 2.1 and 3.6 of DASt Ri 016 apply. (1) Impairment of the material toughness due to cold forming should be taken into account. (1) BS 5950–5 shall be used in the period that ENV 1993–1–3 is in preparation. A(1) in the NAD describes how this impairment should be compensated. The things mentioned under (1) are cancelled.

3.2.4


IRL

(1) Standards referred to in BS 5950 should be used in the absence of Annex B Reference Standard 2. (1) The values of the cross-sectional properties of all rolled steel sections, plates and structural hollow sections should not be more than 6% less than those calculated on the basis of the nominal dimensions. The designer shall case by case take into account greater deviations allowed in the product standards for profiles.

DK IRL


(4) BSK 94, 7.21 can be used. For road bridges and pedestrian and cycle bridges, the required ductility class shall be determined in accordance with BRO 94, 54.13. For railway bridges, the flanges and web in main beams, transverse beams and longitudinal beams shall be not less than Ductility Class D, and flanges in tension, of greater than 50 mm thickness, shall be not less than Ductility Class E. The maximum thickness should not exceed the value given in Table 15 of the NAD. For crane girders under normal use, the loading rate to be used in calculations for brittle fracture should be taken as R1.

SF

3.3

Connecting devices

3.3.1

General

IRL

(2) Standards referred to in BS 5950–2 should be used in the absence of normative Annex B.

3.3.2

Bolts, nuts and washers

D

For bolts of grade 8.8 and 10.9 and nuts of grade 8 and 10, the manufacturing works shall provide continuous proof that the mechanical properties, surface condition, dimensions and tightening behaviour requirements are met. This proof shall be provided by means of a works certificate as specified in DIN 50049. Bolts of different grades and rivets shall be tested in accordance with DIN ISO 898 Part 1 and Part 2. If galvanized bolts are used, only completed sets (bolts, nuts and washers) from one manufacturer shall be used.

33


3.3.2.1 General D

F

(3) Only bolt grades 4.6, 5.6, 8.8 and 10.9 are permitted. The list of the relevant dimensional and tolerance standards is given in Table R4 of this NAD, for bolt connections with non-preloaded bolts, and in Table R5 for bolt connections with preloaded bolts. (3) Bolt Grade 6.6 is added to Table 3.3 with the following strength values: Bolt grade

6.6

fyb (N/mm )

360

fub (N/mm )

600

2

2

IRL NL


S

(1) Standards referred to in BS 5950–2 should be used in the absence of normative Annex B. The things mentioned under (2) are cancelled. Replace (3) with: The nominal values must be determined in accordance to Table 4 of NEN 6770: 1991. (1) Bolts, nuts and washers according to BSK 94, 7:142 and 7:143 can be used as an alternative.

3.3.2.2 Preloaded bolts D IRL S

High strength bolts can only belong to grade 8.8 at least. (1) Standards referred to in BS 5950–2 should be used in the absence of normative Annex B. (1) Bolts, nuts and washers according to DIN 6914, 6915 and 6916 can be used as an alternative.

3.3.3

Other types of preloaded fastener

D SF

High strength bolts can only belong to grade 8.8 at least. The other types of preloaded fastener shall have a confirmed authorised approval for use or other corresponding reliable report.

3.3.4

Rivets

IRL

Reference Standard 5, Rivets, is absent and there is no equivalent document available in Ireland.

3.3.5

Welding consumables

D

Only welding filler metals and auxiliary materials that are permitted by the ‘Framework conditions for the approval of welding filler metals and auxiliary materials for the building inspectorate sector’ are permitted. (1) Standards referred to in BS 5950–2, may be used in the absence of Reference Standard 4, Welding consumables.

IRL

34


4

SERVICEABILITY LIMIT STATES

4.1

Basis

DK

A(1) Elastic buckling of for example panels (initial buckling) may be relevant as a serviceability limit state. The things mentioned under (3) are cancelled. For bridges the maximum stress according to elastic theory shall not exceed fy in the serviceability limit state. (1) Restrictions on deformations with regard to the appearance of the structure are cancelled and are left to be decided by the client.


NL S

4.2

Deflections

4.2.1

Requirements

B

(5) In ultimate limit states calculations, initial imperfections for both members and frames are taken into account; it is not intended that these imperfections, which are in the form of initial deformations, should be taken into account when calculating deflections. It is permissible to calculate the deflections with reference to a structure without imperfections, as if it and its component structural elements were perfect in respect of their geometry. (1) With regard to competent authority, serviceability requirements as specified in Clause 4 are initially a matter between the client or future user of the building and the person responsible for constructing the building, called the designer here. If the cooperation of an authority is required to maintain official interest, the ‘competent authority’ is the authority responsible for the construction approval, i.e. generally the lower level building inspectorate, subject to any other regulations according to State law. (5) These deflections may be calculated at serviceability limit state making allowance for initial imperfections defined in 5.2.4 as far as this may allow reduction of the number of global analyses to be carried out. After paragraph 5, add the following paragraph 6. (6) If no particular design or construction precautions are taken, the second point of section 4.1.4 (Slenderness) of Part Two of M.D. 14 Feb 1992 should be applied. “Slenderness must not exceed a value of 200 for primary members and 250 for secondary members; in the presence of significant dynamic actions, said values should be limited to 150 and 200, respectively.” The things mentioned under (2), (3) and (4) are cancelled. (5) Assumptions leading to conservative results can be used in the design.

D

F I

NL SF 4.2.2

Limiting values

CH F

Limiting values shall be replaced by paragraph 3 33 of SIA 161. (3) Until the publication of Part 6: ‘Crane Structures’ of ENV 1993 Eurocode 3, Article 7.3 of Standard NF P22–615 – 2nd edition should be referred to. (4) In consequence of amendment of Clause 4 of paragraph 2.2.2.2 as concerns the characteristic value of the wind load, the above-mentioned limiting values are invalidated by values given in the NAD. 35



NL SF

These limits concern residential buildings or buildings open to the public. For other buildings, these limits are agreed between the client, the designer and the authority in charge. Portal frames with gantry cranes: until the publication of Part 6 ‘Crane structures’ of ENV 1993 Eurocode 3, the limiting values are given in the NAD for horizontal deflections at the upper face of each gantry girder. In cases of actions of several gantry cranes, paragraph 7.1 of Standard NF P22–615 – 2nd edition shall be referred to as concerns the combination of these gantry cranes. The things mentioned under (2), (3) and (4) are cancelled. (2) The total deflection of a structure supporting brittle partitions or other corresponding structures shall, after completion of the partition, be less than L / 500 calculated on the basis of the long-term loading situation.

4.2.3

Ponding

NL

Delete this paragraph.

4.3

Dynamic effects

NL

Replace this paragraph by 6.2.2 of NEN 6770: 1991.

4.3.1

Requirements

SF

(3) The required difference of the natural frequency of the structure from that of the excitation source should be defined case by case.

4.3.2

Structures open to the public

S

(1) For bridges with pedestrian and cycle traffic BRO 94, 52.331 applies. (2) and (3) The applicability of the given millimetre value should be checked case by case.

SF 4.3.3

Wind-excited oscillations

D

(3) Due to the unavailability of ENV 1991 Eurocode 1, for demarcation criterion, see 2.1 of the August 1986 edition of DIN 1055 Part 4. See also Annex A to DIN 4131 and, for transverse oscillations, Annex A to DIN 4133. (2) The ovalling oscillations of structures should be investigated case by case.

SF 5

ULTIMATE LIMIT STATES

D

Annex E of this guideline gives a list of the terms of the relevant resistances.

36


5.1

Basis

5.1.1

General

B

(1) Although treated elsewhere, the checks for static equilibrium (2.3.2.4), for fatigue (Chapter 9) and partly for connections (Chapter 6) are relevant for verification of ultimate limit states. (2) The partial factor, (M, used for the verification of the resistance of section Classes 1, 2 or 3, known as (M0, is determined according to the level of quality control given in Table 2 of Section 2.3.3.2 of the NAD. According to statistical results, the partial factor (m 1.10 to 1.15 is suitable only for Fe 360. For Fe 510 (and also for high strength steels) the value of safety factors (m and (m0 should be 1.20 to 1.25. From the formal reasons this fact is not accepted in CSN P ENV 1993–1–1, but when a higher ratio of better steels is used in a structure this reality has to be remembered. (2) The ‘boxed values’ of the partial factors should be

CZ


DK

F NL

S

(M0 =

1,28

(M1 =

1,28

(M2 =

1,56

The partial factor is not related to the material parameter but to the calculated load-carrying capacity of the cross section or the element. In stability investigations partial factors should therefore not be applied to the modulus of elasticity of the yield stress when calculating 8¯. (2) Partial factor, (M0, = 1,0 if the steel products used comply with the ‘NF Acier’ label = 1,1 in other cases. Replace (2) with: The partial factor (M is given for the following cases: – Cross sections of Classes 1, 2 or 3: (M0 = 1,00 – Cross section of Class 4: (M1 = 1,00 – Stability of members: (M1 = 1,00 – Net cross sections near bolt holes: (M2 = 1,25 – Connections: see Chapter 6. The factors (MO and (M1 shall be replaced by 1.05(n and (M2 by 1.20(n, with (n according to BKR 94, 2:115.

5.1.2

Frame design

B

(1) These verifications are done under the load combinations related to the ultimate limit state, which are defined in Chapter 2.

5.1.5

Beams

S

For bridges consideration shall be given to the requirements in accordance with BRO 94, 52.211 and 52.212.

37


5.1.6

Members with combined axial force and moment

B

(1) The reference in 5.1.5 to the resistance criteria for members subject to bending does not imply that the member need be checked under the action of the internal forces considered separately. It is intended simply to draw attention to the fact that the last three phenomena listed in 5.1.5 may govern the resistance of the member.


Table 5.2.1 Design assumptions UK

In continuous framing, with elastic global analysis, rigid connections need not be full strength. Similarly in continuous rigid-plastic global analysis, full-strength connections need not be rigid. In rigid-plastic global analysis, where full-strength connections are not needed to resist the internal forces and moments, partial-strength connections may be introduced provided that they are remote from plastic hinge locations.

5.1.8

Fatigue

B

NL

(4) The risk of fatigue from crowd movements can generally be neglected provided that the structure complies with 4.3.2. (3) ENV 1993–1–3 Eurocode 3: Part 1–3 is in preparation. (4) As concerns crowd-induced vibrations, except for exceptional cases, the criteria of paragraph 4.3.2 are sufficient to prevent the risks of fatigue. Replace this paragraph by 5.2.3 of NEN 6770: 1991.

5.2

Calculation of internal forces and moments

B

Global analysis consists, by definition, of the determination of the effects of actions, or internal forces and moments, in a framework subject to the specified loads. 5.2 deals particularly with plane frames loaded in plane. Although not explicitly stated, the more detailed considerations that it contains more often apply to rectangular frames with prismatic members, having constant cross section throughout their length. The application of the rules in this Section to the case of portals with pitched roofs and/or made with tapered members, raises questions that the current edition of Eurocode 3 does not answer completely. In the case of space structures, it is up to the designers to judge whether they should use the rules of plane frames or adapt the principles given in EC3 to suit the behaviour of space frames.

5.2.1

Global analysis

D F

5.2.1.1 Methods of analysis B S

(4) Beam-column assemblies cannot always develop the plastic resistance of the beam or the column. (3) Global analysis of bridges shall be performed in accordance with the elastic theory, except for accidental loads for which the limit state theory may be applied.

38


5.2.1.2 Effects of deformations B

(1) When first-order theory is used, the internal forces and moments obtained are in equilibrium with the external loads acting on the undeformed configuration of the frame. The use of second-order analysis ensures consistency between the internal forces and moments and the displacements. In effect, equilibrium is obtained taking account of the deformation of the frame. This cannot always, in principle, be obtained except at the price of iterative calculation. Analysis using second-order theory should not be confused with the methods given in 5.2.1.2(2)(c), which start with a first-order analysis but then evaluate corrections to be made to represent, indirectly, and of necessity approximately, the second-order effects. (2) There is one case where the use of a second-order analysis is imperative, that of flexible frames, for which it is necessary to take account of the global analysis of the imperfections of members that are highly stressed in compression [see 5.2.4.5(3), which refers to the case described in 5.2.4.2(4)].


5.2.1.3 Elastic global analysis B

F

(2) This allows the use of plastic verification of cross sections for the effects of internal forces obtained from elastic analysis. Figure 5.1 in this NAD summarises the various possibilities offered to the designer in the case of elastic global analysis. It is made up of an organogram that nevertheless has ramifications, the meaning of which only becomes clear by reading certain Clauses. (3) The peak moment is a local maximum on the bending moment diagram, either at the ends of the structural element or at concentrated loads. This rule authorises the arbitrary redistribution of moments in a frame made up of sections that are Class 1 or 2, even though it has been analysed elastically; this redistribution is nevertheless only partial due to the low rotation capacity of the sections concerned. (3) Reducing a peak elastic moment Mpeak in a member is only allowed as far as the considered section is restrained against lateral-torsional buckling. Taking into account the 15% limit, the redistribution shall therefore be possible only if this peak moment is such as: Mpl.Rd # Mpeak # Mpl.Rd / 0.85

S

The amplitude of the moment reduction in the considered section is fixed because it consists of bringing the peak moment down to Mpl.Rd. The moment portion )M that is to be redistributed is then: )M = Mpeak – Mpl.Rd Two sections (e.g. both ends) in a single member may be concerned, as well as several successive stages. In these cases, the 15% redistribution limit shall be checked only between the initial peak moments and those achieved after the redistribution. (1) When calculating the effect of restraint for bridges in the ultimate limit state, the elastic modulus may be divided by (M0. (3) Must not be applied for bridges.

39


5.2.1.4 Plastic global analysis B

S

Figure 5.2 of the NAD summarises the various possibilities offered to the designer in the case of global plastic analysis. See Annex D of the NAD. (1) When a plastic global analysis is used, the plastic resistance of the sections of the members submitted to a risk of instability may be calculated with partial factor (M1 instead of (M0. This allows consistency between the strength assumption adopted in the global analysis and that retained in the member resistance criteria. (3) Subject to a particular justification, this lateral restraint is to be provided at the compression flange. (8) Stress-strain curve according to BSK 94, 3:43 can be used.

5.2.2

Design assumptions

D F

5.2.2.1 Basis B


F

(3) The typology of the modelling serves no purpose. Consequently 5.2.2.2 to 5.2.2.4 are invalidated, as well as the related parts of Table 5.2.1. (3) Because the framing typology is not applicable, paragraphs 5.2.2.2 to 5.3.3.4 are invalidated, as well as the relevant parts of Table 5.2.1. Consequently, paragraph 3 is invalidated and replaced with: The non invalidated part of Table 5.2.1 shows the required connection type according to the global analysis method used.

5.2.2.2 Simple framing B F

Serves no purpose (see Annex H, which is in preparation). Because the framing typology is not applicable [see 5.2.2.1(3)], paragraphs 1 to 2 are invalidated.

5.2.2.3 Continuous framing B D

F

Serves no purpose (see Annex H, which is in preparation). This is understood to mean rigid connections and joints that are modelled rigidly in the elastic range and therefore produce a continuous elastic curve. For continuous structures calculated according to the theory of elasticity, a semi-rigid connection does not have to be designed as full strength. For continuous structures calculated according to the rigid-plastic method, rigid connections may also be of partial-strength design as long as their resistances are taken into account when calculating the internal forces and moments and they have an adequate rotation capacity. Because the framing typology is not applicable [see 5.2.2.1(3)], paragraphs 1 to 3 are invalidated.

5.2.2.4 Semi-continuous framing B D

Serves no purpose (see Annex H, which is in preparation). This is understood to mean framing in which deformations may occur in the connections and joints in the elastic range with the result that the bending deformations show buckling. 40


F I

Because the framing typology is not applicable [see 5.2.2.1(3)], paragraphs 1 to 3 are invalidated. Due to the lack of structural experience associated with this topic, designers who cannot rely on solutions supported in the technical literature by reliable theoretical and experimental references, must prove their design assumptions through experimentation.

5.2.3

Structural systems

D

Clauses 5.2.3.4, 5.2.3.5 and 5.2.3.6 reference Annex H, but Annex H is not yet available, so Annex B of the NAD gives references. Replace the reference in Sections 5.2.3.4, 5.2.3.5 and 5.2.3.6 to Annex H by a reference to the modelling according to 10.1 of NEN 6770.

NL

5.2.3.4 Simple framing B F


IRL UK

Serves no purpose. (1) Because the framing typology is not applicable [see 5.2.2.1(3)], paragraph 1 is invalidated. (1) In the absence of ‘Modelling of structures with simple framing’ in Annex H, use BS 5950–1. Pending the issue of Annex H of EC 3: Part 1.1 interim design rules for columns in simple framing are given in Annex B of the NAD.

5.2.3.5 Continuous framing B F IRL

Serves no purpose. (1) Because the framing typology is not applicable [see 5.2.2.1(3)], paragraph 1 is invalidated. (1) In the absence of Annex H “Sub-frames for global analysis of rigid jointed frames”, BS 5950–1 may be used.

5.2.3.6 Semi-continuous framing B F

Serves no purpose. (1) Because the framing typology is not applicable [see 5.2.2.1(3)], paragraph 1 is invalidated.

5.2.4

Allowance for imperfections

5.2.4.1 Basis B

(2) The definition of equivalent geometric imperfections does not apply except as a calculational device; it does not in any way constitute a fabrication or erection tolerance. (3) The Eurocode requires the effects of the global imperfections of the structure and those of the member imperfections to be taken into account. These imperfections should be considered once and once only, together or separately, either during analysis or during the checking of elements. This explains by example the biggest part of the branching of the organogram given in this NAD at Clause 5.2.1.3.

41


5.2.4.2 Method of application B

F


I

(2) The global frame imperfections are taken into account either by adopting an initial geometric frame geometry with imperfections or by applying equivalent imperfection loads to a perfect structure. It is nevertheless permitted not to consider the global imperfections when the possible horizontal loads generate horizontal displacements at least equal to those that corresponded to the prescribed initial imperfection. (4) Condition 5.1 corresponds to N Sd > Ncr / 4 where Ncr is the critical elastic axial load (for buckling in the plane of the frame) of the element assumed to be pinned at both ends and NSd is the absolute value of the design value of the axial force (in compression). The member imperfections to be taken into account in the global analysis may be limited just to those members corresponding to condition 5.1. (2) The effects of the global frame imperfections may usually be disregarded in the combinations of actions with significant horizontal loads such as wind loads. Replace paragraph 4 with the following text: The effects of member imperfections (see 5.2.4.5) may be neglected when carrying out global analysis when the equivalent geometrical imperfections of the frame defined in 5.2.4.3 are used; in cases where the maximum allowed geometric imperfections for the frame (see 7.7 of EC 3) are used in the analysing, the equivalent imperfections of the members (defined in Fig. 5.5.1 of EC3) must also be considered.

5.2.4.3 Frame imperfections B

D

(1) The factoring of the basic out-of-plumb imperfection N0 by the coefficients kc and ks takes account of the low probability of all the columns of all the storeys having the maximum out-of-plumb amplitude, N0, in one and the same direction. (2) The average vertical load is the total vertical load applied to the a frame in the relevant plane, divided by the total number of columns in the plane. (4) For global analysis, all the columns in the frame have the same outof-plumb amplitude N in the same direction; the direction of the out-ofplumb ought to be considered to be towards the left or the right, depending on which is most unfavourable. (5) This Clause is to be taken into consideration when the global analysis is carried out taking into account the spatial character of the frame. (7) and (8) When, to take account of the effect of global imperfections of the frame in the analysis, the equivalent horizontal forces are used, care should be taken not to include them when determining horizontal reactions – needed, for example, for the foundation calculations. They should either be subtracted manually from the reactions obtained, or else equal and opposite equivalent horizontal reaction forces should be applied directly to the bases of the columns as external forces. In this respect, Figure 5.2.4 may advantageously be corrected by adding horizontal reactions N(F1 + F2 + F3) / 2 acting to the left at each of the two column bases. (1) The use of equation 5.2 for determining frame imperfections is limited to normal building construction buildings.

42


5.2.4.4 Imperfections for analysis of bracing systems B


F

5.2.5

(1) Factoring the basic imperfection by the coefficient kr reflects the low probability of all the stabilising elements having the same initial maximum imperfection amplitude L / 500, acting in the same direction. This Clause requires, in principle, analysing all the beams concerned together with their imperfections, the bracing system and the connecting restraining members as a whole. In practice, this step is difficult to achieve and it will probably be preferable to adopt the alternative given in 5.2.4.4(2), consisting of analysing just the bracing system under the effects of additional transverse forces equivalent to the aforementioned imperfections. (3) This Clause implicitly assumes that beams are of constant height and under simple bending. In the case of a beam of variable height and/or subject to combined axial load and bending, it is possible to determine the force N by adjusting (5.4) in the appropriate manner. (4) If a splice is made in a beam or a compression element, at the joint there should be a restraint capable of supplying a force of at least krN / 100, where N is the resultant compression in the section at the joint. This force shall be transmitted by the two connecting restraining members situated on each side of the splice, applying the rules of statics for pin-ended members. (3) For the design of the bracing system, the equivalent force q belonging to each beam may, in this case, be applied only to the compression length of the stabilised member, and N takes the maximum value of the compressive force. Sway stability

5.2.5.1 Sway stiffness B

It is necessary to distinguish between classification as braced frames and non-braced frames, and classification as sway and non-sway frames. It would have been better, to follow practical procedure, to present the contents of Clauses 5.2.5.2 and 5.2.5.3 in the reverse order. It is necessary to reflect on the braced or unbraced character of the frame under consideration. If the frame is found to belong to the class of braced frames, it can be treated as a non-sway frame. It is only in the case when it is in the class of unbraced frames that it is important to examine its sway or non-sway characteristics, in order to determine the most appropriate analysis method. (1) This Clause implicitly admits that one is considering plane frames. The lateral deformation corresponds to the horizontal displacement of the nodes (intersection of beams and columns) in plan.

5.2.5.2 Classification as sway or non-sway B

(1) Non-sway frames do not require second-order calculations. Firstorder analysis is therefore always authorised for the combinations of forces under which a frame may be considered as rigid. (3) This means that, for the given combination of actions, the critical amplification factor "cr (that is to say the number by which it is necessary to multiply the individual vertical components Vsd of the forces applied to the frame in order to reach theoretical in-plane elastic buckling 43


D


F

of the frame according to a configuration of displaceable nodes) must be greater than 10 for the frame to be classified as non-sway. The frame can thus be sway for certain combinations of actions and non-sway for others. (4) The application of the formula 5.6 requires the beams to be horizontal or at a small slope (< 20%) and the lines of beams at each storey not to be interrupted. (1) is to be replaced by: A frame may be classified as non-sway if the additional internal forces or moments arising from horizontal displacements or its nodes, are negligible. This may be assessed with criterion 5.5 or 5.6. (4) When using criterion 5.6, the effects of the frame imperfection shall be taken into account when determining the individual parameters (*, H, V). (4) Single-storey portal frames may be considered as a particular case to which this method applies. In the case of single- or double-sloped roofs, it shall not apply, unless a particular justification is provided, if the slope exceeds 20%. Generally, in order for this method to be applicable, the beams must not be interrupted within the frame.

5.2.5.3 Classification as braced or unbraced B

(1) This classification only concerns the frames of multi-storey buildings with a bracing system at each level, and which can, by sub-structuring, be separately analysed considering the frame stabilised and the bracing system. In addition, it must be possible to consider, with adequate precision, that the horizontal forces are applied at the lines of beams. In the contrary case, account needs to be taken of the moments generated by these forces in the stabilised frame. (2) This reduction should be verified for the horizontal displacement relative to every storey of the frame. (3) A braced frame can thus always be analysed as first order and the buckling lengths are those for the non-sway mode.

5.2.6

Frame stability

5.2.6.1 General B

(1) The verification of the global stability of a braced frame or a non-braced frame but non-sway, is limited to the verification of the stability of its elements, for which the buckling lengths are those for the non-sway mode. (2) This Clause applies to special cases. For example, in a multi-storey frame, pattern loading on the beams can be more critical for certain columns than the sway mode, because it can lead to buckling of the columns in single curvature, whereas the sway mode induces double curvature.

5.2.6.2 Elastic analysis of sway frames B

(1) See 5.2.6(5) for the definition of “sway moments”. (2) This only applies if the member imperfections have not already been taken into account in a second-order frame analysis. In this case, the 44


stability of these elements still remains to be verified, and must include the effect of the member imperfections; the use of buckling curves provides for this (see Clause 5.5). However, because the effects of sway have already been taken into account in the determination of the internal moments and forces, the non-sway mode buckling lengths can be adopted. (3) The amplification factor "cr can be written as:


1 1 & (1 / "cr) (4) In terms of the critical amplification factor, this method can not be applied if "cr < 4. (5) In the case of frames in multi-storey buildings, in general it can be assumed, with adequate precision, that the sway moments are those that result, at the ends of the members, due to the horizontal forces (actual forces and possibly equivalent global imperfection forces) applied to the frame. Insofar as it can be assumed that the horizontal forces are applied at the nodes (intersections of beam-columns), it is permissible to take into account the second-order effects directly at the level of first-order global analysis by applying the amplification from paragraph 3 to these horizontal forces (actual forces and possibly equivalent horizontal forces representing the global imperfection of the frame). In other types of frames, or for building frames where severe asymmetry, either of the frame itself or of the mode of application of the vertical forces, leads to significant sway solely under the action of vertical forces, the sway moments are those obtained in the frame elements as a result of the following procedure: (a) as well as the actual supports, the nodes (intersections of beams and columns) of the frame are restrained against horizontal movement, and the global analysis is carried out for the load case under consideration (b) the horizontal reactions of the restrained nodes are determined (c) a global frame analysis is carried out with only the actual supports, the frame being loaded only by the reactions determined from step b. The bending moments obtained are the sway moments. The moments that would result from second-order analysis are thus equal to the sum of: – the moments obtained in (a) – the moments obtained in (c) increased by the amplification factor: 1 1 & VSd / V cr

D

(6) The quantity (* / h).(V / H) has to be calculated for each storey, and the largest value used for evaluating the amplification factor. (1) and (4) The frame imperfections in 5.2.4.3(1), equation 5.2 only apply to sway frames if Vsd / Vcr # 0,25. If Vsd / Vcr > 0,25, the above frame imperfections may only be used for calculation if the rigidity EI is simultaneously reduced by 10%.

45


I

SF

Replace paragraph 4 with the following text: In cases where the ratio Vsd / Vcr is greater than 0,25, the second-order effects must be directly included in the global analysis, and the use of indirect methods, as specified in preceding paragraph 1, is not permitted. Replace paragraph 8 with the following text: When first-order elastic analysis is used with sway-mode in-plane buckling lengths for column design, the sway moments in the beams, in the columns and in the beam-to-column connections should be amplified by at least 1,2, unless a smaller value is shown to be adequate by analysis. (8) When the resistance of a column cross section is verified, the moments in the column should be multiplied by the same number.

5.2.6.3 Plastic analysis of sway frames B D


F

(3) and (4) are invalidated. (1) and (4) The frame imperfections in 5.2.4.3(1), equation 5.2, only apply to sway frames if Vsd / Vcr # 0,20. If Vsd / Vcr > 0,20, the above frame imperfections may only be used for calculation if the rigidity EI is simultaneously reduced by 10%. (3) and (4) The procedure is not clearly defined. So, because the reliability of the rigid-plastic method applied to sway frames has not been demonstrated as a general rule, (3) and (4) as well as Figure 5.2.8 are to be invalidated.

5.2.7

Column requirements for plastic analysis

B

(4) It is necessary, as in 5.2.6.3(5), to take account of the influence of plastic hinges in the determination of buckling lengths. (5) The first part of this paragraph, which makes reference to 5.2.6.3(3)b, is invalidated, as 5.2.6.3(3)b has previously been invalidated. (1) Only plastic hinges occurring at member ends may be accepted in compression members with a risk of buckling. In this case, in addition to the requirement of being provided with a sufficient rotation capacity, these plastic hinges must correspond to a plastification restricted to a short length of the member (notion of a ‘concentrated’ plastic hinge). (5) See the validation of Clause 5.2.6.3(3)b. So, any reference to that Clause is no longer applicable.

F

5.3

Classification of cross section

5.3.2

Classification

B

(3) The classification of a section is made, in principle, on the basis of the distribution of direct stresses resulting from the combined action of bending moment and possible axial forces. (8) The upper limits for the width to thickness ratios of compressed elements of Class 3 paradoxically do not coincide with those that can be deduced from the calculation of the effective width [see 5.3.5(3) taking D=1 (fully effective)]. Only the values given in Table 5.3.1 should be used for the classification of sections. It is enough for the thickness of one of the compression elements of a section to exceed the relevant limit for Class 3 for the section to belong to Class 4. 46


5.3.4

Cross-section requirements when elastic global analysis is used

B

(1) The classification of sections decides the partial factor ((M0 or (M1) to be utilised for the determination of the cross-section resistance. Table 5.3.1 – Sheet 1. For a web in combined bending, the position of the elastic or plastic neutral axis cannot be found unless the internal forces are known, following the global analysis; this consequently involves verification of the classification of the web, and therefore of the section, after the analysis. Table 5.3.1 – Sheet 2. In the case of uniformly compressed sections, the plastic redistribution of the stresses in the section does not require any plastic rotation capacity; this is why these limiting values for depth to thickness ratios are identical for Classes 1, 2 and 3. (4) ENV 1993–1–3 Eurocode 3: Part 1–3 is in preparation, therefore apply element 405 in 4.3.1 of DASt Ri 016 “Design and construction of structures made of thin wall cold formed members”. (5) ENV 1994–1–1 Eurocode 4: Part 1–1 is available in English; the German version (DIN V ENV 1994 Part 1–1) is in preparation. The things mentioned under (4) and (5) are cancelled. (6) An upper limit for the slenderness of beam webs in Class 4 is given in Clause 5.7.7 in SS–ENV 1993–1–1, Edition 1.

D


NL S 5.3.5

Effective cross-section properties of Class 4 cross sections

B

(1) In general the effective sections only influence the verification of sections and not the analysis, which is normally carried out using the properties of the gross sections. (2) An internal element has its two longitudinal edges supported, whereas an outstand element has one edge supported and one edge free. A stiffened edge does not constitute a support unless it has sufficient stiffness (see Eurocode 3: Part 1.3). The widths of the tension zones are fully effective. (3) If for some reason the full material resistance is not exploited, one can, in the expression for 8¯p, replace the elastic limit f y by (M1F, where F is the maximum effective compression stress under factored loads (see 5.4.8.3). (4) Strictly speaking, the coefficient R, which is mentioned here, should be calculated on the basis of the stress distribution in the effective section made up from the effective widths of the elements (see Tables 5.3.2 and 5.3.3); it is nevertheless permissible to determine this coefficient on the basis of the distribution of stresses in the gross section. (6) For calculating the properties of Class 4 sections, account must be taken of the displacement of the neutral axis under the combined effect of bending moment and axial force. (7) The displacement e N of the centre of gravity that is considered here is to be determined on the basis of a section subject to axial force only. For an I section, bending about the axis of symmetry parallel to the flanges, eN = 0. Elsewhere, one also has eN = 0 in the case of an axial tension force, because the section is fully effective. (8) The calculation of the reduced slenderness, 8¯p, on the basis of the maximum stress (M1F, is not allowable if the check is according to the criterion (5.39) of Clause 5.4.8.3. It is clear that this approach cannot 47



F

SF

be used in the evaluation of the resistance terms, and more particularly for the determination of the properties Aeff and Weff for use in the verification procedure according to 5.40. This leads to the need for paragraph 9. (9) The calculation of the reduced slenderness of elements should be based on the yield strength fy for the verification of sections according to 5.40. (1) As a rule, the global analysis of statically indeterminate frames shall be carried out using the gross cross-section properties. However, in cases where sections with Class 4 flanges are used and where the local buckling is likely to affect significantly the distribution of internal forces and moments through the frame, a global analysis should be carried out on the basis of the effective cross-section properties. (2) It should be noted that the upper limits of the width-to-thickness ratios defined for Class 3 in Table 5.3.1 do not equate with those resulting from the effective section calculations [see 5.3.5(3)] assuming D = 1. Due to this non-coherence, the application of the method stated in 5.3.5 to Class 4 elements with a b¯ / t slenderness near the upper limit slenderness for Class 3 (see Table 5.3.1) may lead to effective width values lower than the widths of the limit elements for Class 3. In this case, the latter values should be adopted for the calculations. (3) Because stresses are limited to fy / (M1 in Class 4 cross sections, fy may be replaced with fyd = fy / (M1 in the calculation of 8¯p. This possibility does not apply to the cases mentioned in 5.3.5(9). In Tables 5.3.2 and 5.3.3, buckling factors kF are given in the unfavourable assumption where the element is assumed long enough so that the transverse edge support conditions have no significant influence. In other respects, for the calculation of kF, more accurate values given in specialised publications may be adopted instead of the proposed polynomial approximations, providing that those values are established for elements hinged on their support lines. (7) In the case of an axial force, criterion 5.4.8.3(1) may also be applied considering an effective cross section calculated with methods (a) or (b) of the comment of 5.3.5(1). Attention should be paid to the fact that, within the approximate method given in 5.4.8.3(2), the effect of )M is calculated on the effective cross section determined under bending only. (2) The slenderness of the outstand compression elements presented in Table 5.3.3 shall fulfil the condition 8p # 1.06 unless the effects of large deformations are investigated separately.

5.3.6

Effects of transverse forces on webs

D

(3) ENV 1993–2 Eurocode 3: Part 2 is not yet available, so apply element 605 of 6.2 of DASt Ri 015 “Beams with thin webs”. Replace (3) by: The verification has to be done in compliance with Chapter 13 of NEN 6771: 1991.

NL

48


5.4

Resistance of cross sections

5.4.2

Section properties

5.4.2.3 Shear lag effects B

NL S

(2) The effective width of the flange due to shear lag effects in the flange is not to be confused with the local buckling second-order effects in the compression elements, where the distribution of normal stresses is also affected. The effective width of the flange due to shear lag can equally well affect the tension flange or the compression flange. (3) ENV 1993–1–3 Eurocode 3: Part 1–3 and ENV 1993–2 Eurocode 3: Part 2 are not yet available. Shear deformation may be taken into account in accordance with Clause 3 of DIN 18809 and 3.9.2 of DASt Ri 016 “Design and construction of structures made of thin wall cold formed members”. (3) In the absence of ENV 1993–2, “Calculation of effective breadth of flanges”, BS 5400–5 with amendment AMD 3998 may be used. The things mentioned under (3) are cancelled. (3) The manual K18, 18:7 can be used.

5.4.3

Tension

F

(4) For security, ductile behaviour needs always to be required. So, except for any duly justified exception, this requirement shall always be met.

5.4.4

Compression

B D

(5) See Clause 7.5.2 for the definition of oversize and slotted holes. (4) The word ‘buckling’ is the general generic term for possible stability failure of members in axial compression. It includes flexural buckling, torsional buckling and flexural/torsional buckling.

5.4.5

Bending moment

D


IRL

5.4.5.2 Bending about one axis B F

S

(1) If the section has a Class 4 web, as long as the compression flange is in Class 1, 2 or 3, (M0 can be substituted for (M1. (1) In the case of Class 4 box or I section simply bent in the web plane(s) and with Class 1 or 2 flanges, a simple design resistance moment Mc.Rd, determined as in (1) for Class 4 but using (M0 instead of (M1, may be adopted. This possibility shall not be considered if the members are to be checked according to Section 5.5. (1) If moment capacity corresponding to a rectangular stress distribution is utilised for bridges, the beam shall satisfy the requirements in accordance with BRO 94, 52.132.

5.4.5.3 Holes for fasteners B

(4) See Clause 7.5.2 for the definition of oversize and slotted holes.

49


5.4.6

Shear

B

(2) Contrary to the meaning of this symbol used earlier, here d means the depth of the web taken as the distance between the inner faces of the flanges. (8) This is invalidated and should be replaced by: It is not necessary to take into account the holes for fasteners in the web if: Av.net Av

$

fy (M2 fu (M0

If Av.net does not meet this requirement, the effective area shall then be calculated by: Av.eff = Av.net D


F

SF

fu (M0 fy (M2

(7) The values apply to plate edges supported on both sides. For plate edges supported on one side (e.g. flanges of I section subject to shear forces Vy), reduced values are to be assumed. (2) Depth d should be taken as the distance between the inner faces of the flanges. (8) In order to be consistent with 6.5.2.2, and by analogy with 5.4.5.3, Clause 8 is to be replaced with equation 5.21, given in the NAD. (8) Holes in a web should always be reduced in the shear resistance calculation.

5.4.7

Bending and shear

B

The note at the end of Clause 5.4.7 should be invalidated and should read: Note: 5.4.7 only applies if the conditions of 5.4.6(7) are not satisfied.

5.4.8

Bending and axial force

UK

As an alternative to the formulae in 5.4.8 of EC3: Part 1.1, the theoretical reduced plastic resistance moment of a cross section in the presence of axial force may be used.

5.4.8.1 Class 1 and 2 cross sections B D

(11) It is necessary to clarify that the I or H sections must be doubly symmetric. (2) What is meant by a plate here is a rectangular cross section.

5.4.8.3 Class 4 cross sections B

(1) For the calculation of Fx,Ed, it is appropriate to incorporate the necessary additional moments )M = N.e, where the eccentricity e is due to the shift of the neutral axis of the reduced section under the combined effect of bending moment and axial load. (2) Contrary to the relation 5.38, which represents the verification according to 5.37, the criterion expressed by 5.40 should be interpreted 50



D

in an approximate safe-sided way to limit the direct stress (5.39) at the point where the section is most highly stressed. (2) Condition 5.40 does not take into account the effect of any warping stresses. See element 359 of 3.11 and element 416 of 4.3.8 of DASt Ri 016 “Design and construction of structures made of thin wall cold formed members”.

5.4.9

Bending, shear and axial force

B F

5.4.9 only applies if the conditions of 5.4.6(7) are not satisfied. (3) This Clause is applicable to Class 1, 2, 3 and 4 sections. It is advisable to check that the corresponding resistance MN.Rd (or Mc.Rd) is not exceeded.

5.4.10

Transverse forces on webs

B F

(9) It is also necessary to check the crushing resistance of the web according to 5.7.3. (9) It is advisable to check also the crushing resistance (see 5.7.3).

5.5

Buckling resistance of members

SF

(1) The buckling resistance of members in Clause 5.5 means the stability of members generally.

5.5.1

Compression members

P

The slenderness, 8, should not exceed 200; this limit may reach 250 for braced members or secondary elements. Tension elements that are also subjected to compression by wind reversal must not exceed a 8 of 350. For elements subjected to fatigue, the slenderness should be limited to 160. The value of maximum slenderness, 8, should not exceed the following: – for members resisting loads other than wind loads 180 – for members resisting self weight and wind loads only 250 – for any member normally acting as a tie but subject to reversal of stress resulting from the action of wind 350. A member with slenderness greater than 180 should be checked for self weight deflection using the method in 4.7.3.2 of BS 5950–1:1990. With regards to the buckling length, where no guidance is given in EC3: Part 1.1, the nominal effective lengths for a strut given in 4.7.2 of BS 5950–1:1990 should be used.

UK

5.5.1.1 Buckling resistance B

D

(1) The buckling of a compression element need not be considered if the reduced slenderness 8¯ is less than or equal to 0,2. (3) These modes of buckling can notably intervene when the section of the compression element is not symmetrical and constitutes a Class 4 element. (3) Reference to ENV 1993–1–3 Eurocode 3: Part 1–3, proof of torsional buckling and of flexural-torsional buckling and of pure compressive stressing shall be provided in accordance with element 306 of 3.2.2 of DIN 18 800 Part 2 (November 1990 edition) or element 438 51


F NL S SF

of 4.5.2.2 of DASt Ri 016 “Design and construction of structures made of thin wall cold formed members”. (1) The buckling risk for a compression member is not to be considered if 8¯ # 0,2 where 8¯ is the non-dimensional slenderness defined in 5.5.1.2(1). The things mentioned under (2) and (3) are cancelled. (3) The manual K18, 18:37 may be used. (3) This NAD does not cover Part 1.3 of the Prestandard SFS–ENV–1993.

5.5.1.2 Uniform members


B

DK

(1) The quantities Ncr and 8¯ are determined on the basis of gross section properties. (2) The imperfection factor takes into account the effect of different types of residual stresses, specific to the type of section relevant to the buckling curve concerned, and the out-of-straightness amplitude given in Table 7.2. The rule P = f(8¯) constitutes the buckling curves, Figure 5.3 of the NAD. (5) Additional article: Single angles used as web members in compression are covered by specific provisions given in Clause 5.8.3. (1) The value of the non-dimensional slenderness ratio should be: 8¯ = 1,1($AAfy / Ncr)0,5 = 1,1(8 / 81)($A)0,5 The factor 1,1 in the expression for the non-dimensional slenderness ratio is to ensure that the ratio between the safety for slender and short compression members is the same as in DS 412.

5.5.1.3 Non-uniform members B

D DK

(4) The equivalent initial imperfection is an out-of-straightness amplitude such that, considered alone, it has the same effect on the carrying capacity as the combined action of residual stresses and an outof-straightness imperfection according to Table 7.2. (4) and (5) and Figure 5.5.1; (M1 = 1,10 applies in all cases. (4) An adjustment is made in Figure 5.5.1 for the values k*, which should be added for the case when (M1 = 1,28. A Table in the NAD gives the values of k* for different buckling curves. The values for k* take into account that 8¯ has been increased by 10%.

5.5.1.4 Flexural buckling D

DK

(4) Cold-formed hollow sections shall only be used if their production has been subjected to building inspectorate surveillance. In the absence of corresponding design requirements, the rules of Clause 9 of DASt–Ri 016 “Design and construction of structures made of thin wall cold formed members may be applied”. Figure 5.5.2, for the tests, the following applies: test reports shall contain data on the aim of the test, the planning, apparatus, procedure and evaluation of the test in a form that permits evaluation and also independent repetition of the tests. (3) The slenderness ratio 8 should not exceed the values specified in DS 412, paragraph 6.2.8. 52


5.5.1.5 Buckling length B

F


SF

(1) The lateral restraint can be real (columns in triangulated frames for example) or result from the assumption associated with the design model [see the commentary to Clause 5.2.6.2(2)]. (2) Annex E applies particularly to the determination of the buckling length of columns belonging to rectangular frames. Use can be made of any other appropriate means or any recognised methods, where the scope of application may be more general. (2) The buckling length may also be determined by any other appropriate means or admitted method. In any case, the beams restraining the ends of the compression member analysed must be considered as pinned in the maximum or peak moment sections where the elastic resistance moment is exceeded [see Annex E, E.2(8)]. (1) Increased values of buckling lengths should be used when the boundary conditions presented in Annex E are not reliably achievable.

5.5.2

Lateral-torsional buckling of beams

B

(1) This paragraph applies to elements of uniform section subject only to bending about the strong axis, and of which the end sections cannot twist about the longitudinal axis of the element or displace laterally. It can generally be accepted that these conditions are satisfied only if the compressed flange does not displace laterally. Other support conditions can be taken into account by adopting appropriate values for the various coefficients used in the calculation of the critical lateral torsional moment (see Annex F). For I sections of class 3 or 4, non symmetrical relative to the strong axis, which is the axis of bending, $w is calculated from the elastic section modulus relative to the compression flange. The lateral restraint at the ends should be provided by fastening devices and members with sufficient stiffness and adequate resistance. It is generally considered that the bracing elements and fastening devices must be able to: – resist a force equal to 1% of the axial compression force in the compression flange at the restrained sections, transmitted by the flange and acting perpendicular to the plane of the webs of the member stabilised – provide sufficient stiffness to lateral displacement and to rotation in the plane perpendicular to the plane of bending, to justify the choice of the non-dimensional slenderness 8¯LT adopted [see definition in (5)]. (5) The quantities Mcr and 8¯LT are determined on the basis of the properties of the gross section. The slenderness for lateral-torsional buckling is given, for all classes of cross section, by: 8¯LT = B EWpl.y / Mcr In the calculation of Mcr, the influence of the uniform torsional inertia It of the member for a Class 4 section can be left out; the lateraltorsional buckling is thus reduced to the phenomenon of lateral buckling of the compression flange.

53


D DK


F

The requirements given do not cover the case of planned torsion. (8) What is meant is that the compressive flange has to prevent sway. (5) The expression for the non-dimensional slenderness ratio should be: 8¯LT = 1,1($WWpl,yfy / Mcr)0,5 = 1,1(8LT / 81)($W)0,5 The factor 1,1 in the expression for the non-dimensional slenderness ratio should ensure that the safety ratio for beams of extreme slenderness and beams of less slenderness is the same as in DS 412. (1) The lateral-torsional buckling of members bent about one axis with compression, or bent about two axes or without compression, shall be treated, if needed, by applying Clause 2, 4 or 6 of paragraph 5.5.4 depending on the class of the section. In the case of members with non-uniform section, a suitable and justified methodology, developed from the procedure defined for uniform section elements, may be adopted. In the case of Class 3 I sections with unequal flanges, it is advisable to use the elastic modulus Wel.y corresponding to the compression flange whose lateral stability is to be checked. The same holds true for modulus Weff.y of Class 4 sections. The lateral restraint at the ends shall be provided by fastening devices and members with sufficient stiffness and a suitable resistance. Hereafter are the criteria, taken from “Additif 80 to DTU P 22–701 (CM66 Rules)”, that these bracing members and fastening devices must comply with: – resisting force equal to 2% of the axial compressive force in the compression flanges at the retrained sections, this force being transmitted through these flanges perpendicular to the web plane of the members – opposing a sufficient stiffness to lateral displacements and to rotation within the plane perpendicular to the bending plane, to justify the choice of the non-dimensional slenderness 8¯LT retained [see definition in (5)]. Further information is given in the comments to paragraph 5.23 of “Additif 80 to DTU P 22–701 (CM66 Rules)”. (5) The elastic moment for lateral-torsional buckling Mcr shall be calculated with the gross section properties. For Class 4 sections, the calculation of Mcr shall be carried out without considering the torsion constant of the member (It = 0, see Annex F). 8LT is the slenderness of the member with regard to lateral-torsional buckling (see Annex F). (7) When one of the ends of the bent member has a plastic hinge that has ‘rotated’ to allow a redistribution of the internal forces and moments, the lateral restraint conditions near the plastified sections, mentioned in article 5.21 of “Additif 80 to DTU P 22–701 (CM66 Rules)”, must also be complied with in order to disregard lateral-torsional buckling. When a lateral support is provided at a clear length L (free lateraltorsional buckling length) from a plastic hinge (itself laterally supported), and when the bending moment varies linearly (or approximately) over the length L, these conditions may be reduced to: L / iz # 35g

if

L / iz # (60 – 40 R)g if

54

0,625 # R # 1 –1 # R < 0,625


where

P


UK

R

is the ratio of bending moments at ends of the member, the length of which is L (–1 # R # 1, R > 0 if single curvature bending) iz is the minimum radius of gyration of the section. The factor k should not be less than 0,7, unless in special circumstances. The designation of ‘a beam which is perfectly braced’ is included in the same Clause (Annex F), for a beam with a restrained compression flange all along the length. For beams with continuous bracing all along one of the flanges, the curvature by flexural buckling must always be taken into account when the other flange is able to function as a compressed flange that is unbraced. Because this is not dealt with in EC3, any characteristics relative to this situation must be obtained from the specialist literature. Effective length factor. (1) When calculating the elastic critical moment, a value of k (see Annex F of EC3: Part 1.1) less than 0,7 may be used for a member only when it can be demonstrated that the stiffness of the connecting members and of the connections to be used would justify such a value. In all other cases the value of k should not be taken as less than 0,7. (2) For normal loading conditions where no guidance is given in EC3: Part 1.1, the recommendations in 4.3.5 of BS 5950–1:1990 for the effective length of beams and cantilevers with normal loading conditions may be used to determine the value of k. The effective length, LE, referred to in BS 5960–1:1990 is equivalent to the kL term used in Annex F of EC3: Part 1.1. For destabilising loads see Load position below. Load position: For loads above or below the shear centre, the effective length factors in (1) and (2) above should be used, in association with the appropriate value of zg. Buckling resistance moment for single angles. The buckling resistance moment for a single angle should be taken from 4.3.8 of BS 5950–1:1990.

5.5.3

Bending and axial tension

D DK NL

(2) The value of Rvec = 0,8. However, it is pointed out that the same reduction factor is already specified in 2.3.3.1(4). A double application is therefore not meant. (2)–(5) These items should be omitted. (2) Rvec shall be taken equal to Rvec = 1,0.

5.5.4

Bending and axial compression

B

Add the following general comments: (1) When there is no danger of lateral-torsional-buckling, the checking of (5.51) for class 1 and 2 sections or (5.53) for Class 3 sections is only required when the two conditions below are met simultaneously: 8¯ max > 0,2 Nsd / (Pmin A f y / (M1) > 0,1 where

8max = max(8 y,8 z)

and

Pmin = min(Py,Pz) 55


(2) When the criteria of (5.51), (5.53) and (5.56) (relative to the case where there is no danger of lateral-torsional buckling) are to be applied in the case of combined compression and single axis bending, it is more correct to replace Pmin by the reduction factor associated with buckling in the plane of the internal bending moment. One should therefore check:


Nsd / (Pmin A f y / (M1) # 1

D

DK F

(3) If lateral-torsional-buckling is a potential risk (8¯ LT > 0,4), one of the conditions (5.52) or (5.54) or (5.57) should be satisfied, according to the relevant section class. The internal forces and moments to be used in the various resistance criteria given in 5.5.4 are the maximum values of internal forces and moments prevailing along the member. (5) The moduli Weff,y and Weff,z should be calculated for the extreme fibre where the stresses resulting respectively from each maximum internal force and moment Nsd, My.Sd and Mz.Sd along the member have the same sign. Contrary to the case of a fully effective section, the location of the fibre in question cannot be determined before the calculation of the reduced section properties. The symmetry of the section about a principle axis of bending eliminates the corresponding eccentricity eN. The requirements of this Subclause are not applicable if torsion is planned to be present. Equations are given in the NAD for the special case of “bending about one axis M y and axial force N”, for the different classes of cross section. (5) and (6) The verifications are only permitted if the effect of the shear stresses with regard to buckling is negligible. This is regarded as being satisfied if the following conditions are met: JSd # 0,2 Fy / (M1 JSd # 0,3 Jcr / (M1 where Jcr = critical plate buckling stress for shear. (1)–(6) My.Sd and Mz,Sd are the largest moments with regard to the respective axes in the member. Refer to article 5.32 of “Additif 80 to DTU P 22–701 (CM66 Rules)” concerning flexural buckling, further criteria are given in the NAD. (1) In the case of dissymmetrical sections, Wel,y and Wel,z shall be calculated for the extreme fibre where the stresses respectively due to each maximum internal force and moments Nsd, My.Sd and Mz.Sd along the member have the same sign. The NAD describes ‘local second order analysis and checking of the separate member’, which involves local analysis in a main plane of inertia and the checking of a member’s resistance. The criteria associated with bi-symmetrical I-section members are given in the NAD. (2) The buckling resistance check with a risk of lateral-torsional buckling is to be carried out with the internal forces and moments values determined within the global analysis of the frame. This is also true if the buckling resistance check has been carried out with a second-order analysis [see amendment to 5.5.4(1)]. (3) The amendment to 5.5.4(1) is fully applicable to the resistance check of members with Class 3 sections. (4) See amendment to 5.5.4(2).

56


SF


UK

(5) and (6) In the case of bending about both axes, moduli Wel,y and Wel,z should be calculated for the extreme fibre where the stresses respectively due to each maximum internal force and moments Nsd, My.Sd and Mz.Sd along the member have the same sign. (1) The actions shall be placed into the formulae as absolute values. Pmin is the lowest of Py, Pz and PT where PT should be calculated on the basis of torsional buckling. The reduction factor PT should be calculated using buckling class c. In the case of torsional buckling, non-dimensional slenderness should be calculated using the formula: 8T = ($A Npl / Ncr.T)0,5 Ncr.T is the load corresponding to the torsional buckling load in accordance with elastic analysis. The method given here can be applied to structures belonging to cross section classes 1 – 3. The reduction factor PT shall also be applied to the other formulae in Clause 5.5.4, when torsional buckling is determining. Appendix G of BS 5950–1:1990 should be used for the design of restrained members with an unrestrained compression flange.

5.6

Shear buckling resistance

5.6.1

Basis

F

(1) Some notations in Section 5.6 are defined in Figure 5.6.1. It should be noticed that, more particularly, d represents in this Section 5.6 the distance between the inner sides of the flanges, not the depth of web between fillet welds.

5.6.2

Design methods

D

(2) and (7) Because ENV 1993–2 Eurocode 3: Part 2 is not available yet, an alternative check for buckling may be carried out in accordance with DIN 18 800 Part 3. Checking for buckling of webs with longitudinal stiffeners may be carried out in accordance with DIN 18 800 Part 3. (2) Part 2 of Eurocode 3 is absent, therefore use BS 5950–1. (7) In the absence of Part 2 of Eurocode 3, use BS 5400–3 with amendment AMD 3998.

IRL

NL S

The things mentioned under (2) are cancelled. Replace in (7) the reference to ENV 1993–2 by the reference to Chapter 13 of NEN 6771: 1991. BSK 94, 6:261, and the manual K18, 18:26 can be used.

5.6.4

Tension field method

5.6.4.1 Shear buckling resistance B

(4) The longitudinal force Nf,Sd in the flange under consideration is calculated assuming that the moment Msd and the axial force Nsd are applied to a cross section reduced to its flanges only. In the case of Class 4 compression flanges, the term (btffyf / (M0) shall be replaced with (befftffyf / (M1). Thus, MNf.Rk = 0 is effectively found when Nf.Sd reaches the design compressive strength of the flange. 57


F

(4) The longitudinal force Nf.Sd in the relevant flange is calculated assuming that moment Msd and axial force NSd are applied to the cross section reduced to its flanges only. This may be carried out on the basis of a uniform stress distribution in the flanges. In the case of Class 4 compression flanges, the term (btffyf / (M0) shall be replaced with (befftffyf / (M1). Thus, MNf.Rk = 0 is effectively found when Nf.Sd reaches the design compressive strength of the flange.

5.6.4.3 End panels B

(3) and (4) The expressions for M NS and Mpl,3 are written assuming that the end stiffener consists of a single plate. They should be modified for other types of end stiffener.

5.6.7

Interaction between shear forces, bending moment and axial force

5.6.7.2 Simple post-critical method


B

(1) In the presence of an axial force NSd, the moment Mf,Rd is derived from the assumed plasticity criteria as satisfying: Mf.Rd = M°f.Rd

D F

(1 & NSd) Nf.Rd

Nf.Rd is the plastic axial force and M°f.Rd is the plastic moment resistance of the reduced section consisting of the flanges only, but in the absence of axial force; the quantities are calculated with a partial factor (M0 if the section is Class 1, 2 or 3, and (M1 if the section is Class 4. (3) If the section is Class 4, Mpl,Rd is calculated from a section consisting of the non reduced web and the flanges, the width of the compression flange being possibly limited to the effective width if this flange is also Class 4. For Class 1, 2 or 3 sections, Mpl.Rd should be calculated with the partial factor (M0. For Class 4 sections, (M1 is used. (4) and Figure 5.6.4 (a), further explanations can be taken from publication [8], page 120. (1) This NAD gives a formula for M f.Rd, the plastic resistance moment. (3) For Class 4 sections, a ‘virtual plastic resistance moment’, Mpl.Rd, should be calculated over a section consisting of the non reduced web with the flanges, the width of the compression flange being possibly limited to the effective width if this flange is also Class 4. For Class 1, 2 or 3 sections, Mpl.Rd should be calculated with the partial factor (M0. For Class 4 sections, (M1 is used.

5.6.7.3 Tension field method B

(1) The maximum values of MSd and VSd to be used here may act at different cross sections of the panel. (5) See commentary for 5.6.7.2(3).

F

(1) The maximum values of stresses MSd and VSd to be used here may be found in different cross sections of the panel. These values should be considered for the load case under analysis. (5) Refer to the amendment to 5.6.7.2(3) for the calculation of Mpl,Rd.

58



Discuss me ...

5.7

Resistance of webs for transverse forces

S

When a check is made for web crushing below a concentrated load, it is permissible for the calculation to be performed in accordance with BRO 94, 52.151.

5.7.2

Length of stiff bearing

D

(3) For class 2 cross sections (classification according to pure bending), the length of stiff bearing Ss may be determined under the assumption of a dispersion of load at a slope of 1:2,5. This always applies for rolled I and H standard sections. The sentence “No dispersion should be taken through loose packs” is deleted. Load dispersion through loose packs should, however, be checked. Supplementary literature: a reference is provided in the NAD.

5.7.3

Crushing resistance

B

(1) bf is the design width of the flange for transverse forces but is limited to 25tf, where tf is the thickness of this same flange.

5.7.4

Crippling resistance

B

(2) The triple criteria correspond to the tri-linear interaction in the system of axes (F, M) (Figure 5.4 in the NAD).

5.7.6

Transverse stiffeners

B

(6) The dimension sy should be increased by sg when the support reaction is applied over a rigid support length sg. (6) When the support reaction is applied over a rigid support length ss, this value should be added to sy. Design of diagonal, tension and torsional stiffeners. 4.5.6, 4.5.7 and 4.5.8 of BS 5950–1:1990 should be used for the design of diagonal, tension and torsional stiffeners respectively. Bearing stiffeners should be designed in accordance with EC3: Part 1.1.

F UK

5.8

Triangulated structures

B S

See NBN B 51–002. The whole Clause applies as advisory notes.

5.8.1

General

D IRL NL

(4) ENV 1993–3 Eurocode 3: Part 3 is in preparation. (4) In the absence of Part 3 of Eurocode 3 “Lattice towers”, use BS 5950–1. The things mentioned under (4) are cancelled.

5.9

Built-up compression members

B S

See NBN B 51–002. The whole Clause applies as advisory notes. 59


5.9.1

Basis

F NL

(5) In this case, the concerned member is subject to bending and compression, which is not considered in paragraph 5.9. Add: (6) The stability of the built-up member as a whole must be checked according to 12.1.6.5 of NEN 6771: 1991.

5.9.2

Laced compression members

5.9.2.2 Construction details F

(2) If system (b) is to be used, the effect of torsion should be included in the buckling check.


5.9.2.4 Chord forces at mid-length F

(2) For other lacing systems, Sv may be calculated from: Sv = G Aa where G is the modulus of transverse elasticity (see 3.2.5.1) Aa is the area of the equivalent web calculated according to article 13,942 of DTU P 22–701 (CM66 Rules).

5.9.3

Battened compression members

5.9.3.1 Application F

(1) When the battens are bolted to the chords, the connection clearances should be limited so as to meet the rigidity requirement. In the absence of justification, bolt holes shall be drilled at d + 0,5 mm.

5.9.4

Closely spaced built-up members

F

(1) In the case where the packing plates between the chords are connected with ordinary bolts with a clearance, each chord shall be checked separately as concerns buckling. The buckling length shall be taken as the system length of the member. Subject to appropriate justification, the spacing of the packing plates may exceed 15imin. A minimum of two battens over the system length is needed.

5.9.5

Star-battened angle members

F

(1) Subject to appropriate justification, the battens need not be used in pairs. However, they shall be staggered in two perpendicular planes.

6

CONNECTIONS SUBJECT TO STATIC LOADING

6.1

Basis

6.1.1

Introduction

DK

(2) The ‘boxed values’ of the partial factors should be:

60


F


NL

S

(Mb =

1,56

(Mr =

1,56

(Mp =

1,56

(Mw =

1,56

(2) The value of (Mb shall be taken as: (Mb = 1,50 for the resistance of bolts subject to tension (Mb = 1,25 in other cases (bolts subject to shear, punching shear of the bolt head and of the nut ...) The value of (Mw shall be taken as: (Mw = 1,25 for steel Fe 360 (Mw = 1,30 for steels Fe 430 and Fe E 275 (Mw = 1,35 for steels Fe 510 and Fe E 355 (As concerns the symbols used for steel grades, refer to the comment to 3.2.) Replace in (2) the partial factor for the resistance of pin connections, (Mp = 1,00. Replace (3) by: Fatigue values must be verified according to 5.2.3 in NEN 6770:1991. (2) The factors (Mb, (Mr, (Mp and (Mw shall be put equal to 1,20 (n with (n according to BKR 94, 2:115.

6.1.2

Applied forces and moments

B

(2) It is not always required to take account of the second-order effects and/or the initial imperfections (out-of-straightness). See 5.2.5 and 5.2.4 (5.2.4.2 in particular).

6.1.3

Resistance of connections

B

The terms ‘resistance’ and ‘capacity’ mean the same thing. (1) Here ‘fasteners’ means bolts, rivets, pins and other similar components. The resistance of a joint does not depend exclusively on the resistance of the fasteners or of the welds; the other components of the joint also affect this resistance (gussets, splices, plates, webs and flanges of the sections within the connection, etc.). (3) Annex J contains design rules based on yield lines. (3) For the tests, the following applies: test reports shall contain data on the aim of the test, the planning, apparatus, procedure and evaluation of the tests in a form that permits evaluation and also independent repetition of the tests. (3) The plastic failure mechanism within a connection is not always single. The mechanism leading to the lowest resistance shall then be chosen. When this mechanism is evident (simple mechanism), experimental confirmation is no longer justified.

D

F

61


6.1.4

Design assumptions

B

(1)(d) The material behaviour is assumed to be rigid-perfectly plastic and the mechanism of the design model should be kinematically admissible. (2) If doubt exists over the choice of the most rigid path, consideration should be given to the best possible path.

6.1.5


NL

Replace paragraph 6.1.5.

6.2

Intersections

B

(2) Structures made of hollow sections are an example where the effect of eccentricity may be disregarded to some extent (see Annex K). It should be noted that the absence of eccentricity at intersections does not remove the requirement to allow for local eccentricity effects in the design of the connection itself. (3) This simplification is valid only in the case of a single setting out line parallel with the member axis. (3) This simplification is valid only in the case of a single setting out line parallel with the member axis.


F 6.3

Joints loaded in shear subject to vibration and/or load reversal

B

D

(2) The combination of preloaded high-strength bolts and welds is nevertheless allowed [see 6.7 (Hybrid connections)] on the condition that the preload is introduced after welding. (3) At first sight 6.3(3) seems to contradict 6.3(2), when the wind on the braced structures is subject to load reversal. 6.3(3) is nevertheless valid, because in common buildings, displacements due possibly to some slip in this type of connection do not affect the efficiency of the bracing systems and are negligible compared with the frame imperfections defined in 5.2.4.3. The designer can also choose non-slip connections for reasons other than because the loads are reversible: to limit deformations, for example. Similarly for bracing, a friction connection (B or C) can be adopted to increase the fatigue resistance. (1) Injection bolts shall be approved by the building inspectorate.

6.4

Classification of connections

6.4.1

General

B

(2) The most commonly used joints have some deformability, which may be characterised by a moment-rotation diagram (see Figure 6.9.1). For instance, Figure 6.1(a) of the NAD shows the moment-rotation relationship for four well-known joint types. The behaviour is generally non-linear, but in order to make the elastic or plastic global analysis more simple, it may be necessary to identify a stiffness (linear behaviour) or a resistance level (as for a plastic hinge). Figure 6.1(b)

62


from the NAD shows, as a dotted line, an example of a possible approximation for defining the values of these two parameters. (3) In addition, joints designed by an elastic calculation should not be used in a structure analysed on the basis of the rigid-plastic theory, unless the elastic limit resistance of these connections is greater than the ultimate resistance of the members they connect. On the other hand, there is no incompatibility in using connections designed by means of a plastic calculation when the structure is analysed by means of an elastic method (allowing for the stiffness of the connections if these are semi-rigid). 6.4.2

Classification by rigidity

B

Some examples of classification criteria are given in 6.9.6 for beam-tocolumn type joints.

6.4.2.1 Nominally pinned connections


B

For structures subject to static loading, it is not necessary to take into account the moments transferred by the joints to the other elements of the frame, provided that the joints have sufficient rotation capacity. The rotation is that calculated for the structure assuming that the joints are perfect pins. The significant moments are those that have an unfavourable influence on the load-carrying capacity of the frame; they are calculated according to 6.9.6.3(2). To determine whether a connection may be considered as a pin, refer to 6.9.6.2(3).

6.4.2.2 Rigid connections B

F

The deformations of a joint have a significant influence if they have an unfavourable influence on the load-carrying capacity of the frame. These deformations are calculated according to 6.9.6.2. To determine whether a joint may be considered as rigid, refer to 6.9.6.3(4). (2) The 5% requirement may be transferred to the elastic critical value Vcr of the total vertical load applied to the structure (if the latter can be determined more easily than the ultimate resistance). Vcr is defined in 5.2.5.2 and 5.2.6.2. It should be remembered that the value Vcr is calculated using the initial stiffness of the joints [see 5.2.2.1(7)]. (2) ‘Deformations’ refer to those that would be calculated using the behaviour curves of the connections. The beam-to-column connections classified as rigid according to the criteria of 6.9.6 shall be considered as meeting this requirement. The 5% requirement may concern the elastic critical value Vcr of the total vertical load applied to the structure (as far as the latter may be determined more easily than the ultimate resistance). It should be reminded that the value Vcr is calculated with the initial stiffness of the connections [see 5.2.2.1(7)].

63


6.4.2.3 Semi-rigid connections B F

6.4.3

To determine whether a connection may be considered as semi-rigid, refer to 6.9.6.2(6) and (7). When the variable character of the actions may lead to sign inversions of a moment in connections that are heavily stressed in their non-linear range, the adaptability of the structure shall be checked until its ultimate limit state is reached, thus being an exception to Clause 5.2.1.4(11). It shall be checked that when the semi-rigid connections are replaced with pinned connections, the structure does not turn into a mechanism. Classification by strength

6.4.3.1 Nominally pinned connections


B

(2) To determine whether a connection may considered as a pin, refer to 6.9.6.3(2).

6.4.3.2 Full-strength connections B

F UK

To determine whether a connection may considered as rigid, refer to 6.9.6.3(3). (2) ‘Overstrength’ means that the actual resistance of the member is greater than its design resistance. The elastic moment capacity of the joint and the plastic moment capacity of the connected elements are calculated using the design value of yield strength. The actual yield strength is often greater than this value. If the actual elastic moment resistance of the joint is greater than the actual moment resistance of the connected elements, a check on the rotation capacity of the joint is not required, because the plastic hinge will form in the element adjacent to the joint, where the rotation capacity is sufficient if the element is Class I. If the actual plastic moment resistance of the connected elements is greater than the calculated value based on the design yield strength, the hinge may nevertheless form in the joint, hence the need to require a certain rotation capacity from the joint. Nevertheless, if the elastic moment resistance of the joint is at least 1,2 times the plastic moment resistance of the connected members, it may be assumed that the plastic hinge will not form in the joint and the check on the rotational capacity of the joint can be ignored. (2) This factor shall be reduced to 1,0 in the case of full penetration butt joints. (2) This factor shall be reduced to 1.0 in the case of full penetration butt connections. When allowing for overstrength effects by checking whether the design resistance of the full-strength connection is at least 1,2 times the design plastic resistance of the members, the value (Mb for bolts in tension should be taken as 1,2. The rotation capacity of a connection adjacent to a haunch need not be checked provided that the connection is capable of resisting the maximum moments and forces that would result if one or more of the plastic hinges located in the members are overstrength, due to the

64


relevant members having as actual yield strength 1,2 times the specified value. The rotation capacity need not be checked in a full-strength connection immediately adjacent to the last hinge to form, provided that this can be clearly identified. 6.4.3.3 Partial-strength connections


B

F

(1) The concept of partial-strength connection allows the formation of plastic zones within the connection. During global analysis, when the design resistance of the connection is reached, its behaviour may then be considered as that of a plastic hinge. The rotation capacity of the connection can be determined by testing. Testing is not required for details that in practice have been shown to be adequate. Such knowledge exists for a large number of connection types and has been incorporated in the rules given in Annex J. The order in which plastic hinges form in a mechanism depends on the relative stiffness of the elements in the vicinity of the hinges. The largest rotation capacity is needed where the first hinge forms; this is why a limit is applied to the stiffness of semi-rigid connections. (3) The rotation capacity may also be determined by calculation (see 6.9.5 and Annex J). Clause 1 must be invalidated and replaced with: The design resistance of a partial-strength connection is automatically less than that of the connected member. However, it shall not be less than the resistance which is necessary to transmit the design internal forces and moments.

6.5

Connections made with bolts, rivets or pins

D

See also 3.3.2.

6.5.1

Positioning of holes for bolts and rivets

B

The Table given in the NAD summarises the positioning of holes.

6.5.1.1 Basis DK

(2) For plate edges that are not perpendicular to the direction of force, the distance from the bolts to the edges should be outside an ellipsis with semi-axes corresponding to the relevant minimum distances in accordance with the principle used in DS 412, paragraph 6.4.10.

6.5.1.2 Minimum end distance F

(2) In the case of preloaded high-strength bolts, the minimum end distance shall not be less than 1,5d0.

6.5.1.3 Minimum edge distance F

(2) In the case of preloaded high-strength bolts, the minimum edge distance shall not be less than 1,5d0.

65

P255: Discuss

Comparison me

of

National

Application

Documents

for

Eurocode

3:

Part

1.1

and

Eurocode

4:

Part

1.1

...

6.5.1.4 Maximum end and edge distances B

6.5.1.5 Minimum spacing F

of conditions

B

From Figure 6.2 of the NAD, the minimum distance p between the centres of two bolts placed in slotted holes should satisfy the provisions laid down in 7.5.2(9) and (10).

6.5.2

Deductions for fastener holes

6.5.2.1 General B

(1) The definition of oversize holes is given in 7.5.2.6. The design method for compression members is stated in 5.4.4.

6.5.2.2 Design shear rupture resistance B

Use

6.5.2.3 Angles connected by one leg B

Created on 30 March 2011 This material is copyright - all

D

reserved.

(1) In Figure 6.5.5, the relevant ‘block’ appears hatched and represents the part ‘torn off’ during failure. Tensile failure occurs along the horizontal limit of the block, and shear plastic yield occurs along the left vertical limit of the block. The use of oversize or slotted holes in connections of load-bearing members requires the approval of the building inspectorate.

rights

of

this

document

is

subject

to

and

6.5.1.8 Slotted holes

terms

(1) In the case of preloaded high-strength bolts, the minimum value of p1 shall not be less than 3d0. (2) In the case of preloaded high-strength bolts, the minimum value of p2 shall not be less than 3d0.

the

the

Steelbiz

Licence

Agreement

F

Because the connection at the row of fasteners is not continuous, the width-thickness ratio values of Table 5.3.1 (Sheet 3), which are specified for rolled sections according to the class of the plate, should be used, multiplied by a 0,8 reduction factor to prevent local buckling between the free parts of an element. (3) The rule of an edge distance not exceeding 12t or 150 mm, whichever is the larger, defined in (2) may not prevent local buckling. Because the connection at the row of fasteners is not continuous, the width-thickness ratio values of Table 5.3.1 (Sheet 3), which are specified for rolled sections according to the plate, should be used, multiplied by a 0,8 reduction factor.

F

(2) t is the thickness of the attached leg of the angle. Expression 6.4 is applicable to the case of three bolts or more. (2) Expression 6.4 is applicable to the case of three bolts or more.

6.5.3

Categories of bolted connections

S

In the main structure of a road bridge or a pedestrian and cycle bridge, all bolted connections shall be preloaded as Category E (in 66


SS–ENV 1993–1–1, Edition designated Category E but here also for shear connections) and holes ‘fine series’ shall be applied. In crossbracings at supports and at junctions between main beams in a bridge along a horizontal curve, bolted connections shall be close tolerance connections S2F according to BSK 94, 8:51. Connections that are not part of the main structure may be made as Category A or D. 6.5.3.1 Shear connections B

NL

(2) Ordinary bolts are those which belong to a quality class that is inferior to grade 8.8. The quality classes are defined in the standard ISO 898/1 (NBN–EN 20898/1) and Table 3.3. In (3) and (4) replace the reference by ‘Reference Standard 8’.

6.5.3.2 Tension connections


B

NL

(3) Experience has clearly established that: (a) preloaded bolts have but little influence on the connection stiffness beyond a certain dimension (b) preloaded bolts do not increase the ultimate resistance of the connection (c) the details that increase the fatigue strength are those which most reduce the prying forces and, consequently, the stress variations within the bolts. This comment is illustrated by Figures 6.3 and 6.4, given in this NAD. In (3) replace the reference by ‘Reference Standard 8’.

6.5.4


B

(1) This proportional distribution only relates, on Figure 6.5.7(a), to the forces due to a moment. The shear forces are evenly distributed between the fasteners. (2) The plastic distribution of forces in Figures 6.5.7(b), (c) and (d) may not be permissible in some situations. As a replacement, the plastic design method given in the NAD may be used. (1) A plastic distribution of stress resultants on the individual bolts in a bearing type connection with non-fitted bolts should only be allowed if the shear resistance of the bolts exceeds the bearing resistance. Also, an elastic distribution of forces on the bolts in a slip-resistant connection should generally be assumed. (2) The plastic distribution of forces in Figures 6.5.7(b), (c) and (d) may not be allowed in some situations. They may be replaced with the plastic design method, as stated in the NAD.

DK

F

6.5.5

Design resistances of bolts

B

(8) The first condition shall also apply to grade 8.8 bolts. (11) In certain cases, Table 6.5.4 can give values of bearing resistance that are slightly more than those in Table 6.5.3. The expression ‘conservative values’ in Table 6.5.4 is not really correct. The values in Table 6.5.3 should be used. 67


D

DK

(4) Generally, two calculations are to be carried out (for bolt head and nut) to determine the design punching shear resistance. The calculations may be dispensed with if the following condition is met in each case: tp $ 0,5 x d where d = bolt diameter (applies for d # 36 mm). Note: Punching does not usually occur in normal building. If bearing pressure on threaded parts is assumed for bolted connections or if oversize holes are used, the resulting deformations should be taken into account. (2) The design shear resistance of cross section through the threaded portion of a bolt of grade 6.8 should be determined from:


Fv.d '

F IRL SF UK

0,5 fub A s (Mb

Bolts of grade 6.8 are not specifically stated in Table 6.5.3. It should be noted that the load-carrying capacity expressions for bearing pressure also apply when the threaded portion of the bolt passes through the hole. If the shear strength of the bolted connection is based on the cross section of the shank, this should be stated in the Project Specification (see 7.5.3). (11) The values of Table 6.5.4 are based on a value of the partial factor of (Mb = 1,25. (8) Without a conclusive experimental justification, the first condition shall also apply to grade 8.8 bolts. (1) and (6) In the absence of Reference Standard 3 “Design resistance for bolts”, standards referred to in BS 5950–2 should apply. (9) The end distance should be determined in the direction of the force resultant applied. The edge distance should be determined in the perpendicular direction to the force resultant applied. The values for bearing resistance given in Table 6.5.3 of EC3: Part 1.1 may result in larger deformations joints than those normally accepted in the UK. Unless such deformation is acceptable, the bearing stresses on the parent material should be limited to 0,85 (fu + fy) / (Mb.

6.5.6

Design resistance of rivets

B SF

(1) The design resistance values stated in this Clause relate only to rivets in conformity with Reference Standard 5 of Annex B. (4) The end distance should be determined in the direction of the force resultant applied. The edge distance should be determined in the perpendicular direction to the force resultant applied.

6.5.7

Countersunk bolts and rivets

IRL

(2) In the absence of Reference Standard 3 “Angle and depth of countersink”, BS 4933 may be used.

6.5.8

High strength bolts in slip-resistance connections

6.5.8.1 Slip resistance B

(3) The values of (Ms to be used are as follows: (Ms.ult = 1,25 and (Ms.ser = 1,25 68


D DK

(4) The use of oversize or slotted holes in connections of load-bearing members requires the approval of the building inspectorate. (3) The ‘boxed values’ of partial factors for slip resistance should be: (Ms.ult

=

1,56

(Ms.ser

=

1,10

(4) The ‘boxed values’ of partial factors for slip resistance when oversize holes or slotted holes are used should be: (Ms.ult F

S


SF UK

=

1,72

(3) The values of (Ms to use are as follows: (Ms.ult = 1,10 and (Ms.ser = 1,20 (4) In these particular cases of connections, the following value shall be used: (Ms.ult = 1,25 (3) and (4) The factor (Ms.ser shall be put equal to 1,0 and (Ms.ult to 1,1(n with (n according to BKR 94, 2:115. (1) Only bolts of strength grades 8.8 or 10.9 are allowed in slipresistant connections. (3) The load combination for the serviceability limit state should be taken as the rare combination defined in 2.3.4(2) of EC3: Part 1.1.

6.5.8.2 Preloading D IRL

NL UK

The design preloading forces Fp,Cd are to be taken from column 2 of Table 1 of DIN 18 800 Part 7. (1) In the absence of Reference Standard 3 “High strength bolts”, standards referred to in BS 5950–2 apply. Also, in the absence of Reference Standard 8 “Tightening of high strength bolts”, BS 4604 applies. In (1), replace the reference by Reference Standard 8. For high strength bolts conforming to BS 4395–1:1969 and BS 4395– 2: 1969, with controlled tightening in conformity with BS 4604–1:1970 and BS 4604–2:1970, the design pre-loading force, Fp.Cd, to be used in design calculations should be that given in BS 4604–1:1970 and BS 4604–2:1970.

6.5.8.3 Slip factor B

IRL NL

(3) It is necessary to ensure that the required surface treatment retains its properties until the moment of assembly. If a surface protection of class A is required, a zinc-based product should be applied, and its behaviour must be demonstrated from the results of tests. The product used must have been recognised as valid. (1) to (3) BS 4604 shall be used in the absence of Reference Standard 8 “Slip factor for surface treatments”. In (1), (2) and (3), replace the reference by Reference Standard 8.

69


SF

(3) It shall be taken into account that the sand or steel grains may become rounded with use so that the aimed slip factor is not achieved in practice.

6.5.8.4 Combined tension and shear B UK 6.5.10

Long joints

B

(2) Another example is the distribution of shear forces in the web of a deep beam, near a joint made using bolted angle cleats.

6.5.12

Fasteners through packings

D

This Subclause contains the design rules for judging the indirect splice overlapping. (1) DS 412, paragraph 6.4.6 should be used for fasteners through packings. The design rule specified in ENV 1993–1–1:1992 paragraph 6.5.12 leads to evident absurdities if applied directly.

DK Created on 30 March 2011 This material is copyright - all rights reserved. Use of this document is subject to the terms and conditions of the Steelbiz Licence Agreement

(1) When tension and shear are combined, the preloading force Fp is not reduced by the whole of the externally applied tensile force Ft. Fasteners conforming to BS 4395–2:1969 should not be subjected to externally applied tension.

6.5.13

Pin connections

6.5.13.1 Scope DK

The requirements in the following should be met if the function of the connection demands that it is to rotate freely in the ultimate limit state, i.e. when subjected to the design force Nsd. If the free rotation is relevant only for small actions, the connection may be taken as a bolted connection with one bolt.

6.5.13.2 Pin holes and pin plates F

(1) This Clause must be considered as an Application Rule, not as a Principle.

6.5.13.3 Design of pins F

(1) This Clause must be considered as an Application Rule, not as a Principle.

6.6

Welded connections

D S

See also 3.3.5. As an alternative, BSK 94, 6:3 may be used. (3) For welding of quenched and tempered steels in bridges, BRO 94, 52.25 also applies.

70


6.6.1

General

B

The cross-sectional weld shapes mentioned in the Table are the most common. Some other shapes are given as an example in Figure 6.6 of the NAD. (2) Welding processes. prEN 24 063 “Welding, brazing, soldering and braze welding of metals – nomenclature of processes and reference numbers for symbolic representation and drawings” (ISO 4063:1990) is applicable. ENV 1993–1–3 Eurocode 3: Part 1–3 is in preparation, so apply 7.5 of DASt Ri 016 “Design and construction of structures of thin wall cold formed members”. The entire contents of paragraph 2.4 Welds of Part Two of D.M 14 Feb 1992 should be added to this section. Further indications regarding the choice of weld material and precautions to avoid the cracking in the thermally treated area or in the weld may be found in points 2.5.1 and 9.9.4 of CNR 1001/85. Further indications regarding the qualifying tests for welding procedures may be found in point 2.5.2 of CNR 10011/85. Further indications for classifying welds, regarding the extent of nondestructive controls and the acceptability criteria for defects, may be found in point 2.5.3 of CNR 19911/85. (2) Procedure 136 should be modified as follows: 136 – flux cored wire metal arc welding (with inert or active gas shield). Replace (2) with: Paragraph 6.6 is applicable for weldable constructional steel according to paragraph 3.2.

D


I

NL

6.6.2

Geometry and dimensions

6.6.2.1 Type of weld D

(1) to (4) and Table 6.6.1. The following types of weld require building inspectorate approval for use in load-bearing elements: flare groove welds in rectangular structural hollow sections and plug welds. Stud welding: DIN V ENV 1993–1–1 does not currently have any rules for stud welding. Therefore, element 835 of DIN 18 800 Part 1, November 1990 edition, is applicable.

6.6.2.2 Fillet welds B

F

I NL

(4) and (5) These provisions are not valid. (8) For elements subject to compression, the risk of local buckling should be checked. (11) The length L0 is defined in Figure 6.6.1. (12) A tensile force should be considered as significant if it exceeds 10% of the resistance of the plate subject to tension. (14) This Clause relates only to the case of Figure 6.6.2(c) in which the force to be transmitted must not be significant. (4) This paragraph must be considered mandatory for welds that are highly stressed and/or subject to significant fatigue or to atmospheric or other corrosion (thus not an Application Rule but a Principle). The things mentioned under (5) are cancelled. 71


6.6.2.3 Slot welds B

For fillet welds in round or elongated holes, the weld length is considered as the length of the hole. The diagram given in Figure 6.7 of the NAD specifies what is meant by this weld type.

6.6.2.5 Plug welds B D I

For plug welds in round or elongated holes, the hole should be completely filled with weld. Figure 6.8 in the NAD specifies what is intended by this type of weld. See also 6.6.2.1. This type of weld should not be used (point 9.2.4 of CNR 10011/85) especially in areas of tensile stresses and/or subject to fatigue.

6.6.2.6 Flare groove welds


B D DK I

(1) The throat thickness of flare grooves cannot be considered as greater than the width of the heat-affected zone, measured from the start of the external face of the profile (see Figures 6.6.3 and 6.6.4). See also 6.6.2.1. The effective weld section of flare groove welds in connections of square hollow sections and connections of solid round bars should be verified by preliminary procedural testing. This type of weld should not be used (point 9.2.4 of CNR 10011/85) for joints under heavy tensile stress and/or subject to fatigue.

6.6.3

Lamellar tearing

D

(1) to (3) DASt Ri 014 “Recommendations for avoiding lamellar tearing in welded constructions made of structural steel” may be used for assessing the risk of lamellar tearing. The requirements of DS 412, paragraph 6.1.7 should be met. PrEN 1011 Annex G gives more detailed guidelines for counteracting lamellar tearing.

DK

6.6.4

Distribution of forces

B F

(7) This application rule is not valid. (6) This Clause relates only to the connections subject to stresses greater than 75% of their design resistance in the case of a plastic global analysis. This requirement is explained by the fact that in a statically indeterminate structure, there is always some uncertainty about the distribution of internal forces and moments over this structure, and it is therefore necessary to provide also for a rotation capacity near the connections where, in theory, no plastic hinge may occur according to the calculation and design at the ultimate limit state. (7) The welds should be designed for the full design resistance of the weakest element, not 80% of the design resistance.

UK

72


6.6.5

Design resistance of a fillet weld

6.6.5.1 Effective length F

I SF

(1) The weld can have its full thickness at ends only if special care is taken during the welding. As a general rule, the actual length of the weld shall be reduced by the lengths of the beginning and of the undercut of the weld, this reduction being contractually taken as twice the effective throat a. (1) The effective length shall be assumed equal to the real length of the fillet, provided its end returns are not lacking or defective. (5) This applies to long overlapping joints. (1) The design length of a fillet weld R is the length of the weld designed into (i.e. shown on) the drawing including end returns.

6.6.5.2 Throat thickness F


I

SF UK

(4) A close visual checking of the geometry of the weld, more particularly as concerns collapse, is required within the application of this Clause. (4) Should be replaced with the following text: The effective throat thickness should be increased by 50% of the minimum penetration determined on at least three macrographs, derived from certification tests of the procedure or from specific test joints (at least one joint with a length > 500 mm; three macrographs derived one at the mid-point and two at 50 mm from the ends. (5) The calculated throat thickness shall be given in the drawings, irrespective of the welding method. The throat thickness should not be taken as more than 0,7 times the leg length (see Figure 6.6.6 of EC3: Part 1.1).

6.6.5.3 Resistance per unit length B DK

(5) This application rule can be modified in the following manner: The following value for the correlation factor $w should be adopted: (A Table is given in the NAD.] (4) If the approximated design method specified in 6.6.5.3 is used, the design shear strength of a fillet weld should be determined as fvw.d =

NL

0,9 f u $w (Mw 3

The design of fillet welds may be performed as specified in 6.6.5.3 or Annex M. The approximated design method specified in 6.6.5.3 may give results that are somewhat on the safe side. Welds in accordance with ENV 1993–1–1:1992 are generally based on a quality that more or less corresponds to weld class B in DS 412. The factor of 0,9 has been introduced to compensate for removal of the weld factors in DS 412. Replace (5) by: The correlation factor $w for different steel grades is given in Table 34 of NEN 6770: 1991.

73


6.6.6

Design resistance of butt welds

6.6.6.1 Full penetration butt welds I

Add the following two paragraphs: (2) (Mw = 1,05 must be used for class I joints and (Mw = 1,20 for class II joints. (3) Joints indicated by the designer as full penetration may be downclassed to partial penetration as one of the corrective actions, which must be approved by the designer and project manager, when controls reveal a lack of penetration. In any case, the controls must exclude the presence of defects exceeding the limitations of class II, other than lack of penetration. The throat thickness of the fillets (i.e. the thickness of the weld ligaments either side of the gap remaining due to lack of penetration), following downclassing, may be determined on the basis of nondestructive tests (ultrasound) or semi-destructive tests (end macrography or grinder probing) or edge preparation.

6.6.6.2 Partial penetration butt welds


DK I

(4) The penetration depth (weld cross section) in partial U and J joints may be put equal to the nominal depth of the joint without verification by preliminary procedural testing. Eliminate Figure 6.6.8. Replace paragraph 4 with the following: When using end preparations for partial penetration indicated in UNI 11001, the throat thickness can be considered equal to the depth of preparation. For other preparations, and whenever the penetration must be considered, the criterion set forth in paragraph 3 of 6.6.5.2 shall be used.

6.6.6.3 Tee-butt joints DK

I

A(3) In tee-butt joints with partial penetration butt welds with J-joints, the penetration depth (weld cross section) may be put equal to the nominal depth of the joints without verification by preliminary procedural testing. (1) The extent of penetration gap is established as follows: – equal to the shoulder using the preparations for partial penetration as set forth in UNI 11001 (point 9.2.5) – equal to the shoulder less 50% of the penetration, when this is to be considered, and whenever preparations other than those set forth in UNI 11001 are used (the criteria for evaluating the penetration are those of paragraph 3 of 6.6.5.2 of EC3, as amended in the NAD). The joints shall undergo ultrasound testing, with the criteria for class II joints; an unwelded gap of 3 mm is allowed; no unwelded gaps are permitted at the root. For resistance tests, (Mw = 1,20 is used, as with class II full penetration butt welds. (2) Replace (2) with the following: The resistance of a tee-butt joint that does not meet the requirements given in (1) must be determined as for a fillet weld. The throat thickness shall be considered equal to: 74


the theoretical value, using the preparations for partial penetration specified in UNI 11001 (point 9.2.5) – the value determined by macrographic sections, with the criteria specified in paragraph 3 of 6.6.5.2 (in the case of preparations other than those prescribed in UNI 11001, and whenever the penetration must be considered). Partial penetration butt-welded joints with preparation on only one side are tested like fillet welds, regardless of the extent of non-penetration. Tee-butt joint with partial penetration may be calculated like a full penetration butt joint (the nominal non-penetration cnom is indicated by applying the prescriptions of paragraph 1 of 6.6.6.3). Figure 6.6.9 should be modified as shown in the NAD. (3) Replace (3) with the following: Full penetration tee-butt joints shall be evaluated with the same criteria indicated for full penetration butt joints (point 6.6.6.1).


–

6.6.7

Design resistance of plug welds

D

This Subclause shall not be used.

6.6.8

Joints to unstiffened flanges

B

(3) The condition beff # 0,7b shall be applied only within a plastic analysis of the structure. (2) The effective breadth may also be calculated from :

F

beff = tw + 2r + C tf where C = 2,4

tf f y tp f yp

% 1,5 (

bf fy t p fyp

)0,5

The upper limit imposed on beff in this Clause is invalidated and replaced with both following conditions: – the resistance for the effective breadth shall not exceed the resistance of the flange subject to local bending, i.e.: beff # (t w %2r) % 7

tf 2

fy

tp

f yp

–

this resistance shall not exceed the resistance of the web of the member subject to local tension (or compression) to which a certain bending of the flange contributes (different from that previously mentioned). On this subject, Annex J may be referred to (see J.2.3.2 and J.2.4.1). (3) The condition beff # 0,7b shall be applied only within a plastic analysis of the structure. (4) The upper limit imposed on beff in this Clause is invalidated. The effective breadth beff in the case of a box section shall comply with: b eff # 2tw % 5

SF UK

tf 2

fy

tp

fyp

(3) The joint shall be stiffened when beff is less than 0,7 times the full breadth of the plate unless otherwise proved. (5) With regard to connecting welds, 6.6.8(5) in EC3: Part 1.1 assumes that the axial force, Nsd, in the plate is equal to its resistance, based on 75



its effective breadth, beff. In practice, where the axial force is less than this resistance, the welds should have a design resistance per unit length equal to Nsd / b eff, provided that the same size of weld extends across the full width of the plate. 6.6.9

Long joints

B

(3) The length Lj is illustrated in Figure 6.9 of the NAD. (4) This paragraph should be removed.

6.7

Hybrid connections

B

In general, the deformation capacities of different types of joint are such that they reach their ultimate resistance for different deformations; therefore the design and the detailing must be carried out in such a way that one type of fastener is able to carry the total force. Nevertheless, when welds are combined with preloaded bolts (category C) that are tightened after welding, the ultimate resistance for each one is reached at comparable deformations, so these two types of connection can act together to carry the whole of the applied force. Where two different fastening elements are used, if at least one of the two types has the deformation capacity necessary for the two elements to reach their ultimate resistance (for the same deformation), they can be considered together in order to determine the connection resistance. A few examples of hybrid connections corresponding to these conditions are given in Figure 6.10 of this NAD. This is equally valid for the strengthening of a joint by another means than the original method, provided that the second means is more rigid than the first. In this case, the strengthening supports the forces added afterwards. If different forms of fastener are used in the same connection or splice, compatibility of the deformation shall be ensured. Sharing of the load may be assumed in the case of – rivets and fitted bolts or – GVP fasteners and welds or – welds in one or both chords and rivets or fitted bolts in all other cross-section parts if the principal stresses are through bending moments My. The limiting internal forces result in these cases from the addition of the limiting internal forces of the individual fasteners. SL and SLV connections shall not be used with SLP, SLVP, GVP and weld connections for sharing the load.

D

6.8

Splices

6.8.1

General

B

(2) Provision means that the elements connected must be held in place and more specifically that the resistance and stiffness characteristics of the cover plates must be taken into account to determine the distribution of forces in the structure.

76



Discuss me ...

6.8.2

Splices in compression members

B

(1) When the sections of the connected members do not have the same properties, the characteristics of the weaker member must be taken into account in the application of the rules given below. (2) If in a joint, the forces (in compression) are transmitted by direct contact between the members via intermediate distribution plates, these must be machined to the necessary tolerances. The tolerances mentioned in the document prEN 1090–1: 1993, Clause 10.4.8, are to be applied: (a) the maximum angle between elements in contact: 1 in 1000 (b) maximum separation between the elements: – local: 1 mm – on two levels of surface contact: 0,5 mm (c) when the separation goes beyond these limiting values, but less than 6 mm, packs may be used to bring it within allowable limits.

6.8.3

Splices in tension members

B

(1) When the sections of the connected members do not have the same properties, the characteristics of the weaker member must be considered for the application of the rules given below.

6.9.1

Basis

B

(2) Several moment-rotation curves can be considered for modelling the behaviour of a beam-to-column connection [see 6.9.2(4)]. However, the choice of a particular curve may impose certain requirements with respect to the analysis of the structure and the design of its members. For instance, if the connection is semi-rigid and has partial strength, the analysis of the structure is of necessity elastic-plastic (see Table 5.2.1). When the distribution of forces in the structure is based on a first- or second-order calculation model, account must be taken, in the scheme, of the rotational stiffness of the beam-to-column connections. The determination of this stiffness is given in 6.9.7.2. If the calculation model is first-order plastic, account must be taken of the ultimate moment of the joints. The ultimate moment is determined following the indications given in 6.9.7.1. On the other hand, if a plastic second-order model is adopted, account must be taken of the rotational stiffness and the ultimate moment of the joints (see 6.9.7.1 and 6.9.7.2).

6.9.2

Moment-rotation characteristic

B F

Figure 6.9.2 should be replaced by Figure 6.11 of the NAD. (4) The moment resistance MRd shall be considered as having a fixed value when a bi- or tri-linear approximation is used. In consequence of amendment to 6.9.2(4), Figure 6.9.2 must be replaced by the Figure 6.9.2 in the NAD.

77


6.9.3

Moment resistance

B

Attention is drawn to the fact that Msd is determined by the calculation (see 6.9.7.1).

6.9.4

Rotational stiffness

B

Incremental calculation procedures mean the use of a model with material and geometrical non-linearity. Figure 6.9.5 should be replaced by Figure 6.12 of the NAD. (2) The secant stiffness is defined by the level of the design moment MSd. (3) For some purposes of the elastic design, such as the determination of the critical loading, it is necessary to define the initial rotational stiffness of a semi-rigid connection. This stiffness may be taken as the secant stiffness calculated for a design moment equal to 2 / 3 of the design moment resistance MRd. Figure 6.9.5 Rotational stiffness Sj: The moment resistance MRd shall be considered as having a fixed value when a bi- or tri-linear approximation is used. In consequence, Figure 6.9.5 must be replaced with a Figure that is shown in the NAD.


F

6.9.5

Rotation capacity

B F

Figure 6.9.7 should be replaced by Figure 6.13, given in the NAD. (1) Clause 1 must be replaced with: The design rotation capacity NCd shall be taken as the maximum rotation that the connection may be subject to without its moment resistance becoming less than MRd. Due to the replacement of Clause 1 in 6.9.5, Figure 6.9.7 is to replaced with a Figure shown in this NAD.

6.9.6

Classification of beam-to-column connections

6.9.6.2 Rotational stiffness B F

SF

(3) In this case, the condition for moment resistance defined in 6.9.6.3(2) ought to be satisfied. (3) In this case, the moment resistance requirement defined in 6.9.6.3(2) shall also be met (5) The condition on Kb / Kc is intended to limit the load capacity loss of the structure, due to the P-) effect in direct relation with the choice of the straight line m ¯ = 25 N ¯ on Figure 6.9.8(a). (7) A joint classified as rigid or nominally pinned cannot be treated as semi-rigid.

6.9.6.3 Moment resistance B F

(2) In this case, the stiffness condition defined in 6.9.6.2(3) also ought to be satisfied. (2) In this case, the stiffness requirement defined in 6.9.6.2(3) shall also be met.

78


6.9.7

Calculated properties

6.9.7.1 Moment resistance B

F SF

(2)(a) Additional criteria: – plastification of the beam flange – tearing of the plate around the bolts. (2)(b) Additional criteria: – plastification of the beam web – yielding of the beam flange – local buckling of the beam flange. (2)(b) Any plastification or buckling in the compression zone of the beam (more particularly of the flange) shall also be a failure criterion. (2) The other possible failure modes shall also be checked.


6.9.7.3 Rotation capacity D

(1) For the tests, the following applies: test reports shall contain data on the aim of the test, the planning, apparatus, procedure and evaluation of the tests in a form that permits evaluation and also independent repetition of the tests.

6.9.8

Application rules

F

(3) Sections 7, 8 and 9 of French standard NF P 22–460 may be applied for the design of a bolted beam-to-column connection. This standard has its own consistency, and it shall not be allowed to refer only to some specifications or formulae of Annex J.

6.10

Hollow section lattice girder joints

S

The whole Clause applies as advisory notes.

6.10.1

Design resistance

F

(2) The requirement of a redistribution of secondary bending moments shall be considered only when these moments are not explicitly taken into account in the connection resistance formulae.

6.10.2

Application rules

F

(2) French standards NF P 22–250, NF P 22–251, P 22–252, NF P 22–255 and NF P 22–258 may be applied. They implicitly assume that the internal forces and moments in the connections are calculated through an elastic analysis of the structure within the assumption of a full restraint of the lacing members on the chords. In addition, their field of application is limited to the case of plane girders. However, the resistance formulae of these standards relate to the same failure criteria as those stated in 6.10.1(1) and have been adjusted, as far as safety is concerned, mostly with the same experimental data as those of Annex KK. In other respects, these have their own consistency, and it shall not be allowed to refer only partly to some specifications or formulae of 79



Annex KK. Within this French standard context, the partial factor (Mj of the connections shall be taken as 1. In addition, the welds of the lacing members onto a chord shall be designed and checked according to the specifications of standard NF P 22–470. 6.11

Column bases

S

The whole Clause applies as advisory notes.

6.11.1

Base plates

SF

(1) A base plate can be omitted providing the forces can reliably be distributed on the foundation.

6.11.2

Holding down bolts

F

(2) This Clause relevant to the lever arm shall apply only within a plastic distribution of the forces in the holding down bolts, and of the stresses in the contact area of the base plate with the foundation. (4) When the shear force between the column and the foundation is taken up by shear in the holding down bolts, the risk of concrete rupture due to bearing forces should also be checked.

6.11.3

Application rules

D

(1) The rules of Annex L are informative.

7

FABRICATION AND ERECTION

CH

This Section is only valid in an informative sense. It describes the minimum requirements for fabrication and erection only insofar as the assumptions for design and dimensioning according to ENV 1993 are fulfilled. If the conditions for fabrication and erection laid down in SIA 161 and 161/1 are complied with, the requirements for the use of Eurocode 3 are also fulfilled. In view of current Italian legislation, Chapter 7 “Prove statiche” (Static Testing) in Part Two of M.D. 2 Feb 1992 should be entirely transcribed and applied. This prescription does not replace point 7.8 Inspection and Testing. Replace Chapter. The entire Section shall be replaced by BSK 94, 8 and 9. For bridges BRO 94, 55 and 56 shall in addition apply. For railway bridges, BV BRO, 550, 551 and 555.3 shall in addition apply.

I

NL S

7.1.1

Scope

F

(3) This Clause is not applicable in this paragraph. transferred, substantially, into 7.2.

80

It must be


7.1.2

Requirements

F

All the contents of this paragraph must be conveyed into 7.2, which is the right place. (1) Standards referred to in BS 5950–2 shall be used in the absence of Reference Standards 6, 7, 8 and 9. (1) The Reference Standards 6–9 mean the Prestandard SFS–ENV 1090–1: The execution of steel structures, Part 1: General rules and rules for buildings. The principal rules and application rules presented in the Prestandard SFS–ENV 1993–1:1992 and the rules presented in the Prestandard SFS–ENV 1090–1 as well as the requirements presented in the project specification shall be taken into account in the execution of buildings.

IRL


SF

7.2

Project specification

F

Clauses of paragraph 7.2 contain some relational aspects. We propose the following Clauses: (1) The Project Specification shall include the minimum requirements stated in paragraphs 7.3 to 7.7. (2) The requirements of the Project Specification shall not be below the minimum requirements of this Section. (3) The minimum Project requirements shall be specified in terms of the reference standards stated in Annex B. (4) The specific requirements for special structures shall be included in the Project Specification. (5) As much as possible, the special requirements of the Project Specification shall be stated in accordance with the reference standards. (7) Standards referred to in the Project Specification to be consistent with design may be used in the absence of those listed in Eurocode 3.

IRL 7.3

Fabrication restrictions

F

Paragraph 7.3 is replaced by: (1) The use of hardened material shall be avoided or forbidden in some cases, and suitable provisions shall be made. This hardening may be due to strain or quenching. As concerns the limitations of use, refer to: – Reference Standard 6, as a general rule – Section 9, when fatigue is a limit state to be considered – the restrictions that shall be defined in the Project Specification, in special cases. (3) Standards referred to in BS 5950 may be used in the absence of Reference Standard 1 “Supply conditions” in Eurocode 3.

IRL 7.5

Bolted connections

7.5.1

Holes

F

Clauses 3 and 4 are to deleted in the expectation of the specific European standards. (19) The use of a flame in processing holes is always excluded.

I

81


7.5.2

Clearance in holes for fasteners

D

(5)–(12) Oversize and slotted holes are not permitted for slip-resistance connections. (1) Holes for fitted bolts should be performed in accordance with DS 412, paragraph 7.3.3. Clause 4 to be replaced with: The clearances for fitted bolts shall in no case exceed 0,3 mm. (4) BS 5950–2 applies in the absence of Reference Standard 6 “Clearance for fitted bolts” listed in Eurocode 3.

DK F IRL 7.5.3

Bolts

DK

(2) If the shear strength of bolted connections is based on the shank area of the bolts, this should be specified in the construction specifications.

7.5.6

Tightening of bolts

I

(4) To check the tightening of preloaded bolts, apply point 6.10.2 of Part Two of M.D. 14 Feb 1992. (3) BS 4604 applies in the absence of Reference Standard 8 “Tightening of preloaded bolts” listed in Eurocode 3.


IRL 7.5.7

Slip resistant contact surfaces

I

The indication of point 6.10.2 of Part Two of M.D. 14 Feb 1992, regarding the procedure for preparing contact surfaces, should be added to paragraph 1.

7.6

Welded connections

D

The following is applicable for welding in cold formed areas: If welding is carried out in cold formed areas including the adjacent areas of width 5t, the limiting values min r/t as shown in Table R6, contained within the NAD, shall be adhered to. Linear interpolation may be used for values between those in lines 1 to 5. The strain values given in Table R6 need not be adhered to if cold formed parts are normalised prior to welding. The indication in points 6.5 and 6.10.3 of Part Two of M.D. 14 Feb 1992 must be added to this paragraph. Further specifications are provided in point 9.2 of CNR 10011/85 (regarding the practical rules of designing and executing welded connections) and in point 9.3.2 of CNR 10011/85 (regarding practical rules for designing and executing welded beams).

I

7.7.4

Fabrication tolerances

F

(1) Until the publication of the European Prestandard about the construction of steel structures falling within the competence of the Technical Committee (CEN TC/135), the project Specification shall provide all the needed requirements, in conformity with the design rules, and, as far as possible, drawn from the latest version of this Prestandard.

82


IRL SF

7.8

Inspection and testing

DK

The quality requirement for control of finished welds in statically loaded structures is the same as applies to weld class B in DS 412. (1) and (2) BS 5950–2 applies in the absence of the Relevant Reference ‘standards, inspection and testing’, listed in Eurocode 3.

IRL


(1) BS 5950–2 applies in the absence of Reference Standard 6 “Tolerances”, listed in Eurocode 3. When the straightness tolerance of a member exceeds the values given in Table 7.2, the member shall be straightened or the resistance of the member shall be verified by calculations or experimentally taking the measured value of the deviation into account.

8

DESIGN ASSISTED BY TESTING

D NL

According to building inspectorate requirements, the application of design values of the resistance variable Rd determined by tests requires the approval of the chief building inspectorate authorities. Replace Chapter 8 with: For the verification to the requirements, use may be made of testing under the condition that the test results are interpreted judiciously and the requirements of 7.2 of NEN 6700: 1991 are satisfied.

8.1

Basis

DK

Experimental verification of load-carrying capacity should only be used for verification or calibration of a theoretical model of the construction detail considered. The following general rules should be included in the basis of the tests: (1) A theoretical model should always be available. The test results are only to be used for calibration of this model (through selected parameters) and, in case of systematic inconsistencies, they should give rise to revision of the model. (2) The test series should form a statistically significant basis for calibration of the theoretical model. (3) The results should be statistically prepared to ensure attainment of the same true safety level as by usual design verification (see DS 412, Sections 8.6 and 8.7). (4) The test series should be well documented and controlled to allow verification of the results at a later date.

8.2

Planning of tests

IRL

(4) In the absence of Annex Y, BS 5950–1 applies.

8.4

Test evaluation

D IRL S

(2) Annex Z is in preparation. (2) In the absence of Annex Z, BS 5950–1 applies. (2) Reference to Annex Z can be replaced by Boverkets (Board’s) handbook Dimensionering genom provning (Design by testing). 83


8.5

Documentation

F

The documentation may more particularly include comments on all the incidents that occurred during the tests. It may also possibly include an interpretation of the results.

9

FATIGUE

B

Figure 9.1.1 should be replaced by a Figure intended to appear in the NAD but omitted. In Figure 9.1.2, between ND and NL, m takes the value 5. This Section is only valid in an informative sense. The fatigue safety still has to be verified according to SIA 161, because in Eurocode 3 important rules, e.g. service load factors ", have not been fixed to cover all cases. This Clause contains general rules for verifying the strength of structures made of steel not subject to static loading. The fatigue strength values given here may be used in conjunction with DIN 4132 for designing crane runways if the requirements of Annex C of this guideline are taken into account. Replace Chapter 9 with: Fatigue values must be verified according to 5.2.3 in NEN 6770: 1991.

CH

D


NL 9.1

General

9.1.2

Scope

UK

For crane supporting structures, reference should be made to BS 2573–1:1983, BS 466:1984, BS 2573–2:1980 and the crane manufacturer’s publications for loading and frequency details.

9.1.3

Limitations

F

(1) Clause 1 is invalidated and replaced with: For fatigue assessment, all nominal stresses [see 9.1.5(7)] shall be within the elastic limits of the material. The maximum variation range of the nominal stresses, considering all rare combinations relating to the serviceability limit states [see 2.3.4(2)], shall not exceed 1,5 fy for nominal stresses or 1,5 fy / o3 for shear stresses.

9.1.4

Necessity for fatigue assessment

F

(1)(a) For want of a fatigue load code compatible with this Eurocode format, the fatigue assessment of crane gantry girders is not covered by this French experimental standard. (2) Clause 2 is invalidated, requirement (a) is cancelled and requirements (b) and (c) are modified as follows: No fatigue assessment is required when any of the following conditions is satisfied: equations 9.2 and 9.3 from the NAD state these conditions.

84


9.1.5

Definitions

DK

(12) In Figure 9.1.1 “Design spectrum”, the designations of the coordinate axes Number of cycles N and Applied stress range )F are interchanged. A(13) in this NAD provides the equivalent constant stress range. Further reference is made to paragraph 9.5.2.2.

9.2

Fatigue loading

F

(1) Until publication of Eurocode 1, the following documents shall be applicable for fatigue loadings in the relevant building structures: (a) Crane gantry girders: see amendment to 9.1.4(1)(a) (b) Other loadings: Project Specification. Fatigue loading from overhead travelling cranes shall be determined according to BSK 94, 3:432. The load spectra given there shall be replaced by an equivalent number of constant amplitude load cycles according to the table given in the NAD. For oscillations caused by vortex shedding N can be put equal to 107 or according to Boverket’s handbook “Snow and wind load”. For road bridges, a load spectrum in accordance with BRO 94, 21.2226 shall be applied. For railway bridges, the load spectrum in BV BRO shall be replaced by the following equivalent number of load cycles of constant amplitude.


S

9.3.1

General

B

(2) The note is replaced by: In-service inspection is a condition of applying the minimum (Mf given in Table 9.3.1. In-service inspection means: a visual inspection that can detect cracks and which is carried out at time intervals corresponding to 10% of the total number of cycles predicted by the calculation. In the absence of in-service inspection, a partial factor (Mf with a value greater than that given in Table 9.3.1 should be applied. In-service inspection is not a requirement of ENV 1993–1–1 Eurocode 3: Part 1.1, but can be considered as a design assumption that must be acknowledged by the project manager and/or the user of the structure. In Table 9.3.1, lower values of partial factor for loads are chosen than in ENV 1993–1–1. The main reason is to keep the approximately same level of reliability of member against fatigue damage because: – the fatigue strength is lower in ENV 1993–1–1 than in existing Czech Standard CSN 73 1401 for the same detail category – differentiation of partial factors according to maintenance conditions was not used in CSN till now. (2) Clause 2 is invalidated because the note it includes is not applicable. Clause 2 is therefore replaced with: Inspection may detect fatigue cracks before subsequent damage is caused. Such inspection is visual unless otherwise specified in the Project Specification.

CZ

F

9.3.2

Partial factors for fatigue loading

IRL

(3) In the absence of ENV 1991, apply the principles of 9.3.2. 85



Discuss me ...

S

(4) The factor (Ff shall be put equal to 1,0. For road bridges, R( according to BRO Table 22–1 applies and for railway bridges BV BRO Table 2.2.2–1 applies.

9.3.4

Recommended value of

B

(1) Add: As long as there is no adequate Reference Standard 9, it shall be a requirement that welded construction should satisfy level B (higher demand) of permitted defects in NBN–EN 25817 (Connections in arcwelded steel – Guide of acceptance levels for defects). The fabrication drawings shall mention explicitly that welds must satisfy this level B and shall specify particular execution requirements corresponding to the types of details used (see columns ‘description’ and ‘requirement’ in Tables 9.8.1 to 9.8.7). Add: The distinction between ‘fail-safe’ components and non ‘fail-safe’ components must not be based solely on the consequences of collapse of the structure but more generally from the point of view of stability, safety and the use of the structure. Example: A crack in a diagonal of the surge girder of a crane beam in a steel works. The crane beam does not necessarily collapse but the steel works suffers a stoppage. (3) Table 9.3.1 is invalidated and replaced by Table 9.3.1 given in the NAD. (1) Reference is made to the application rules for paragraph 9.6.1, A(7). (2) and (3) The sections should be replaced by DS 412, paragraph 5.2.3. The value of the partial factor of the fatigue strength in the ultimate limit

DK

(Mf

state should be (Mf = 1,56 . F

IRL S

SF

(1) Until publication of Reference Standard 9, Standard NF P 22–471 shall be applied to the relevant building structures. The constructional details shall meet the quality requirements relevant to quality class 2 as stated in Table 5 of this Standard (visual inspection). (3) Table 9.3.1 is invalidated and replaced with Table 9.3.1bis (given in the NAD). Recommended values of the partial factor (Mf are given in Table 9.3.1bis. (4) This Clause is invalidated because the values of (Mf stated in Table 9.3.1 have been determined to be valid whatever the values of (Ff fixed in other respects. (1) Apply BS 5950–2 in the absence of Reference Standard 9 “Quality assurance for fatigue”. (4) The factor (Mf shall be put equal to 1,1(n for structural details that are difficult to access for inspection and equal to (n in other cases. Partial factor (n according to BKR 94, 2:115. Periodic inspection is presupposed. (3) The partial factors for the material are defined in Table 1 of the NAD.

86


9.5

Fatigue assessment procedures

9.5.2

Fatigue assessment based on nominal stress ranges

B

Add: If necessary, the notion of nominal stresses in this paragraph should be replaced by the notion of modified nominal stresses. In addition these stresses must take account of the effects mentioned in 9.4.2 (2).


9.5.2.2 Variable amplitude loading F

(2) Clause 2 is invalidated with reference to Clause 9.1.4(2) and replaced with: If the application of Clause 9.1.4(2) condition (c) does require a fatigue assessment, this shall be carried out through one of the following procedures: – cumulative damage, see (3) – equivalent constant amplitude, see (7).

9.6.1

General

B

(7) Add: As long as there is no adequate Reference Standard 9, it shall be a requirement that welded construction should satisfy level B (higher demand) of permitted defects in NBN–EN 25817 (Connections in arcwelded steel – Guide of acceptance levels for defects). A(7) Fatigue loaded welds in accordance with ENV 1993–1–1:1992 are based on a quality more or less corresponding to weld class C in DS 412. Deviation from this quality requirement is permissible if it can be documented that the deviation is structurally sound. (7) Until publication of Reference Standard 9, Standard NF P 22–471 shall be referred to, on the basis of quality class 2 such as defined in Table 5 of that Standard. (7) In the absence of Reference Standard 9 “Acceptable discontinuities”, apply BS 5135 with amendment AMD 5712.

DK

F IRL 9.6.3

Fatigue strength curves for non-classified details

B

(2)(a): Provided that level B of NBN–EN 25817 is met, it may be assumed that the criterion for acceptable weld defects is satisfied. Also, for category 90, the acceptance criterion for weld profile is as indicated in the Figure in the NAD. (2)(a) For case (a), until the publication of Reference Standard 9, the weld defect acceptance criteria are given [see 9.3.4(1)] in Table 5 Standard NF P 22–471, on the basis of quality class 2. In addition, for category 90, the weld profile acceptance criterion is given on the Figure shown in the NAD.

F

9.8

Classification tables

DK

For references to Reference Standard 9 in Tables 9.8.3, 9.8.5 and 9.8.6, the application rules for paragraph 9.6.1, A(7) apply. 87


S

The whole Clause applies as advisory notes. The values given presuppose welding class WB. (1) Detail factors according to BSK 94, Appendix 2 may be used.

Table 9.6.4 B

Note: The columns headed ‘Verticals’ do not make sense for K type joints.

Table 9.6.5 B

Note: The columns headed ‘Verticals’ do not make sense for K type joints.

Table 9.8.1 Sheet 2/2, Joint 8 B

Note: The value of the detail category should be changed from 36 to 50.

Table 9.8.1 Sheet 2/2, Joint 9


B

Note: The value of the detail category is also valid for fitted bolts of classes lower than grade 8.8.

Table 9.8.3 Sheet 1/2, Joints 1 and 2 B

Note: Provided that level B of NBN–EN 25817 is met, joints 1 and 2 may be promoted to detail category 125.

Table 9.8.4 Sheet 1/2, constructional detail 1 B

Add: The connection is required to be welded throughout its length.


Note: The detail category value can be taken as 90 whatever the thickness.


Note: Provided that level B of NBN–EN 25817 is met, it may be assumed that the required condition is satisfied.

Table 9.8.5, Category 71 IRL

In the absence of Reference Standard 9 “Discontinuities”, apply BS 5135 with amendment AMD 5712.

Table 9.8.6 IRL

In the absence of Reference Standard 9 “Defects”, apply BS 5135 with amendment AMD 5712.

88


Table 9.8.6 Sheet 1/2, constructional details 1, 2 and 3 B

Note: Provided that level B of NBN–EN 25817 is met, it may be assumed that the required condition (quality level 3 of Reference Standard 9) is satisfied.

Table 9.8.6 Sheet 2/2, constructional details 6 and 7 B

Note: Provided that level B of NBN–EN 25817 is met, it may be assumed that the required condition (quality level 3 of Reference Standard 9) is satisfied.

Table 9.8.6 Sheet 2/2, constructional details 8 and 9 B

Note: The figures should be corrected: they really apply to fillet welds.

ANNEXES CH

The annexes are to be considered as supplementary to ENV 1993–1–1, in order to aid design and dimensioning in individual cases.


ANNEX B

REFERENCE STANDARDS (NORMATIVE)

D SF

See 0.5.3 of DIN V ENV 1993–1–1 and Annex A of this guideline. The reference standards to be used in conjunction with the NAD are presented in Tables 2 to 10 (see also Appendix 1) of the NAD.

B.1

Scope

DK

P(1) In the period until the European standards specified in the following are finished as EN or ENV, the relevant current Danish standards should be used, or, if such standards are not available, other corresponding, relevant national standards may be used. A(1) German, British and Swedish standards may be considered relevant, and the connection between EN and DIN/BS/SIS standards can be seen from the German, English and Swedish NAD. The standards prEN or prENV specified in B.2 will not be applicable until they are approved, but after approval they are mandatory.

B.2

Definitions

DK

To facilitate the use, a Table has been set up for each Reference Standard, specifying the proposed European Standard and, if possible, the corresponding Danish Standard that is to be used until approval of the European standard. These tables are given in the NAD.

B.2.1

Reference standard 1: Weldable structural steel

NL

Replace B.2.1 with: The construction standards should be verified according to 7.1 of NEN 6770: 1991.

89



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B.2.2

Reference standard 2: Dimensions of sections and plates

NL

B.2.2 to be replaced.

B.2.3

Tolerances

NL

B.2.3 replaced with 7.4 of NEN 6770: 1991.

B.2.4

Reference standard 3: Bolts, nuts and washers

NL

B.2.4 replaced with 7.2.2 of NEN 6770: 1991.

B.2.5

Reference standard 4: Welding consumables

NL

B.2.5 replaced with 7.2.2 of NEN 6770: 1991.

B.2.6

Reference standard 5: Rivets

NL

B.2.6 replaced with Chapter 7 of NEN 6772: 1991.

B.2.7

Reference standard 6 to 9: Process standards

NL


B.2.8

Reference standard 10: Corrosion protection

NL


ANNEX C CZ

D NL S

DESIGN AGAINST BRITTLE FRACTURE (INFORMATIVE)

The calculation procedure and values for brittle fracture limit state according to Annex C are not recommended because they give unrealistic results that overestimate the resistance to brittle fracture. The main reason is in low value (depth) of fictitious crack a = ln(t), especially for thicker materials. t (mm)

10

25

50

75

100

150

200

250

ln t

2.3

3.2

3.9

4.3

4.6

5.0

5.3

5.5

Deeper defects exist in practice in the Czech Republic. The required fracture toughness K1c, obtained from equation C.2, is therefore not sufficient. DASt Ri 009 “Recommendations for the selection of steel quality groups for welded steel structures” may also be used. Annex C to be replaced. Annex C applies as advisory notes. The values of F shall be calculated using the design values of loads, and in Classes S1–S3 the limiting values of F shall be multiplied by 1,2. The factor (c shall be put equal to (n.

90


C.2

Calculation procedure

C.2.3

Consequences of failure

SF

The class C2 is generally used in buildings.

C.2.4

Nominal yield strength

SF

(2) The term ‘lower’ is unnecessary in this context.

C.2.5

Parameters

DK

(1) The ‘boxed values’ of the partial factor (C should be: (C = 1,0 for C1


(C = 2,24 for C2 C.2.6

Calculations

DK

(2) Formula C.3 should be changed to Tmin = Tcv % 12 % $ % (83 & 0,08f yl)(kd)0,17

ANNEX E D

BUCKLING LENGTH OF A COMPRESSION MEMBER

S

The following supplementary literature is applicable: Web openings, Annex N of ENV 1993–1–1 has not been published, so use Clause 5 of DASt Ri 015 “Beams with thin webs”. Shell buckling, Part 4 of ENV 1993 has not been published, use DIN 18 800 Part 4. Annex E applies as advisory notes.

E.1

Basis

SF

Increased values of buckling lengths should be used when the boundary conditions presented in Annex E are not reliably achievable.

ANNEX F D

S

Concerning high strength steels, Annex D of ENV 1993–1–1 has not been published. The steels permitted by IfBt and DASt Ri 011 “High strength weldable fine-grain structural steels StE 460 and StE 690, application for steel structures” are applicable. Annex F applies as advisory notes.

ANNEX J D S SF

LATERAL-TORSIONAL BUCKLING

BEAM TO COLUMN CONNECTIONS (NORMATIVE)

Further methods may be used. Annex J applies as advisory notes. This NAD does not cover Annex J. Annex J has been revised and was accepted as an ENV in autumn 1994, after the publication of this NAD. 91


ANNEX K K.1

General

D DK

Annex K replaces and expands the rules in DIN 18 808. A(8) The value of the partial factor (Mj for the resistance of joints should in the Annex be taken as (Mj = 1,28. Annex K applies as advisory notes. The factor (Mj shall be put equal to (n. This NAD does not cover Annex K. Annex K has been revised and accepted as an ENV in June 1993.

S SF K.5

Welds

NL

Replace (4) with 11.6.1 of NEN 6772: 1991.

ANNEX L


HOLLOW SECTION LATTICE GIRDER CONNECTIONS

DESIGN OF COLUMN BASES (NORMATIVE)

D S

Annex L is not normative but informative. Annex L applies as advisory notes.

L.1

Base plates

DK

It should be noted that application of this Annex gives conservative dimensions of column bases in relation to Danish current practice. In (6) the design value of the concrete cylinder compressive strength fcd shall be taken as the characteristic value of the concrete compressive strength according to 6.1.1 of NEN 6720: 1991. The thickness of the base plate should not be less than the thickness of the column flange that it supports. When calculating the bearing strength, fj, of the joint, the (c factor should be taken as 1.5.

NL UK

L.2

Holding-down bolts

F

(3) This Clause relevant to the lever arm shall apply within a plastic distribution of the forces in the holding-down bolts, and of the stresses in the contact area of the base plate with the foundation. (6) The anchorage length of holding down bolts has to be taken in accordance with 9.16 of NEN 6720: 1991.

NL

ANNEX M ALTERNATIVE (NORMATIVE) DK S

NL S

FOR

FILLET WELDS

The amendment for two of the equations is given in the NAD. Annex M applies as advisory notes.

ANNEX Y D

METHOD

GUIDELINES FOR LOADING TESTS (INFORMATIVE)

According to building inspectorate regulations, application of these requires the approval of the chief building inspectorate authorities. Annex Y to be replaced. Annex Y applies as advisory notes. 92



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Y.1

General

D

(4) Reference to ENV 1993–1–3 Eurocode 3: Part 1–3 is in preparation. (5) Reference to ENV 1994–1–1 Eurocode 4: Part 1–1 is available in English. The German version (DIN V ENV 1994 Part 1–1) is in preparation.

Y.3

General test procedures

F

(2) Clause 2 is invalidated and replaced with: Prior to any test, preliminary loading, not exceeding 30% of the characteristic values of the relevant loads, may be applied and then removed in order to bed down the test specimen onto the test rig. (7) In order to allow this comparison, all geometrical dimensions of the test specimen shall also be measured.

Y.4.1

Acceptance tests

F

(3) Clause 3 is invalidated and replaced with: The test load for an acceptance test shall be: 1,0 x (actual self-weight of the tested structure or element) 1,0 x (remainder of the loads), and 1,0 x (variable loads). (4)(a) The global behaviour shall be elastic up to the test loading. This behaviour is linear as a general rule, but not always so. (4)(b) Clause 4(b) is invalidated and replaced with: On removal of the test load, the residual displacement shall not exceed 10% of the maximum value recorded during the test. (5) Clause 5 is invalidated and replaced with: If the conditions given in (4) are not satisfied, the loading may be applied a second time. The test specimen shall demonstrate elastic behaviour under this second application of the test loading, and the new residual displacement shall not exceed 5% of the maximum value recorded during this second test. (3) The acceptance test in accordance with section Y.4.1 alone is not sufficient for the experimental design of a structure.

SF Y.4.2

Strength test

F

(7) Formula Y.1 is invalidated and replaced with equation Y.1 contained in the NAD.

Y.4.3

Test to failure

D F

(9) Annex Z is in preparation. Clauses 10 to 14 are invalidated and replaced with Clauses 10 and 11 hereafter: (10) When the deviation from the mean does not exceed 10%, the design resistance shall be determined from Clause 11 hereafter. (11) The design resistance Frd shall be determined from the behaviour of the test specimen during the test. Once the type of behaviour curve linking a force with a characteristic displacement of the test specimen has been selected, the behaviour curve achieved shall be related to one of the 93



four (case of members) or three (case of connections) shapes of previously defined experimental behaviour curves. – In the case of members (Figure 1, shown in the NAD), the evolution from shape 1 towards shape 4 is ductile-type failures to brittle type failures. – In the case of connections (Figure 2, shown in the NAD), the evolution from shape 1 towards shape 3 is from elements with a high rotation capacity to elements with a low rotation capacity. Design resistance assessment formulae along with equations Y.2, Y.3 and Y.4 are given in the NAD. Y.4.5

Testing to determine strength functions and model factors

D

(2) Annex Z is in preparation.

94


4

EUROCODE 4

4.1

Boxed values

4.1.1 Partial factors (F for actions General Partial factors for actions are summarised in Table 4.1. For Denmark, the values from standard DS409 are to be used. The ‘boxed values’ are generally the same as the indicative values given in the ENV, apart from Denmark, but the following changes should be noted: Permanent actions in accidental situations The UK and the Czech Republic distinguish between favourable and unfavourable effects.


Actions in persistent and transient design situations The factors specified in the Dutch NAD depend upon a safety classification according to the loading code NEN 6702. Imposed deformations The French NAD classifies imposed deformations as ‘permanent’ and ‘variable’ and Clause 2.3.3.1(4) of the ENV is superseded by values given in the NAD [see 2.3.3.1(4)I and Table 1 in the additional Appendix to Chapter 2].

4.1.2 Combination factors Ri These factors were not specified in ENV 1994–1–1. Instead, reference was made to Eurocode 1 or other relevant loading codes or to the client [Clause 2.2.2.3(4)]. Considerable variation in the values, and in the form of presentation, occurs between the NADs. For this reason, no comparative tables are presented for Ri values and reference should be made to the NADs themselves. The values chosen have been influenced in some cases by the national loadings to be used and existing national values for partial factors. In other cases they have been influenced by the values in different drafts of ENV 1991–1 available at the date the NAD was issued. Clause 2.3.3.1(6) and 2.3.4(5) provide simplified rules for combinations of actions on building structures. These avoid use of the Ri factors specified in the NADs.

4.1.3 Partial factors (M for resistances Partial factors for resistances are summarised in Table 4.2. Structural steel Two values of (a for structural steel apply in France. The lower value of 1,0 can only be used if the material is marked ‘NF Acier’ [see French NAD Clause 2.3.3.2(1)I]. 95


Concrete and reinforcement Two values of (c for concrete and (s for reinforcement apply in Finland, according to the class for structural concrete. The classification system is explained in Section 2 “Basis of Design” in the Finnish NAD. Shrinkage of concrete The indicative values have been changed in the French NAD. Increase of bending resistance due to normal force, Clause 4.8.3.13(6) The reduction in the safety factor for the favourable component NSd has been increased to 30% in the UK NADs. Design resistance from tests on composite slabs, Clause 10.3.2.5 The reduction factors are listed in Table 4.2 as the inverse of the partial factor. Values have been changed in the Danish and German NADs.


4.2

Clauses in ENV 1994–1–1 referenced by National Application Documents

The Clauses of ENV 1994–1–1 referenced by the NADs are shown in Table 4.3. The details of the references are given in Section 4.3.

4.3

Comparison of National Application Document requirements

The details of the NAD requirements are listed below in ascending order of ENV 1994–1–1 Section numbers, with the abbreviations for the relevant country, as listed in Section 2. In most cases the text given is that in the relevant NAD (or in an English translation of the NAD). Text from the NADs is sometimes only quoted in part, omitting introductory phrases, etc., and in other cases unclear English has been clarified. In a few instances, comments have been made by the authors. Text following a paragraph number, e.g. “(3) A value is given for ...”, is generally additional to the text of ENV 1994–1–1, except where noted otherwise. No distinction is usually made between Principles and Application Rules.

96

Table 4.1

Partial factors (F for actions in NADs for EC4

Reference in EC4

Action

Symbol

EC4

(GA

1,00

Favourable

(G.inf

Unfavourable


B

DK

SF

F

D

GR

IS

IRL

I

L

NL

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

0,90

1,00

1,00

1,00

(G.sup

1,35

1,40

1,20

1,35

1,35

Favourable

(Q.inf

0,00

0,00

0,00

0,00

Unfavourable

(Q.sup

1,50

1,40

1,50

(QA

1,00

Favourable

(G.inf

Unfavourable Both parts

N

P

E

S

CH

UK

CZ

1,00

0,90 or 1,05

0,90 or 1,00

0,9

1,00

1,00

1,00

1,35

1,20 or 1,35

1,35

1,35

1,20

0,00

0,00

0,00

0,00

0,00

0,00

1,50

1,50

1,50

1,20 to 1,50

1,50

1,50

1,40

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,10

1,10

1,10

1,10

1,10

1,10

1,10

1,10

1,10

(G.sup

1,35

1,35

1,35

1,35

1,35

1,35

1,35

1,35

1,20

(G.inf

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

2.3.2.2(3) Permanent Accidental situation

2.3.3.1(1) Permanent

97

Variable

2.3.3.1(2) Variable Accidental situation 2.3.3.1(3) Permanent (2 parts)


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Table 4.2 Reference in EC4 2.3.3.2

Partial factors (M for resistances Resistance

Symbol

EC4

Fundamental

(a

1,10

Accidental

(a

Fundamental

Accidental

Partial factors (M specified in NAD A

B

DK

SF

F

D

GR

IS

IRL

I

L

NL

1,00

1,28

1,10

1,00*

1,10

1,10

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

(c

1,50

1,50

1,80

1,35 or 1,50

1,50

1,50

(c

1,30

1,00

1,00

1,00

1,15

Fundamental

(s

1,15

1,15

1,40

1,10 or 1,20

Accidental

(s

1,00

1,00

1,00

Fundamental

(ap

1,10

1,10

Accidental

(ap

1,00

1,00

N

P

E

S

CH

UK

CZ

1,10

1,10

1,05

1,15

1,00

1,00

1,00

1,05

1,00

1,50

1,50

1,50

1,50

1,50

1,50

1,30

1,30

1,20

1,30

1,30

1,30

1,30

1,15

1,15

1,15

1,15

1,15

1,15

1,15

1,15

1,00

1,00

1,00

1,00

1,15

1,00

1,00

1,00

1,00

1,28

1,10

1,10

1,10

1,10

1,00

1,10

1,10

1,05

1,15

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,05

1,00

Structural steel

Concrete

98

Reinforcement

Profiled steel sheet

Note: *In the case of the French NAD, (a = 1,00 if the steel products used benefit from the mark ‘NF Acier’, but (a = 1,10 for other cases.


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Table 4.2 continued Reference in EC4

Resistance

Partial factors (M for resistances Symbol

EC4

Fundamental

(Rd

1,10

Accidental

(Rd

4.8.3.5

Flexural stiffness of concrete

6.3.2.1

Partial factors (M specified in NAD DK

SF

F

D

1,10

1,28

1,10

1,10

1,10

1,10

1,00

1,00

1,00

1,00

1,00

1,00

1,00

1,00

(c

1,35

1,35

1,62

1,35

1,35

1,35

Shear studs

(v

1,25

1,25

1,50

1,25

1,25

6.3.7

Angle connectors

(v

1,25

1,25

1,50

1,25

6.5

Friction grip bolts as connectors (v

1,25

1,25

1,50

1,00

1,00

1,00

4

A

B

GR

IS

IRL

I

L

NL

N

P

E

S

99

CH

UK

CZ

1,10

1,10

1,05

1,15

1,00

1,00

1,00

1,05

1,10

1,35

1,35

1,35

1,35

1,35

1,35

1,25

1,25

1,25

1,25

1,25

1,25

1,30

1,25

1,25

1,25

1,25

1,25

1,25

1,25

1,30

1,25

1,25

1,25

1,25

1,25

1,25

1,25

1,35

1,30

1,00

1,25

1,00

1,00

1,00

1,00

1,00

1,00

1,00

Buckling of structural steel

ULS SLS 7.6.1.3

Shear resistance in slabs

(vs

1,25

1,25

1,50

1,25

1,25

1,25

1,25

1,25

1,25

1,25

1,25

1,30

10.2.5

Test evaluation of shear connectors

(v

1,25

1,25

1,50

1,25

1,25

1,25

1,25

1,25

1,25

1,25

1,25

1,30

10.3.2.5

Design resistance of slabs

1/(

0,75 0,50 0,75

0,75 0,50 0,75

0,65 0,40 0,65

0,75 0,50 0,75

0,75 0,50 0,75

0,75 0,50 0,65

0,75 0,50 0,75

0,75 0,50 0,75

0,75 0,50 0,75

0,75 0,50 0,75

0,75 0,50 0,75

0,75 0,50 0,75

E

Shear resistance in slabs

(v

1,25

1,25

1,50

1,25

1,25

1,25

1,25

1,25

1,25

1,25

1,25

1,30


Discuss me ...


Table 4.3




B

DK

SF

F

D

X

X

X

X

100

1.1.1

Scope of Eurocode 4

1.1.2

Scope of Part 1.1 of Eurocode 4

1.2

Distinction between Principles and Application Rules

X

1.3

Assumptions

X

1.4.2

Special terms used in this Part 1.1 of Eurocode 4

X

1.6.4

Greek lower case letters

X

Chapter 2

Basis of design

X

X

2.1


X

X

2.2.1.1

Limit states

2.2.1.2

Design situations

2.2.2.1

Definitions and principal classification (of actions)

X

X


GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

X

X

X

X X

X

X

X X X

CZ


Discuss me ...


Table 4.3 continued



101

2.2.2.2

Characteristic values of actions

2.2.2.3

Representative values of variable actions

2.2.2.4

Design values of actions

2.2.3

Material properties

2.2.5


2.3.2.2

Combinations of actions

2.3.2.4

Verification of static equilibrium

2.3.3.1

Additional information relating to partial safety factors for actions on building structures

2.3.3.2

2.3.4

Additional information relating to partial safety factors for resistances and material properties Serviceability limit states


B

DK

SF

F

D

GR

IS

IRL

I

L

NL

X

X

X

X

X

X

X

X

X

N

P

E

S

CH

UK

CZ

X

X X X

X

X

X

X

X

X

X

X

X

X

X


X

X

X

X

X


Discuss me ...


Table 4.3 continued




B

DK

SF

F

3.1.1

General (concrete)

3.1.2

Concrete strength classes

3.1.3

Shrinkage of concrete

X

3.1.4.1

Secant modulus of elasticity (of concrete) for short-term loading

X

D

GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

X X

X

102

3.2

Reinforcing steel

X

3.2.1

General

X

3.2.2

Types of steels

X

3.2.3

Steel grades

3.2.4

Modulus of longitudinal deformation

X

3.2.5

Stress-strain diagram

X

3.3

Structural steel

X

3.3.1

General and scope

3.3.2

Yield strength

3.3.4

Stress-strain relationship

X

X

X X

X

X X

X


X X

X

CZ


Discuss me ...


Table 4.3 continued




B

DK

SF

F

D

103

3.3.5


3.4

Profiled steel sheeting for composite slabs

3.4.1

General and scope

X

3.4.2

Yield strength

X

3.4.5

Coating

X

3.5.1

General (connecting devices)

3.5.2

Shear connectors

X

X

4.1.1

General

X

X

4.1.2

Beams

X

X

4.2.1

Effective section (of beams)

X

4.2.2

Effective width of concrete flange for beams

X

4.2.2.1

Effective width for global analysis

X

4.2.2.2

Effective width for verification of cross sections

X

X

GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

X

X

X X

X X

X


X

X

CZ


Discuss me ...


Table 4.3 continued




B

DK

SF

F

104

4.2.3

Flexural stiffness

4.3

Classification of cross sections of beams

4.3.1

General

X

4.3.2

Classification of steel flanges in compression

X

4.3.3.2

Sections where the compression flange is in Class 3 or Class 4

X

4.4.1.4

Elastic resistance to bending

4.4.2.2

Design methods (for vertical shear)

4.4.3

Bending and vertical shear

4.4.4


4.4.5

Interaction between bending and shear buckling

4.5.1

General (internal forces and moments in continuous beams)

4.5.2.2

D

GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

CZ

X X

X

X

X

X X

X

X

X

X

X

X

X

Requirements for rigid-plastic analysis


X

X

X


Discuss me ...


Table 4.3 continued




B

DK

SF

F

D

GR

IS

IRL

I

L

NL

105

4.5.3.4

Redistribution of moments in beams

X

4.6.1

General (lateral-torsional buckling of composite beams)

X

4.6.2

Check without direct calculation

X

X

4.6.3

Buckling resistance moment

X

X

4.7

Web crippling

4.7.1

General

4.8

Composite columns

4.8.1

Scope

X

4.8.2.2

Design procedures

X

X

4.8.2.3

Imperfections

X

X

4.8.2.5

Cover and reinforcement

X

X

4.8.2.6

Shear between the steel and concrete components

X

X

4.8.2.7

Resistance to shear

X

4.8.3

Simplified design

X

N

P

E

S

CH

UK

CZ

X X X

X


X

X

X


Discuss me ...


Table 4.3 continued




B

DK

SF

F

D

GR

IS

IRL

I

L

NL

106

4.8.3.1

Scope

X

4.8.3.2

Additional information relating to partial safety factors (Ma, (a and (Rd

X

X

4.8.3.3

Resistance of cross sections to axial loads

X

X

4.8.3.5

Effective elastic flexural stiffness of cross sections

X

4.8.3.6

Buckling lengths of a column

4.8.3.7

Relative slenderness

4.8.3.9

Combined compression and bending

4.8.3.12

Influence of shear forces

4.8.3.13

Resistance of members in combined compression and uniaxial bending

4.9.1

General (internal forces and moments in frames)

4.9.2.1

Basis

N

P

E

S

CH

UK

X X

X

X X X

X


X

X

X

X X

X

CZ


Discuss me ...


Table 4.3 continued




B

DK

SF

F

D

GR

IS

IRL

I

L

NL

107

4.9.2.2

Simple framing

4.9.5

Methods of global analysis

X

4.9.6.2

Flexural stiffness

X

4.9.7.1

General (rigid plastic global analysis)

X

4.10.3.1

General (connections made with bolts, rivets or pins)

4.10.3.2


4.10.5.4

Classification of momentrotation characteristics

Chapter 5


5.1

General

X

X

5.2.1

General (deformations)

X

X

X

X

5.2.2

Calculation of maximum deflections of beams

X

X

X

5.3.1

General (cracking of concrete in beams)

X

X

X

N

P

E

S

CH

UK

CZ

X

X X

X X X


X X


Discuss me ...


Table 4.3 continued


Reference in EC4 Clause Number and Title 5.3.2

Minimum reinforcement

5.3.4

Control of cracking due to direct loading, without calculation of crack widths


B

DK

SF

X

F

D

GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

CZ

X X

X

108

Chapter 6

Shear connection in beams

6.1.2

Deformation capacity of shear connectors

X

6.1.3

Spacing of shear connectors

X

6.2.1.3

Partial shear connection with non-ductile connectors

X

6.2.2

Beams in which elastic theory is used for resistances of one or more cross sections

X

X

X

6.3.2.1

Headed studs – shear resistance

6.3.3.2

Sheeting with ribs transverse to beams

6.3.3.3

Biaxial loading of shear connectors

X

6.3.5

Anchors and hoops

X


X

X

X X


Discuss me ...


Table 4.3 continued




B

DK

SF

F

109

6.3.6

Block connectors

6.3.7

Angle connectors

6.4.1

General (detailing of the shear connection)

6.4.1.2

Cover and compaction of concrete

6.4.2

Stud connectors

X

6.4.5

Anchors and hoops

X

6.5.2.1

Design friction resistance (friction grip bolts)

X

6.5.3

Serviceability limit state

X

6.5.4

Detailing of friction grip bolts

6.6.1

Longitudinal shear in the slab

6.6.2

Design resistance to longitudinal shear

D

GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

X X X X

X

X X

X X


X

X

CZ


Discuss me ...


Table 4.3 continued




B

DK

SF

F

110

7.1

General (composite slabs with profiled steel sheeting)

X

7.1.1

Scope

X

7.2.1

Slab thickness and reinforcement

X

7.2.3

Bearing requirements

7.3.2.1

X

D

GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

X

X

X

Profiled steel sheet as shuttering (Actions)

X

X

X

7.3.2.2

Composite slab (Actions)

X

7.3.3

Load combinations and load cases

X

7.4.1

Profiled steel sheet as shuttering (Analysis)

X

X

X

7.4.2.1

Analysis (of composite slab)

X

7.4.2.2

Effective width for concentrated loads

X

7.5.1

Ultimate limit state (sheeting as shuttering)

7.5.2



X

X X

X

CZ


Discuss me ...


Table 4.3 continued



Partial factors (F specified in NAD

111

F

D

7.6.1.2

Flexure (composite slabs)

A

B

DK

SF

X

X

GR

IS

IRL

I

L

NL

7.6.1.3

Longitudinal shear without end anchorage

X

X

7.6.1.4

Longitudinal shear with end anchorage

X

7.6.1.5

Vertical shear

X

7.6.1.6

Punching shear

7.6.2.2

Deflection

X

X

8.1

General (floors with precast concrete slabs)

X

X

8.2

Actions

8.3

Additional information relating to partial safety factors

X

8.4.1

Support arrangements

X

8.4.2

Joints between precast elements

8.4.3

Interfaces

8.5.1

Bedding and tolerances

X X

X

X


X

X X

X X X

N

P

E

S

CH

UK

CZ


Discuss me ...


Table 4.3 continued




B

DK

SF

F

112

8.6

Concrete floor designed for horizontal loading

Chapter 9

Execution

9.1

General (execution)

9.2

Sequence of construction

X

9.4

Accuracy during construction and quality control

X

9.4.1

Static deflection

X

9.4.3.1

Headed studs

X

9.4.3.2

Anchors, hoops, block connectors

9.4.3.3

Friction grip bolts

X

9.4.3.4

Corrosion protection

X

9.4.4

Composite slabs

9.4.4.1

Fixing of sheets

9.4.4.3

Loads

9.4.4.4

Stud connectors welded through sheeting

D

GR

IS

IRL

I

L

NL

N

P

E

S

CH

X X X


X

X X

X

X

X X X X

UK

CZ


Discuss me ...


Table 4.3 continued




B

DK

SF

F

113

9.4.4.5

End anchorages

X

9.4.4.6

Additional Clause

X

Chapter 10

Design assisted by testing

10.1

General

X

10.2.1

General (tests on shear connectors)

X

10.2.4

Testing procedure

X

10.2.5

Test evaluation

X

10.3

Testing of composite floor slabs

X

10.3.1.2

Testing arrangement

10.3.1.3

Preparation of specimens

10.3.1.4

Test loading procedure

10.3.1.5

Determination of design values for m and k

10.3.2.5

Determination of the design resistance


D

GR

IS

IRL

I

L

NL

X

X X X

X X

P

E

S

CH

UK

CZ

X

X

X

N


Discuss me ...


Table 4.3 continued




B

DK

SF

F

114

A.2

Standards on materials and products

A.2.1

Standards mentioned in EC2

A.3

Reference documents for execution

X

A.4

General standards

X

B.1.1

Simplified method for calculation of slenderness ratio

X

D

GR

IS

IRL

I

L

NL

N

P

E

S

CH

UK

X X

B.1.2

Elastic critical moment

X

B.1.4

Mono-symmetrical steel sections

C.1

Scope and assumptions

C.2

Compressive resistances

C.4

Bending resistances

C.6.2

Major axis bending of encased I sections

X

C.6.3

Minor axis bending of encased I sections

X

C.6.4

Hollow sections

X


X X X X X

CZ


Discuss me ...


Table 4.3 continued




B

DK

SF

F

D

115

D.4

Compression and uniaxial bending

D.5

Long term behaviour of concrete

E.2

Determination of Ju.Rd

X

E.3

Verification of longitudinal shear resistance

X

E.4

Verification of slabs with end anchorage

E.5

Verification of slabs with additional reinforcement

X

IS

IRL

I

L

NL

N

P

E

S

CH

UK X

X

X


GR

X X

X

CZ


Discuss me ...



1.

INTRODUCTION

1.1.1

Scope of Eurocode 4

D

(4) ENV 1998 Eurocode 8 is not available. DIN 4149 Part 1 and DIN 4149 Part 1A should be used. (5) ENV 1991 Eurocode 1 is not available. The rules of DIN 1055 should be used. (3) The reference to Eurocodes 2 and 3 must include references to the corresponding NADs, i.e. the following standards: – NF P 18–711 – Eurocode 2 “Design of concrete structures” and NAD – Part 1.1: General rules and rules for buildings – NF P 22–311 – Eurocode 3 “Design of steel structures” and NAD – Part 1.1: “General rules and rules for buildings” unless otherwise indicated in the text. (4) In view of the current stage in drafting Eurocode 8, one must apply French standards, i.e: – NF P 06–013 “Rules for earthquake resistant construction – PS rules applicable to buildings”, called PS 92 rules – Chapter 13. (6) For the design of composite slabs with profiled steel sheeting for buildings, use of the following is permitted: – “Technical Advice” formulated by the Specialist Group No. 3 of the Commission of Technical Advice whose secretaryship is held by the CSTB, or – Eurocode 4 – DAN 1.1. In each case, the entire chosen text must be applied. (3) In the absence of Eurocodes 2 and 3, the documents IS/ENV 1992 and IS/ENV 1993 should be used instead. (5) In the absence of Eurocode 1, the documents BS 6399–1 “Code of practice for dead and imposed loads” with Amendment Slip No. 1 AMD 4949 and BS CP3 Chapter V, Loading, Part 2: “Wind loads” with Amendment Slips No. 1: AMD 4952, No. 2: AMD 5152 and No. 3: 5343 should be used. (1) ENV 1994–1–1 together with the accessory NAD may be assumed to be equal to NEN 6700 for the intended scope. (5) Eurocode 1 must be read as NEN 6702.


F

IRL

NL

1.1.2 D

SF

Scope of Part 1.1 of Eurocode 4 (6) ENV 1994–1–2 Eurocode 4: Part 1–2 is not available at present. For the design of resistance to fire, DIN 4102 Part 4 and the application rules of the ‘communique´s’ 3/88 and 4/88 of the German Institute for Civil Engineering (DIBt) or certifications of accepted test Institutes are applicable. Where partial concrete encasement is taken into account for the resistance to bending and shear of composite beams, supplementary application rules are given in Chapters 4 and 5 of the NAD. (6) In this Section a list is given of the structures and design conditions, which are out of the scope of Prestandard ENV 1994–1–1, Part 1.1. According to it, composite beams of slim type, in which the steel member is partly or totally inside the depth of the concrete slab, and for which the behaviour of the shear connection is based on the ability of the

116



longitudinally cracked or non-cracked concrete to transfer shears, are out of the scope, and they shall not be designed according to ENV 1994–1–1:1992. 1.1.3

Further parts of Eurocode 4

NL

Include a Clause 1.1.4, which is given in the NAD.

1.3

Assumptions

D

For the determination of stresses for geotechnical design or stresses in structural members, which can not be designed in accordance with the safety concept of Eurocode 4, the safety concept of the relevant standards (e.g. DIN Standards) should be used. In this case the design values of internal forces and moments of the ultimate limit state should be divided by the most unfavourable partial safety factor but not smaller than (F = 1,35. This is also valid for the design of fire resistance, if the design method is based on stresses.

NL

In the NVN–ENV 1994–1–1 a number of numerical values is boxed. These so called ‘boxed values’ are given as an indication. Only changed ‘boxed values’ will be treated in the following text. For the other ‘boxed values’, the values given in the NVN–ENV 1994–1–1 should be used.

1.4.2

Special terms used in this Part 1.1 of Eurocode 4

D

S

Figures 6.9.2, 6.9.4, 6.9.5, 6.9.6 and 6.9.7 are replaced by Figures in the NAD, which correspond to figures in DIN V ENV 1993–1–1. (1) In Clause 7.1.2.2, shear connection is provided by mechanical shear connection. The whole Clause applies as advisory notes.

2

BASIS OF DESIGN

2.1


IRL

(2) The requirements of Clause 2.4.5 of BS 5950–1 may be used to meet these requirements. Add to this Clause 5.2 and 5.3 of NEN 6700. (2) Design rules to provide structural integrity by limiting the effects of accidental damage are given in Annex A of the NAD.

F

NL UK

2.2.1.2 Design situations UK

(2) Strength and stability should be checked for the construction stage where the steel beam acts non-compositely to support the permanent load of formwork and the imposed load of fresh concrete plus construction loads or temporary storage loads.

117


2.2.2.2 Characteristic values of actions D


F

The values given in the DIN Standards (especially in the Standards of series DIN 1055, and if necessary the relevant complementary documents and guidelines) should be used as characteristic values of actions. Characteristic values of actions that are not (or not completely) specified in standards or other requirements must be determined in agreement with the building control authorities. When calculating according to Eurocode 4: Part 1–1, with regard to DIN 1055, Part 4/08.86 (in connection with changes in A1 of 06.87 and with the printed list of errors), the following should be taken into account: – The last sentence in Clause 3.3 shall not be used; the note to Clause 3.3 remains valid – Clause 4 shall not be used. Note: Prestandard DIN V 1055 Part 40 (Wind loads) is not introduced by the relevant authorities. For DIN 1055 Part 5/06.75 (actions due to snow and ice), the following should be considered: – Clause 5 (combined action of wind and snow) should not be used. (5) Before the publication of ENV 1991 Eurocode 1, the current characteristic values of variable actions that should be used with this experimental standard are shown in the table below. It should be noted that the characteristic value of wind loading should be taken as equal to the value of ‘normal wind’ in DTU P 06–002 (NV65) multiplied by 1,2. For consistency with limits for horizontal deflections currently practised, an adjustment to the limits fixed by ENV 1994–1–1 Eurocode 4 for serviceability limit states is implemented. Variable actions considered

NL

Characteristic value of action

Service load

Value taken from the standard NF P 06–006

Snow load

Value taken from the standard DTU 06–006 (N84)

Wind load

1,2 times the ‘normal’ value, taken from the standard DTU 06.002 (NV65)

Temperature (if necessary)

Expansion: –4 x 10–4 to 3 x 10–4 [mm/mm] or differential: –40 to +30 (0C) in relation to the rise of temperature

Replace text by: The characteristic values of actions should be taken from Chapters 7, 8 and 9 of NEN 6702.

2.2.2.3 Representative values of variable actions CZ D F

Until the combination coefficients R from EC1 are available, the values from Table 2 of the NAD are at the disposal of practising engineers. A statistical approach is allowed if adequate data exist. (4) ENV 1991 Eurocode 1 is not available. Table R1 should be used. (4) Before the publication of ENV 1991, Eurocode 1, the values of the coefficients Ri that should be used with this experimental standard are given in a Table in the NAD. 118


NL

Replace text by: The factor Ri (i = 0, 1 or 2) must be taken equal to R, as described in Chapters 6, 8 and 9 of NEN 6702.

2.2.3

Material properties

CZ

The characteristic values of material properties of concrete, reinforcement and steel are according to ENV 1992–1–1 and ENV 1993–1–1. The characteristic strength for stud connectors is according to material code for stud steel from which the stud is produced.

2.2.5


D

See Clause 2.2.2.2.

2.3.2


D

Referring to Table 2.1, the factors R given in Table R1 of the NAD should be used.


2.3.2.2 Combinations of actions NL UK

Add: In fundamental combinations the extreme value of the uniformly distributed variable action Qk,1 must be multiplied by Rt, taking into account 5.1 and 5.5 of NEN 6702. When designing for the accidental situation in Table 2.1 of EC4: Part 1.1, the values of R1, R2 and Ak should be determined from Annex A and Table 3 of the NAD. The accidental load Ak (34 kN/m2; see A.4 of the NAD) should be multiplied by a (A factor of 1,05. The (GA factor should be taken as 1,05, except where the dead load is considered as consisting of unfavourable and favourable parts, in which case the favourable part should be multiplied by a (GA factor of 0,9 and the unfavourable part should be multiplied by a (GA factor of 1,05.

2.3.2.4 Verification of static equilibrium D

See NAD to EC3: Part 1–1, Clause 2.3.2.4.

2.3.3.1 Partial safety factors for actions on building structures F NL

(4) For the case of imposed permanent deflections, partial safety factors are given in Table 1 of this comparison document. Add to this Clause 5.1 and 5.2.2 of NEN 6702. Table 2.2 must be replaced by a Table given in the NAD.

2.3.3.2 Partial safety factors for resistances and material properties CZ

F NL

Partial safety factors for steel are about 10% lower than ENV ‘boxed values’ because of lower partial safety factors for actions. All factors are in Table 1 of the NAD. Safety factors for concrete and reinforcement are retained due to the unchanged calibration calculations. (1) The safety factors are given in Table 1 of this document. Table 2.3 must be replaced by a Table given in the NAD. 119


2.3.4


D

For verifications according to the equations 2.14 to 2.16, the factors R given in Table R1 of the NAD are to be used. In special cases a deviated factor R2 may be used, if the relevant authorities agree. Supplement: For accidental combinations the value of the uniformly distributed variable action Q may be multiplied with Rt, taking into account 5.1 and 5.5 of NEN 6702. For frequent combination the value of Q can be multiplied with the factor Rt = 0,6 in concrete creep calculations. Quasi-permanent combinations are considered equal to frequent combinations.


NL

3

MATERIALS

3.1

Concrete

3.1.1

General

F

(1) Within the scope of this Experimental Standard, the unit mass of unreinforced lightweight concrete must not be less than 1750 kg/m3.

3.1.2

Concrete strength classes

D

Reference should be made to Clause 3.1.2.2 of the NAD to EC2: Part 1-1.

3.1.3

Shrinkage of concrete

F

(2) Use the following values in place of those in EC4: 300 x 10–6 for normal weight concrete 450 x 10–6 for lightweight concrete (these values replace those in EC4). (2) It is advisable to consider the following regions as being representative of a dry environment: – Provence, Alpes, Cote D’azur – Languedoc, Roussillon – Rhone, Alpes – Corsica.

3.2

Reinforcing steel

D UK

Reference should be made to Clause 3.2 of the NAD to EC2: Part 1–1. Pending the issue of prEN 10080 as an EN, reference should be made to BS 4449:1988 (bars) and BS 4483:1985 (welded fabric) for the material properties of reinforcing steels. The differences between the British standards and the draft European Standard are summarised in 6.3a of the NAD to DD ENV 1992–1–1: 1992 (EC2: Part 1).

120


3.2.1

General

F

NL

In accordance with EC2 – DAN, before publication of the standard EN 10080, reference should be made to Section 4, Title 1 of CCTG (Journal of general technical clauses) “Reinforcing bars for concrete”. The three documents BS 4449 “Specification of carbon steel bars for the reinforcement of concrete”, BS4482 “Specification for cold reduced steel wire for the reinforcement of concrete” and BS 4483 “Steel fabric for the reinforcement of concrete” should be used in the absence of EN 10 080. Supplement: Clause 5.1.2 of NEN 6720 is applicable.

3.2.3

Steel grades

IRL

The three documents BS 4449 “Specification of carbon steel bars for the reinforcement of concrete”, BS4482 “Specification for cold reduced steel wire for the reinforcement of concrete” and BS 4483 “Steel fabric for the reinforcement of concrete” should be used in the absence of EN 10 080. (2) Delete the reference to EN 10 080 (in preparation). Also, the ‘national documents’ must be read as NEN 6008.

IRL


NL 3.3

Structural steel

D UK

As to the use of high-strength steel and as to the properties of materials for hot rolled and cold formed steel, reference should be made to the NAD to EC3. For materials properties of structural steels to be used in design calculations for composite steel and concrete structures, reference should be made to Clauses 5 and 6 of the NAD to DD ENV 1993–1–1:1992 (EC2: Part 1.1).

3.3.2

Yield strength

F

NL

(1) to (3) Paragraphs 1 to 3 including Table 3.3 are no longer valid. Reference should be made to reference standards of Annex BB of EC3 – DAN where information is given concerning nominal values of yield strength, fy, and tensile strength, fu. The nominal values of fy and fu for hot rolled structural members, as a function of the thickness of the element, are given in Figures shown in this NAD. Standards referred to in BS 5950 should be used in the absence of EN 10 025. EN 10 025 in (1) and (3) must be read as 9.1.2 of NEN 6770.

3.3.5


NL

Supplement: If the tolerances of a profiled steel sheeting are greater than the tolerances given in the following table, it should be proven by calculation or experimental evidence that the structure has the required reliability.

IRL

121


Tolerances for profiled steel sheeting (%)

Total depth sheeting Core thickness

+ve

Sve

4

–1

10

–5

Dimensions embossments Distance between embossments

5

–5

3.4

Profiled steel sheeting for composite slabs

UK

For additional guidance on the material properties of profiled steel sheeting for composite slabs, reference should be made to the NAD to EC3: Part 1.3.

3.4.1

General and scope

D

(3) Profiled steel sheeting may be used for composite floors only, if the production, the quality control and the resistance to longitudinal shear are arranged in national technical approvals. (1) This Part 1.1 of Eurocode 4 covers the design of composite slabs with galvanized profiled steel sheets, which conform to the standard prEN 10 147. (2) Within the scope of the design rules of this Eurocode, it is recommended that the chosen nominal thicknesses of the metal sheeting should not be less than 0,75 mm, in accordance with the standard EN 10143. The use of metal sheeting with a smaller thickness requires reference to particular rules defined within the scope of a European Technical Agreement. In the absence of reference standards that include tolerances on the embossments, the rules presented in EC4 – DAN 1.1 cover profiled steel sheeting where the height of embossment is not less than 90% of the nominal value and not greater than 120% of this value. (1) Standards referred to in BS 5950 or ISO 4997–1978 should be used in the absence of EN 10 025, prEN 10 113, ISO 4997–1978 and prEN 10 147. (1) EN 10 025 must be read as 7.1.2 of NEN 6770. The document prEN 10 113 must be read as 7.1.3 of NEN 6770. Delete the reference to prEN 10 147.

F Created on 30 March 2011 This material is copyright - all rights reserved. Use of this document is subject to the terms and conditions of the Steelbiz Licence Agreement

–10

IRL NL

3.4.2

Yield strength

F

(2) Table 3.4 is invalid. Only profiled steel sheeting that conforms to the standard EN 10147 is taken into account. (2) Standards referred to in BS 5950 or ISO 4997–1978 should be used in the absence of EN 10 025, prEN 10 113, ISO 4997–1978 and prEN 10 147. EN 10 025 in Table 3.4 must be read as 7.1.2 of NEN 6770. The document prEN 10 113 in Table 3.4 must be read as 7.1.3 of NEN 6770. Delete the reference to prEN 10 147 in Table 3.4.

IRL NL

122


3.4.5

Coating

F

(4) Coating other than by galvanizing should not be used for the protection from corrosion. Lacquering is authorised if used in addition to the galvanizing. (2) Standards referred to in BS 5950 should be used in the absence of ISO 4998–1977.

IRL 3.5

Connecting devices

3.5.1

General

D

(2)

3.5.2

Shear connectors

D

(6) Fabricated shear connectors shall be in accordance with national standards. For headed stud shear connectors, DIN 32500 Part 3 applies. (5) Less severe requirements can be applied to non-ductile shear connectors (Chapter 6). However, it is advisable to satisfy the limit fu / fy > 1,05 and a lengthening at point of fracture greater than 8%. (6) The material properties of shear connectors should be in accordance with the recommendations in 3.4 of BS 5950: Section 3.1: 1990.

F


UK

Reference should be made to Clause 3.3 of the NAD to EC3.

4

ULTIMATE LIMIT STATES

4.1

Basis

4.1.1

General

D F

(4) Concerning the material properties reference should be made to the NADs to Eurocodes 2 and 3. (8) For slender columns, Clause 4.8.3.5(2) is relevant. (9) Except for particular cases, the last two paragraphs should not be taken into account.

4.1.2

Beams

D

(2) For cross sections in class 1 or 2 where the web of the steel section is encased by reinforced concrete the contribution of which, to the resistance in bending and vertical shear may be taken into account. See Clauses 4.5.3 and 4.4.2.2 of this NAD. Until EC4: Part 1–2 is available for beams that have to be designed for fire resistance, a certification of an accepted Institute is required. (5) The second paragraph of Clause 4.1.2(5) is invalidated and replaced by the following: In tapering members, sections so chosen that the ratio of the greater to the lesser plastic moment of resistance (under bending stress of the same sign) for any pair of adjacent sections does not exceed 1,5. (3) The reinforcement A500HW according to Standard SFS 1215 complies with the rules for high ductility bars given in Section 3.2.4.2 of ENV 1992–1–1:

F

SF

123


guk > 5 % and (ft / fy)k > 1,08 where guk is the characteristic strain at peak stress ft, and fy is the characteristic yield strength. Reinforcement B500K according to Standard SFS 1257 does not fulfil the requirement guk > 5%. 4.2.1

Effective section

D

(3) With regard to the ductility of the reinforcement, reference is made to Table R2 of the NAD to EC2: Part 1–1.

4.2.2

Effective width of concrete flange for beams in buildings

SF

Where prefabricated slab elements are employed, the effective width of the concrete compression flange shall not be taken higher than 0,12 l0 on one side of the beam, if top concrete is employed as reinforced with respect to shearing off the compression flange. Where no reinforcement is employed, half of the value given for the reinforced case shall be applied at maximum.


4.2.2.1 Effective width for global analysis F

(1) The possibility offered by this Clause does not apply to global plastic analysis.

4.3

Classification of cross sections of beams

CH

The following table should be inserted to verify structural safety and requirements on cross sections. Calculation methods Verification of structural safety and requirements on cross sections Calculation Calculation of Determination method internal forces of sectional and moments resistances

CZ

Requirements on the cross sections In SIA 161 according to

In ENV 1994–1–1 cross sections of

PP

Plastic

Plastic

Table 15a

Class 1

EP

Elastic

Plastic

Table 15b

Class 2

EE

Elastic

Elastic

Table 3c

Class 3

EER

Elastic

Elastic reduced

Table 7

Class 4

Remark: For the verification of the structural safety, the cross sections are classified into classes according to their rotational capacity. The boundaries of the cross-section classes differ only slightly according to the latest findings from SIA 161. Cross-section classification is fully accepted to enable extensive use of plastic design.

4.3.1

General

IRL

(10) BS 5950–8 and EC4: Part 1.2 should be used in the absence of EC4: Part 1.2. (10) Eurocode 4: Part 1.2 must be read as NEN 6069.

NL

124


4.4

Resistance of cross sections of beams

CZ

The calculation of the cross-section resistance according to the elastic or plastic approach is possible. The plastic approach is more economical than the elastic approach. The partial shear connection between steel and concrete parts is allowed.

4.4.1

Bending moment

4.4.1.2 Plastic resistance moment of a section with full shear connection D

For cross sections in Class 1 or 2 with reinforced concrete encasement, the contribution of the concrete encasement and the reinforcement in bending may be taken into account, if full shear connection according to EC4: Part 1–1, Clause 4.1.2(6) and 6 is provided between the reinforced encasement and the steel section.

4.4.1.4 Elastic resistance to bending


F

NL SF

(3) The third paragraph of Clause 4.4.1.4(3) is invalid: for conformity with EC3 during the construction phase, it is replaced by: fy / (Rd in structural steel in compression or in tension in an effective cross section of Class 4, where (Rd = 1,10. (3) For Class 4 I sections or box sections, bent simply in the plane of the web(s), and for which the flanges are Class 1 or 2, it is allowable to adopt fy / (a instead of fy / (Rd as the flexural stress limit for structural steel, in compression or tension. This possibility is only admissible where the members concerned are not subject to other forms of instability [see Clause 5.4.5.2(1)A of EC3 – DAN]. (3) The ‘boxed value’ 1,10 must be replaced by the value 1,0. Where no propping is applied to the steel member, and the bending resistance Mel.Rd is not calculated directly, the verification of the resistance in Section 2.3.2.1(2) of ENV 1994–1–1 may be carried out by using condition: Ma.Sd Ma.el where: Ma.Sd Mc.Sd Ma.el Mc.el

%

Mc.Sd Mc.el

# 1

is the design moment for the steel member due to actions effective prior to the hardening of the concrete is the design moment for the composite member due to actions effective after the hardening of the concrete is the moment that causes a stress at the flange of the steel member, defined in Section 4.4.1.4(3) of ENV 1994–1–1 is the minimum moment that causes a stress at the steel or concrete flange of the composite member, defined in Section 4.4.1.4(3) of ENV 1994–1–1.

4.4.2.2 Design methods D

(1) For beams with reinforced concrete encasement, the design resistance to vertical shear may be calculated by adding the design plastic shear resistance of the structural steel section according to Clause 4.4.2 125


of EC4: Part 1–1 and the design shear resistance of the concrete encasement according to Clauses 4.3.2.3 and 4.3.2.4.3 of EC2: Part 1–1. The design resistance of the encasement may be calculated including shear reinforcement provided that the stirrups are closed or attached to the web by appropriate welds. 4.4.3

Bending and vertical shear

D

(2) The design bending resistance Mf.Rd of cross sections in Class 3 and 4 should be determined by elastic theory. If the contribution of concrete encasement in bending and vertical shear may be taken into account then the interaction criterion for the design shear resistance Vpl.Rd according to Clause 4.4.2.2 may be used. The design plastic bending resistance Mf.Rd of the cross section consisting of the flanges only may be calculated with the plastic stress distributions given in Figure R1 of the NAD. (2) The design resistance Mf.Rd should be calculated following the same method (plastic or elastic) as that used for the determination of MRd. As a result, the definition of Mf.Rd is invalidated and replaced by: Mf.Rd is the design bending resistance of a cross section consisting of the flanges only, with effective sections as used in the calculation of Mrd.


F

4.4.4


D

(6) Concerning the references to Clause 5.6.2 of EC3: Part 1–1, reference is made to the NAD to EC3: Part 1–1. The shear resistance of the composite beam is calculated considering the buckling of the web as:

SF

Vba.Rd = Jbatwd / (M1 (7)(b) Replace the definition of Jcr with: Jcr is calculated according to Section 5.63 in SFS–ENV 1993–1–1:1992. It is the elastic critical buckling stress: Jcr ' 0,9 E a kJ (

tw d

)2

kJ = 4 + 5.34 / (a / d)2 kJ = 5.34 + 4 / (a / d)2

For beams having transverse stiffeners spaced a, and a / d < 1 For beams having transverse stiffeners spaced a, and a / d $ 1.

4.4.5

Interaction between bending and shear buckling

F

(c) The symbol Mpl.Rd in Clauses 5.6.7.2(3) and 5.6.7.3(5) of EC3 should be replaced by M rd, which is the design bending resistance of the composite section given by 4.4.1. Furthermore, in these Clauses, M f.Rd should be calculated elastically, irrespective of the class of cross section concerned (Mf.Rd = Mf.el.Rd). The moment-shear interaction on the resistance is evaluated as follows. Let Mf.Rd be the bending resistance of the cross section composed of the concrete section and steel flanges. There is no interaction, when: MSd # Mf.Rd and VSd # Vba.Rd.

SF

126


When VSd # 0,5Vba.Rd, the resistance MRd according to Section 4.4.1 may be assumed. When VSd > 0,5Vba.Rd and MSd > Mf.Rd, the next condition shall be satisfied: MSd # Mf.Rd + (MRd > Mf.Rd) [1 – (2VSd / Vba.Rd – 1)2]. 4.5

Internal forces and moments in continuous beams

4.5.1

General

D

(2) and (3) If the contribution of concrete encasement in bending and shear is taken into account for the resistance of the cross section, ‘cracked’ elastic global analysis according to EC4 Part 1–1, Clause 4.5.3 shall be used. The flexural stiffness EI2 shall be calculated according to Clause 5.2.2 of the NAD. For continuous beams a redistribution of bending moments in a way that satisfies equilibrium is allowed by a maximum amount of 15%.

4.5.3.4 Redistribution of moments in beams for buildings


F

(2)(a) Concerning the percentage of redistribution, p, given in Table 4.3, the reduction of a peak negative elastic moment, Mpic, is only applicable if the following conditions have been satisfied: M Rd # Mpic #

Mpic 1 &

p 100

8¯LT # 0,4 (see 4.6.3). (2)(a) For beams with partial shear connection, the sections of which must be of Class 1 or 2 (see 6.2.1), the application of the redistribution percentages indicated in Table 4.3 is permitted. 4.6.1

General

F

(1) Where isolated beams are used, the attached flange can be considered as being stable if in addition the distance between lateral supports is less than 30 times the slab width.

4.6.2

Check without direct calculation

F

(3)(k) In place of and instead of Euro-standards 19–57 and 53–62, reference should be made to AFNOR standards NF A 45–205 and NF A 45–201 respectively. (3)(k) In the absence of Euronorm 19–57 and Euronorm 53–62, the following documents should be used: BS 4, BS 4848: Part 4 or Euronorms 19–57 or 53–62. (3)(k) Euronorm 19–57 must be read as NEN EU 19 in conjunction with Euronorm 19–57. Euronorm 53–62 must be read as NEN EU 53 in conjunction with Euronorm 53–62.

IRL NL

127



Discuss me ...

4.6.3

Buckling resistance moment

NL UK

(1) The ‘boxed value’ 1,10 must be replaced by the value 1,0. (4) When calculating the elastic critical moment, Mcr, from Annex F of EC3: Part 1.1, the additional recommendations given in 6.1.3e of the NAD to DD ENV 1993–1–1: 1992 (EC3: Part 1.1) apply.

4.7

Web crippling

D

Reference is made to Clause 5.7 of the NAD to EC3: Part 1–1.

4.7.1

General

UK

Diagonal, tension and torsional stiffeners should be designed using the method given in 6.1.3(g) of the NAD to DD ENV 1993–1–1: 1992 (EC3: Part 1.1).

4.8

Composite columns

CZ

The calculation procedures for the design of most frequent types of composite columns are introduced. The practical formulas are in Annexes C and D.

4.8.2.2 Design procedures NL

The partial safety factors for prefabricated concrete elements, as meant in (12), must be determined in accordance with 6.1 and 6.2 of NEN 6720.

4.8.2.3 Imperfections NL

The buckling curves a, c and d as meant in (2) must be taken from Table 5.5.2 of Eurocode 3: Part 1.1.

4.8.2.5 Cover and reinforcement D NL UK

(2) With regard to the concrete cover, reference is made to Clause 4.1.3.3 of the NAD to EC2: Part 1–1. Delete reference to Eurocode 4: Part 1.2. (2) When determining the cover to reinforcement, the additional recommendations given in 6.4(a) and (b) of the NAD to DD ENV 1992–1–1: 1992 (EC2: Part 1) apply.

4.8.2.6 Shear between the steel and concrete components D

F

(1) In case of load introduction with connectors without sufficient ductility, and/or load introduction only over the concrete component of the composite section for the calculation of the shear forces, elastic analysis should be used taking into account effects of creep and shrinkage. (3) Figures are given in the NAD that illustrate several connection types and define the introduction length, p, which should be taken into account where applicable. 128



SF

(1) and (2) It is intended in the Clauses that where reactions are to be transferred from beams to column, it shall be verified that a transfer path exists where no large slips may occur that can invalidate the assumption of full interaction. (3) Limiting stresses, other than those given in Section 4.8.2.7, may be justified by testing. When designing tests for concrete-filled steel hollow sections, all information given in Chapter 10 is valid and, further, the next principles shall be followed: – minimum of 3 equal specimens shall be loaded for each series of tests – the results shall only be used for the verification of the columns for which the fabrication of the steel tubes is consistent with the tested ones – the results shall be exploited only for such members for which the ratio t / d is not less than that in the test series, t being the thickness of the wall and d the diameter or depth of the tube – when more general validity is required, t / d shall be varied in tests – the specimen may be a concrete-filled steel tube of the form similar to the column – an appropriate slip space shall be provided – the load and the slip at the far end of the specimen are recorded for the load-slip plot – the concrete part of the specimen is loaded with a uniform axial pressure – where practicable, the loading shall be continued to the stage where the concrete core slips without any force incrementation – the failure load of the test is determined from the load-slip plot of the test as being the value for which the concrete core has moved a distance of 3.5 lb / 1000, lb being the bond length of the specimen, – the characteristic strength Ju.Rk shall be 90% of the minimum value obtained in tests – the design value is Ju.Rd = Ju.Rk / (v with (v = 1,25.

4.8.2.7 Resistance to shear CH F

(2) Values valid only up to a depth of section of 200 mm. (2) For sections completely encased in concrete, or where connection is made onto the flange of the column, 0,4 N/mm2 should be taken instead of 0,6 N/mm2.

4.8.3

Simplified method of design

SF

The design method for doubly symmetrical columns shall be used as a whole, and not adopting any other principles or parts of other methods within it.

4.8.3.1 Scope UK

(3)(c) The term ‘relative slenderness’ in the heading of 4.8.3.7 has the same meaning as ‘non-dimensional slenderness’.

4.8.3.2 Partial safety factors (Ma, (a and (Rd NL

(1) The ‘boxed value’ 1,10 must be replaced by the value 1,0.

129


4.8.3.3 Resistance of cross sections to axial loads NL

The partial safety factors for prefabricated concrete elements, as meant in (1), must be determined in accordance with 6.1 and 6.2 of NEN 6720.

4.8.3.5 Effective elastic flexural stiffness of cross sections to axial loads F

(4) The occurrence of sway frames and/or unbraced frames is impossible following application of Clause 4.8.1(2).

4.8.3.6 Buckling lengths of a column


UK

Where no guidance on the buckling length is given in DD ENV 1993–1–1 (EC3: Part 1.1), the normal effective length for a strut given in 4.7.2 of BS 5950–1:1990 should be used. When calculating the elastic critical load, Ncr, a buckling length, l, of less than 0,7 times the system length, L, may be used for a member only where it can be demonstrated that the stiffness of the connecting members and of the connections to be used would justify such a value. In all other cases the buckling length, l, should not be taken as less than 0,7 times the system length.

4.8.3.9 Combined compression and bending UK

For members subject to combined compression and bending, the ratio Pn should be determined as follows: (1) Encased steel sections (including web filled sections) and rectangular filled sections: Provided that the non-dimensional slenderness, 8, does not exceed 1.0, the ratio Pn may be determined from the recommendations given in 4.8.3.13(4) of EC4: Part 1.1. For values of 8 in the range 1,0 to 2,0, Pn should be taken as zero. (2) Concrete-filled circular and square sections: For concrete-filled circular and square sections, the ratio Pn may be determined from the recommendations given in 4.8.3.13(4) of EC4: Part 1.1.

4.8.3.11 Resistance of cross sections in combined compression and uniaxial bending UK

The design moment resistance in combined compression and uniaxial bending should not exceed the design plastic moment, Mpl.Rd, irrespective of the normal force N.

4.8.3.12 Influence of shear forces D

(1) The share of the shear force Vsd in the components of the concrete and steel parts of the section may be determined with the ratio of the plastic bending strength of the individual sections by neglecting the effects of the shear force. For the resistance of a composite section in combined compression, uniaxial bending and shear, the influence of the shear force may be taken into account under consideration of Clause 4.4.2.2 by a reduced yield strength fyred for the shear area of the structural steel member, where: 130


fyred = fy [1 – (2VSd / Vpl.Rd – 1)2]. The design shear strength of the reinforced concrete part of the section should be calculated according to EC2: Part 1–1. 4.8.3.13 Resistances in combined compression and uniaxial bending D F

SF


UK

(6) Does not apply. Clause 4.8.3.13(7) of EC4: Part 1–1 should be used. (6) When NSd < ½Npm.Rd (Figure 4.12), the increase of bending resistance due to the normal force may be overestimated if the acting normal force N and the bending moment M are independent. This should be accounted for by reducing the partial safety factor for the favourable component Nsd by 20%. (8) Reference to Clause 4.8.3.11(3), which defines Mpl.Rd, is no longer valid and is replaced by a reference to Clause 4.8.3.2. For the interaction curve in Figure 4.14, the design shall be valid only for MRd / Mpl.Rd # 1. (5) When calculating the length : in Figure 4.14, it shall be verified that :d # 1 and :k # 1. (6) is not allowed for. The additional recommendations given in 6.2.3(g) of this NAD supplement the recommendations given in paragraph 6 and supersede those given in paragraph 7 of 4.8.3.13 of EC4: Part 1.1.

4.9.1

General [Internal forces and moments in frames]

D

(2) Further information about the terms sway, non sway, braced and unbraced is given in Annex A of the NAD. (7)(e) This check is invalidated by the references in Clauses 4.9.4.1(2) and 4.9.4.3(4) to EC3 [cf. Clause 5.2.5.3(7)].

F 4.9.2

Design assumptions

D

With regard to Table 4.8, reference is made to Tables B1 and D2 of the Annexes of the NAD to EC3: Part 1–1.

4.9.2.2 Simple framing UK

The additional recommendations given in Annex B of the NAD may be used for the design of columns in simple framing. As an alternative to the recommendations given in Annex B, cased columns may be designed using the method given in 6.3.2 of the NAD.

4.10.3.1 General D

Concerning the reference to Clause 5.6 of EC3, reference is made to the NAD to EC3: Part 1–1.

4.10.3.2 Distribution of forces between fasteners D

For the calculation of the forces of the fasteners, it should be assumed that the section remains plane.

131



4.10.5.4 Classification of rotational stiffness D

Reference is made to Clause 6.9.7.3 of the NAD to EC3: Part 1–1.

5

SERVICEABILITY LIMIT STATES

CZ

The rules for deflection calculations concerning composite beams with partial shear connection and concerning continuous beams with cracks in concrete slab are presented.

5.1

General

F

(1) For service conditions, one should limit vibrations caused by machines and oscillations due to harmonic resonance by having structures or parts of structures whose natural frequencies are sufficiently different from those from the oscillatory sources. In order to carry out an analysis of the natural frequencies and modes of a composite floor in a building, the use of characteristics for the uncracked composite sections is permitted with the secant modulus of elasticity, Ecm, given in 3.1.4.1 for short-term loading. For such an analysis, slip effects at the steel-concrete interface can be neglected. The fundamental natural frequency of a simply supported composite beam with a span greater than 10 m can be evaluated with the use of the following simplified formula: f '

NL

18 *

where f is given in Hz and * in mm. * is the instantaneous deflection of a composite beam produced by its self weight and the weight of the decking concerned (see 5.2.2). For floor decking upon which people normally walk (offices, residential buildings etc.), as well as for car parks, the fundamental natural frequency, f, should not be less than 3 Hz. For a gymnasium or floors of dance halls, the fundamental natural frequency, f, should not be less than 5 Hz. The influence of creep, as meant in (3), can also be taken into account by an effective modulus of elasticity for concrete, to be determined with the following equation: EN '

Eb 1 % Nj

As a supplement to (3), the influence of shrinkage can be taken into account by an effective modulus of elasticity for concrete, to be determined by the following equation: Er '

SF

Eb 1 % 0,5Nj

In both equations the value of Nj must be determined in accordance with Annex 4 of Eurocode 2: Part 1.1. (2) Yielding in the steel member and reinforcement in the serviceability limit state of a composite member is only allowed in clamped or continuous ends of the span, if the calculation model for the deflections 132


allows for yielding. At the section of the maximum hogging moment, the member shall be fully elastic. 5.2.1

General

CH

Limit values (nominal values for deformations): instead of this Section, Paragraph 3 33 of SIA 160 applies. Reference is made to Clause 4.2.1 of the NAD to EC3: Part 1–1. (5) In calculation and on drawings it should be indicated how much the deflection of the steel beams will be during the pouring of the concrete. It should be proven that the formwork can follow this deflection and that this deflection can be dealt with during construction. If this is only the case when concrete is poured in a specific order, it should be indicated on the drawing. (6) The deflection * just after pouring the concrete (= immediately appeared deflection by the self weight minus the cambering) shall not be more than 30 mm. Deviating from this rule is accepted if the nature or the purpose of the structure gives rise to this. (4) The recommended deflection limits for composite beams and slabs are based on Section 4.2.2 of SFS–ENV 1993–1–1 and are given in Table 5.1 of the NAD. Where the deflection affects the appearance, the soffit of the structure shall be used as a reference, and top surface for other cases.

D NL


SF

5.2.2

Calculation of maximum deflections of beams

D

For beams with concrete-encased sections according to Clause 4.1.2 the flexural stiffness EI2 shall be determined including the reinforcement and the area of concrete encasement in compression. For simplification the depth of concrete encasement in compression may be calculated from plastic theory, in accordance with Clause 4.4.1.2. For unpropped beams the pre-camber of the beam without concrete slab should be determined with the mean value of the flexural stiffness EI1 and EI2. (3) Deflections should be calculated for serviceability limit states, considering effective widths as defined by Clause 4.2.2.1 for global analysis for ultimate limit states. (5)(b) Forces resulting from an elastic behaviour and which act on shear connectors do not exceed 0,7 Prd. (6) In general, the simplified formulae underestimate deflections for simply supported beams with a span of less than 15 m. For this case, deflections should be calculated by use of the formulae given in the NAD. (7) For cantilevers where Fct exceeds 0,15fck, the stiffness should be reduced over 30% of the span of the cantilever. (7) Curve A only applies where uniformly distributed loads are present. For composite beams in buildings the calculation of deformations due to different temperatures between steel beam and concrete floor can be omitted. For composite beams in open air and for composite beams in buildings where the difference in temperature between steel beam and concrete floor is greater than 10°C, the deformations by the maximum expected difference in temperature should be calculated and added to the final deflection after concreting (= the static deflection due to self weight

F

NL

133


minus the cambering). For composite beams in open air the following differences in temperature should be considered: – a difference in temperature of 10°C, between the top of the concrete floor and the bottom of the steel beam, where the temperature varies linearly over the construction depth – a temperature bound of 5°C, at the interface between the concrete and the steel, where the temperature in the concrete floor and the steel beam is constant If a rough calculation is sufficient, an effective value or shrinkage of concrete ,’r = 60.10–5 can be assumed. 5.3

Cracking of concrete in beams

5.3.1

General

D

(12)(d) For limitation of crack width to about 0,3 or 0,5 mm, the limitation of the maximum spacing for reinforcement bars in accordance with 5.3.4 or alternatively the limitation of the maximum diameters according to Table 5.1 may be used. (7) Limits for crack width should be determined in accordance with Table 2 of NEN 6720.


NL 5.3.2

Minimum reinforcement

F

(2) The limit of 3 N/mm2 can be replaced by the value of fctm, which corresponds to the class strength at 28 days, if this value is less than 3 N/mm2.

5.3.4

Control of cracking due to direct loading, without calculation of crack widths

D

(3) The second-order effects of shrinkage (to be taken into account in hyperstatic structures) may be neglected only in beams that fulfil environment conditions of Class 1 as given in Table 4.1 of EC2: Part 1. (6) See Clause 5.3.1, paragraph 12(d), as modified by the NAD. (7) For beams with reinforced concrete encasement in accordance with Clause 4.1.2 of the NAD, the diameters of the longitudinal reinforcement of the encasement should be limited according to Table 5.1 of EC4: Part 1–1. (2) The increase in reinforcement stresses in continuous supports of a composite flexural member is due to the evaluation method, where only the tensile reinforcement is considered for the concrete section when calculating stiffnesses. The hogging stiffness of the structure is thus smaller than in reality, and the moment and the stress Fse are smaller than in a real structure.

SF

6

SHEAR CONNECTION IN BEAMS FOR BUILDINGS

CH

Remark: In the case of new structures in Switzerland the use of stud shear connectors and dowels (stud bolts) is usual. Contrary to the common practice in the Czech Republic the usage of steel sheeting without embossments and with the end anchorage only is forbidden.

CZ

134


6.1.2

Deformation capacity of shear connectors

6.1.3

Spacing of shear connectors

F

(4) To carry out additional checks, the partial shear connection method may be used in the way presented in 6.2.1.2 and 6.2.1.3. This method can also be used for other intermediate critical sections resulting from heavy concentrated loads or changes of sections.


6.2.1.3 Partial-shear connection with non-ductile connectors F

(2) This method is only applicable to shear connectors that possess a deformation capacity of at least 2 mm. Block connectors in solid slabs (see 6.3.4) cannot satisfy this requirement.

6.2.2

Beams in which elastic theory is used for resistance of one or more cross sections

NL

The influence of shrinkage, creep and eventually differences in temperature must be considered in accordance with 3.1.4.2 and the supplementary rules on 5.2.2 of this NAD. If no detailed calculations are made the resulting concentrated shear forces can be distributed triangle over a distance equal to the effective width of the concrete slab (see Figure in the NAD).

6.3.2.1 Headed studs - shear resistance UK

The design shear resistance, PRd, of shear connectors in lightweight concrete with a dry density exceeding 1750 kg/m3 should be taken as 90% of the value of the design shear resistance calculated for normal weight concrete with the same characteristic strength.

6.3.3.2 Sheeting with ribs transverse to the supporting beam D

(1) When using sheeting with holes and for studs welded through sheetings with a thickness t # 1,0 mm, the reduction factor kt according to equation 6.16 in EC4 should not exceed the values given in Table R2 of the NAD.

6.3.6

Block connectors with anchors or hoops in solid slabs

F

(3) For the design of the welds that fix the block connector to the steel beams, the eccentricity of the force should be taken into account.

6.4.1

General recommendations

NL

Supplement after 6.4.1.5: The studs must be produced of a steel grade with good weldability. By means of weld procedure as used in practice gives sufficient reliable weld.

135


6.4.1.2 Cover and compaction of concrete UK

When calculating the cover required for shear connectors, the specified cover for reinforcement should be in accordance with Table 6 of the NAD to 1992–1–1: 1992 (EC2: Part 1).

6.4.2

Stud connectors

F

(3) A clear spacing in the direction of longitudinal shear force less than 5d, but not less than 2,5d, may be adopted provided that the effect of grouping on the efficiency of the connection is taken into account.

6.4.5

Anchors and hoops

D

Manufacturing and testing of the welded connections should be in accordance with Clause 18.6.6 of DIN 1045/07.88 and DIN 4099. Supplement after (3): Anchor strips can be connected obtuse to the steel beam or with a branched off end joint and must be fully through welded. In the application with flank welds the kink in the bar must be produced by heated bending.


NL

6.5.2


6.5.2.1 Design friction resistance UK

(1) The design pre-loading force, Fp.Cd, used in design calculations should be determined in accordance with the recommendations given in 6.1.4d of the NAD to 1993–1–1: 1992. (2) If, after final tightening, the bolt or nut of a high strength friction grip bolt assembly installed in accordance with the recommendations given in BS 4604 is slackened off for any reason, the bolt, nut and washer (washers) should be discarded and not re-used.

6.5.3


F

(2) For consistency with EC3 – DAN and in view of the additional uncertainty due to the concrete, the value of the partial safety factor (v = 1,0 for serviceability limit states is no longer valid and the value (v = 1,25 should be adopted.

6.5.4

Detailing of friction grip bolts

NL

Supplement after (3): Procedure tests must be carried out to show that with the used method of tightening the required prestressed force is installed sufficiently reliably. The detailing of the structure must be such that at the location of the bolt connection the concrete slab is flat to the steel section. The interface must be free of paint, oil, dirt, loose rust, scale or other defect that could influence the friction coefficient negatively. If the flange of the steel section is treated with a coating, the friction coefficient, which can be taken into account, must be determined by specific tests. The influence of long-term loading must be considered. 136


6.6.2

Design resistance to longitudinal shear

D

(2) The resistance to longitudinal shear in accordance with equation 6.26; the contribution of the steel sheeting should be neglected. The basic shear strength JRd should be taken as: JRd = 0,09 3%fck (N/mm2 ). (2) Formula 6.26 is no longer valid and is replaced by:

F

vRd =

0,2 Acv 0 f ck (c


(2) In accordance with Clause 4.3.2.5 of EC2, the value of JRd shall be taken as zero in regions where the beam is subjected to a hogging moment (in longitudinal bending). 7

COMPOSITE SLABS WITH PROFILED STEEL SHEETING FOR BUILDINGS

D

The design according to Clause 7 requires the agreement of the superior building control authorities or a national technical approval related to the application for EC4: Part 1–1.

7.1

General

7.1.1

Scope

NL

(3) Delete the reference to Eurocode 3: Part 1.3.

7.2.1

Slab thickness and reinforcement

F

(3) Transverse and longitudinal reinforcement must be provided within the depth hc of the concrete. The minimum amount of reinforcement that should be used is 0,6 cm2/ml in each direction. This reinforcement must only be placed on the profiled steel sheet if the design of the shape of the ribs limits contact between the reinforcement and the steel sheet to some points. The maximum spacing of the bars should be determined in accordance with Clause 5.4.3.2.1 of EC2, by taking the value of h as being the overall depth of the composite slab, unless closer spacing is required for the control of cracking (Section 5.3).

7.2.3

Bearing requirements

F

(1) This Clause is invalidated and transferred to 7.5 because it refers to checks and does not concern construction details. Temporary or permanent supports to the steel sheet constitute lines of support, excluding all limited support. These can either correspond to the permanent supporting structure of the decking (shell or transverse beam), or to temporary structures (beams, battens etc.) that link up the heads of removable props. (6) Where additional propping is not provided, the cantilever of the steel sheeting should be limited beyond the outside edge of the line of support of the edge of decking to a value that does not exceed four times the depth of the profiled steel sheet, without exceeding 200 mm.

137


NL SF

(7) Breaks in the steel sheeting are only possible where there are permanent supports. (8) Where steel sheets overlap at their ends, the length of the lower steel that rests on the support and that is not covered by the upper sheet should be made greater than 25 mm. (9) Lines of support must be provided and adjusted according to execution plans. In the absence of any indication in execution documents, cambers are neglected. Props that are not self-stabilising should be cross-braced. (1) Delete the reference to Eurocode 3: Part 1.3. In composite slabs with profiled steel sheeting, the effect of web crippling due to the width of the bearing surface is considered according to RakMK Part B6, Section 4.7.

7.3.2.1 Profiled steel sheet as shuttering


F

NL

(1) Note: Until sufficient information is given in Eurocode 1, the following rules apply. (2) By way of simplification, it is quite acceptable to only retain the loading cases shown in this NAD. (3) These minimum values are not necessarily sufficient for excessive impact or heaping of concrete, or pipeline or pumping loads. If appropriate, provision should be made in design for the additional loading. Without the concrete, the sheet should be shown by test or calculation to be able to resist a characteristic line load, perpendicular to the ribs, of 2 kN/m, applied on a 0,2 m wide strip. (1) Add the reference NEN 6702 in relation to Eurocode 1. (4) Supplement: If the imposed load due to the ponding is more than 10% of the nominal load, the influence on the load bearing capacity of the profiled steel sheet during construction phase must be taken into account. With respect to this rule the following can be used: The ponding effect can be taken into account with the following application rules. If the moment of inertia of the profiled steel sheet is less than: 1,7

q eg q eg % 1,5

l 4 10&8

(q in kN/m2)

The additional load due to the deflection (ponding effect) must be taken into account. The value 1,5 represents the construction load in this formula, if R # 3 m. Where R > 3 m, the value of 1,5 can be modified into a reduced mean value of the construction load. When taken into account the additional load it can be assumed that the weight of the extra concrete is equal to the weight of an extra concrete depth of 2 / 3 * (see Figure in NAD), where: ä = deflection, including the ponding effect, at midspan, calculated according to 7.6.2.2 and due to the self weight of the profiled steel sheet and the concrete with a combination factor of 1,0 = 1,00 R for a slab that is simply supported on both sides = 0,85 R for a slab that is simply supported on one side and has fixed end supports or is continuously over the support on the other side

138


=

0,75 R for a slab that has fixed end supports or is continuously over the support on both sides = 2,00 R for a slab that is cantilevered. If ponding must be taken into account the increase of the deflection must be taken into account with the following factor n = n & 1


UK

1 1 & 0,117.10&8

l4 Ieff

If the ponding effect must be taken into account, a lower construction load with respect to the ultimate limit state design may be assumed, equal to 1,25 kN/m2 (for comparison 1,50 kN/m2 as given in 7.3.2.1). The recommendations on construction loads given in 2.2.3 of BS 5950–4:1993 supersede paragraphs 2 and 3 of 7.3.2.1 in EC4: Part 1.1. (4) When the central deflection, *, of the profiled steel sheeting during construction exceeds either 1/250 or 20 mm, the additional weight of concrete due to the deflection of the sheeting should be taken into account in the self-weight of the concrete slab and in the design of the supporting structure.

7.3.3

Load combinations and load cases

F

(1)

7.4.1

Profiled steel sheet as shuttering

F

(1) Where laying occurs on: – two permanent supports (with or without intermediate props) – more than two permanent supports with the use of props elastic analysis shall be used. Where sheeting is considered as continuous, flexural stiffness may be determined without consideration of the variation of stiffness due to parts of the cross section in compression not being fully effective. For cases where laying takes place on more than two permanent supports, without propping, a rigid-plastic analysis may be employed, based on a partial moment of resistance over intermediate supports. This partial moment of resistance must be determined experimentally or otherwise taken as zero. Furthermore, if rigid plastic is used, variations in strength due to plastic behaviour at the supports are to be taken into account during evaluation of deflections. For global analysis, linear elastic as well as non-linear elastic theory can be applied. (2) The reference to Eurocode 3: Part 1.3 should be deleted. As an alternative to elastic analysis, profiled steel sheeting may be analysed in accordance with the recommendations given in EC3: Part 1.3. (2) Profiled steel sheeting spanning onto a steel beam may be assumed to provide restraint to the beam flanges to which it is connected and should be fixed using: – shot fired fixings – self-tapping screws

NL UK

The whole of Clause 2.2.5 should be applied.

139


–

welding (including stud shear connectors welded through the sheeting) or – bolting. The spacing of fasteners should not be greater than 500 mm at the ends of sheets, nor greater than 1000 mm where the sheet is continuous. The design of the fixings should be in accordance with BS 5950–6. The stiffness of other types of shuttering or formwork is generally not sufficient to provide the necessary lateral restraint, unless specifically designed to do so. 7.4.2.1 Analysis D

(1) Plastic analysis shall be in accordance with EC2: Part 1–1, Clause 2.5.3.5.5.


7.4.2.2 Effective width for concentrated point and line loads F

(4) In order to ensure distribution of loads, transverse reinforcement must always be placed on or above the sheeting. This reinforcement must be calculated according to Eurocode 2 for transverse bending moments. (6) Due to application of (4), paragraph 6 is invalidated.

7.5.1


NL

Delete the reference to Eurocode 3: Part 1.3.

7.5.2


F

(2) The deflection of the sheeting under its self-weight plus the weight of the fresh concrete, but neglecting construction loads, should be limited to the maximum value: L / 180, where L is the effective span between supports (props being considered as being supports in this context). Also see Clause 7.3.2.1(4). (1) Delete the reference to Eurocode 3: Part 1.3.

NL

7.6.1.2 Flexure D F

(4) and (5) If not shown by a more accurate calculation in Equations 7a and 7b as well in Figures 7.7 and 7.8 of EC4: Part 1, the design concrete strength should be reduced from 0,85 fck / (c to . 0,7 fck / (c. (1) Where redistribution of moments has been permitted by plastification over intermediate supports in the construction phase, the contribution of the steel sheeting shall be neglected in checks for bending resistance under hogging moments.

7.6.1.3 Longitudinal shear for slabs without end anchorage D

(1) The design values of the factors m and k and the design shear strength Ju.Rd for a calculation according to Annex E should be taken from national technical approvals related to the application of EC4. See Clause 3.4.1. (2) The partial safety factor (vs should be in accordance with the additional regulations given in Clause 10.3.1.5 of the NAD. 140


F

(4) Where the composite slab is continuous for end spans, the equivalent simple span between the end support and the point of contraflexure should be used. (4) Where the composite slab is designed as continuous, it is permitted to use an equivalent isostatic bay when determining shear resistance. Figure 7.10 is invalidated and replaced by the Figure given in the NAD.

7.6.1.4 Longitudinal shear for slabs with end anchorage F

Paragraph 2 is a rule not a principle. (3) The formula for kN is invalidated when the limitation of ‘a’ below is applied and is replaced by: kN = 1 % a # 3,0 dd0

7.6.1.5 Vertical shear D

The basic shear strength should be in accordance with Clause 6.6.2 of the NAD.


7.6.1.6 Punching shear D

In Equation 7.9 of EC4: Part 1–1 the basic shear strength JRd given in Clause 6.6.2 of this NAD, increased by 20%, should be used.

7.6.2.2 Deflections F

SF

(7) It is considered that there is no initial slip if the slip occurring concurrently at any end is less than 0,5 mm. (10) Where end slip exceeding 0,5 mm occurs at a load below 1,2 times the design service load, end anchors should be provided. Alternatively, deflections should be calculated including the effect of end slip (which should be carried by consulting approved test information). (4) The recommended deflection limits for composite beams and slabs are based on Section 4.2.2 of SFS–ENV 1993–1–1 and are given in Table 5.1 of the NAD. Where the deflection affects the appearance, the soffit of the structure shall be used as a reference, and the top surface for other cases.

8

FLOORS WITH PRECAST CONCRETE SLABS FOR BUILDINGS

8.1

General

D

ENV 1992 1–3 Eurocode 2: Part 1–1 is not available at present. Reference is made to DIN 1045/07.88, Clause 19. (2) Reference should also be made to Journals of Technical Directions common to the procedures for floors “CPT: Floors”. – Part 1. Floors ribbed with prefabricated joists combined with in-situ cast concrete or combined with other prefabricated components by in-situ cast concrete. – Part 2. Solid slabs made up of prefabricated slabs acting as floor shuttering and in-situ cast concrete.

F

141



NL SF

– Part 3. Floors made up of pre-stressed concrete hollow slabs. (2) Replace the reference to Eurocode 2: Part 1.3 by NEN 6720. (2) Where hollow-core slabs are employed as flooring units and supported on beams, allowance shall be made for the possible reduction of the vertical shear resistance of the slabs. The resistance may reduce due to composite interaction of the slabs with the beam and can be critical with respect to the capacity of the slabs.

8.2

Actions

NL

(2) Replace the reference in the ENV Note to Eurocode 1 by NEN 6702.

8.3

Partial safety factors for materials

NL

Replace the reference to Eurocode 2 for the partial safety factors of prefabricated concrete by NEN 6720.

8.4.1

Support arrangements

NL

(2)

8.4.2

Joints between precast members

SF

(2) The joint between hollow-core units may be considered as transferring shears along the joint, if the detraction of the interface sides is prevented, e.g. by employing a hoop reinforcement around the flooring panel. When the slab ends are tied to the beam with the aid of shear connectors, a behaviour similar to the hoop reinforcement may be assumed.

8.4.3

Interfaces

NL

(2)

9

EXECUTION

CH

This is only valid in an informative sense. It describes the minimum requirements for fabrication and erection only in so far as the assumptions for design and dimensioning according to Eurocode 4 are fulfilled. If the conditions for fabrication and erection laid down in SIA 161 and 161/1 as well as SIA 162 and 162/1 are complied with, the requirements for the use of Eurocode 4 are also fulfilled.

9.1

General

F

(2) This Chapter gives specific recommendations for the execution of composite structures with the view of ensuring conformity with design rules. In addition, the relevant parts of Chapters of EC2 and EC3 are applicable to composite structures.

Replace the reference to Eurocode 2: Part 1.3 by NEN 6720.

Replace the reference to Eurocode 2: Part 1.3 by NEN 6720.

142



Discuss me ...

9.2

Sequence of construction

F

(1) The sequence of construction shall be compatible with the design (for example, because of its influences on stresses, connections and deflections). All information necessary to ensure this compatibility shall be clearly specified in the execution document and other instructions concerning erection.

9.4

Accuracy during construction and quality

F

Title changed to “Erection conditions during construction – Quality Control”.

9.4.1

Static deflection during and after concreting

NL

Supplement to (3): In design, account must be taken of the concrete gang during construction (order and speed) and the use of temporary props. The chosen concrete gang, the construction load assumptions and the method of construction must be indicated in the calculation and on the drawing. If during the construction phase the profiled steel sheet acts as a diaphragm or a lateral restraint for the beams, this should also be indicated in the calculation and on the drawing. It must be secured that during construction no damage is made to partly hardened concrete as a result of little composite action between steel and concrete when the concrete gangs are in operation.

9.4.3.1 Headed studs in structures for buildings D F NL

Manufacturing and testing the welded stud connections should be in accordance with DIN 8563, Part 10. (4) Reference should be made to the standards NF A 89–020–2 and NF E 25–140 concerning fastening of studs. Supplement to (1): For every new work and every time that welding equipment is brought to the site, a minimum of two test welds must be made and mechanically tested.

9.4.3.2 Anchors, hoops, block connectors D

Welded connections with reinforcing steel should be in accordance with Clause 18.6.6 of DIN 1045/07.88.

9.4.3.3 Friction grip bolts F

(1) The interface may be painted, or have an applied finish, on condition that the friction coefficient µ is determined by appropriate tests that conform to Clause 6.5.2.1(3).

9.4.3.4 Corrosion protection in the interface F

(1) The second paragraph of the Clause may be extended to protection by galvanizing or metal spraying. It does not apply where friction grip bolts are used, Reference 9.4.3.3(1). 143


9.4.4

Composite slabs with profiled steel sheeting

D

The execution according to Clause 9.4.4 requires the agreement by the building control authorities on buildings or a national technical approval related to the application of EC4: Part 1–1.

9.4.4.1 Profiled steel sheet as shuttering – fixing of sheets NL

(2)

Delete the reference to Eurocode 3: Part 1.3.

9.4.4.3 Loads


F

The values of the construction and storage loads assumed in design of the sheeting shall be clearly shown on the relevant site plans. It should be ensured that the spread of the concrete on the shuttering is carried out without exceeding the value envisaged for the pouring loads, which correspond to a brief average over-thickness of 3 cm of concrete. Profuse dumping of the concrete onto the shuttering should be avoided, in particular in areas far from supports present at the time of pouring. Visible marks that are sufficiently numerous will make the upper layer of the slab be apparent for assessment of the useful quantity of concrete.

9.4.4.4 Stud connectors welded through profiled sheeting D

For welding studs the general qualification-certification according to DIN 18 800 Part 7 is required. If the national technical approvals give more restrictive or extensive regulations, these should be used.

9.4.4.5 End anchorages F

Deformation of the sheeting after laying is not permitted.

9.4.4.6 Temporary supports F

Lines of support shall be erected and lined up according to erection drawings. In the absence of indications on the erection drawings, temporary props should be set at the level of permanent supports. Nonself stabilising props shall be embraced.

10

DESIGN ASSISTED BY TESTING

CZ D

Previous Czech codes have not contained a similar Chapter. Design assisted by testing according to Chapter 10 requires for every case the agreement by the superior building control authorities or a national technical approval.

10.1

General

F

(1)

For tests on profiled metal sheeting, refer to Part 1.3 of EC3.

144


10.2.4

Testing procedure

F

(2) Furthermore, these load increments should be spread out at regular intervals over this minimum period of 15 minutes.

10.2.5

Test evaluation

NL

(2) Replace the reference to Annex Z of Eurocode 3 by 7.1.5.2.2 of NEN 6770.

10.3.1.2 Testing arrangement D

(6) For the determination of the factors m and k at least, tests for two groups with three test specimens for each group should be performed. (7) When the tests are used to determine Juk, not less than 5 tests having a value 0,7 # 0 < 1,0 should be taken for the determination of the design values. An additional test should be carried out with a shear span length Ls = 3 Lt to check ductility.

10.3.1.3 Preparations of specimens


F

(2) Measured spacings and depths of embossments on the specimens shall be within tolerances defined in standards or reference documents.

10.3.1.4 Test loading procedure D

(2) For the groups A and B according to Figure 10.7 of EC4: Part 1–1 three tests should be carried out. An additional test in each group is required for the determination of the level of cycling loading. The failure load Wt is the load that causes a significant decrease of loading in the load-deflection diagram in deflection-controlled tests or in constant loading level in force-controlled tests. If subsequently an increase of 10% of loading is possible (ductile behaviour), the maximum load should be taken as the failure load.

10.3.1.5 Determination of design values for m and k D F

(5) If the deviation of any individual test exceeds 10% from the mean value in one or both groups, the test evaluation and the partial safety factor should be determined in accordance with Annex Z of EC3. (1) The shaded segment of Clause 10.3.1.5(1) is withdrawn.

10.3.2

Specific tests

10.3.2.5 Determination of the design resistance D

(c) The design resistance is 0,65 times the average failure load. Concerning the definition of the failure load Wt, reference is made to Clause 10.3.1.4.

145


ANNEX A A1

Scope

F

Clauses A.2, A.3 and A.4 are withdrawn and replaced by the Clauses AP.5 (list of reference standards) in the Foreword.

A.2.1

Standards mentioned in Eurocode 2

IRL

In the absence of DP 9690 and ENV 206, IS326 “Code of practice for the structural use of concrete” should be used instead. Documents BS 4449, BS 4482 and BS 4483 should be used instead of EN 10 080. Delete the reference to ISO (DP) 9690 (in preparation). Replace ENV 206 (1989/02) by NEN 950. Replace EN 10 080 (in preparation) by 5.1.2 of NEN 6720.

NL

ANNEX B


REFERENCE DOCUMENTS

LATERAL-TORSIONAL BUCKLING

B.1.1

Simplified method

F

(2) For a Class 3 or 4 section, the expression for 8¯LT given in (1) is not applicable. For a Class 3 section, the critical moment can be calculated directly by the formula: kc

Mcr = 26

E a C4 1 &

La2

b f3/2

.

tw3/2

.

tf

1/2

hs

and 8¯LT can be calculated in accordance with 4.6.3(3). The coefficient KC is given in B.1.3 or B.1.4 according to the case. For Class 4 webs, stability against buckling may be established by checking lateral-buckling stability of the isolated compression flange together with one-third of the compressed part of the web. Mcr can also be determined from Annex F of EC3 for the steel-only elements [see Clause 4.6.3(4)]. B.1.2

Elastic critical moment

F

(6)

The expression for s/b is withdrawn, and replaced by:

s 0,4 2 # f . d 2 (1&PLT 8LT) b ks u which takes note of the fact that the favourable effect of the number of studs per row is not taken into account. (7) Where shear connectors other than studs are used, a design with shear strength Prd and satisfying Clause 6.1.1(5), the condition clarified in B.1.2(6)I for s/b can be used, provided that fud2 is replaced with 2 PRd.

146


ANNEX C

SIMPLIFIED CALCULATION METHOD FOR RESISTANCE OF DOUBLY SYMMETRIC COMPOSITE CROSS SECTIONS IN COMBINED COMPRESSION AND BENDING

C.1

Scope and assumptions

UK

The design moment of resistance in combined compression and uniaxial bending should not exceed the design plastic resistance, Mpl.Rd, irrespective of the normal force N.

C.4

Bending resistances

UK

The design moment of resistance in combined compression and uniaxial bending should not exceed the design plastic resistance, Mpl.Rd, irrespective of the normal force N.

C.6.2

Major-axis bending of encased I sections

F

(1)

The formula C.10 is withdrawn and replaced by:


Wpa = ANNEX D

(h & 2t f)2 . tw 4

% b t f (h & tf)

(C.10)

DESIGN OF COMPOSITE COLUMNS WITH MONOSYMMETRICAL CROSS SECTIONS – SIMPLIFIED METHOD

D.4

Design for compression and uniaxial bending

UK

The design moment of resistance in combined compression and uniaxial bending should not exceed in magnitude the appropriate design plastic resistance moment Mpl.y–Rd or Mpl.y+Rd, irrespective of the normal force N.

ANNEX E

PARTIAL SHEAR COMPOSITE SLABS

CONNECTION

METHOD FOR

E.2

Determination of Ju.Rd

D

(2) and Figure E1. Instead of 0,85fcm the value 0,8fcm should be used. See also Clause 7.6.1.2. (4) and (5) If the deviation of any individual test result from the mean value does not exceed 10%, the characteristic value of the horizontal shear strength may be taken as the minimum value reduced by 10%. The design shear strength Ju.Rd is the characteristic shear strength (v = 1,25. In case of a deviation by more than 10% the test evaluation and the determination of the partial safety-factor should be in accordance with Annex Z of EC3.

E.3

Verification of the longitudinal shear resistance

D

(2) Instead of 0,85 f ck / (C the concrete strength 0,70 f ck / (C according to Clause 7.6.1.2 should be used for the calculation of Ncf.

147



Discuss me ...

E.4

Verification of composite slabs with end anchorage

D

(2) See Clause E.2, paragraph 2. (3) and (4) The characteristic resistance and the design value should be determined in accordance with E.2, paragraphs 4 and 5. (5) See Clause E.3, paragraph 2.

E.5

Verification of composite slabs with additional reinforcement

D

(1)

See Clause E.3, paragraph 2.

148

Technical Report: Comparison of National Application Documents for Eurocode 3: Part 1.1 and Eurocode 4: Part 1.1

Examples to Eurocode 3

Starlight [Part 3 Of 4]

Eurocode 3. Design of steel structures

Confessor: Chainfire Trilogy, Part 3 (Sword Of Truth, Book 11)

Confessor: Chainfire Trilogy, Part 3 (Sword Of Truth, Book 11)

Star Light Part 3 of 4)

Worked Example to Eurocode 2 Vol. 1

Eurocode 6 - Design Of Masonry Structures

Messerschmitt Me109 - (Part 4)

Supermarine Spitfire (Part 4)

Culinary Herbs, Part 4

Starlight [Part 2 Of 4]

Destiny's Call Part 4

The Beginning, Part 4

Hawker Hurricane (Part 4)

Ethics Part 4

The 9 11 Commission Report

Destiny's Call Part 4

Joy of Learning - Part 3

Handbook of Macroeconomics, Part 3

Destiny's Call Part 3

Supermarine Spitfire (Part.3)

Discovering sourdough - part 3

Star Light Part 4 of 4)

Culinary Herbs, Part 3

The Beginning, Part 3

US destroyers part 3

Spinoza, Ethics, Part 3

Luftwaffe. Part 3

Henry VI Part 3

Technical Report: Comparison of National Application Documents for Eurocode 3: Part 1.1 and Eurocode 4: Part 1.1

Examples to Eurocode 3

Starlight [Part 3 Of 4]

Eurocode 3. Design of steel structures

Confessor: Chainfire Trilogy, Part 3 (Sword Of Truth, Book 11)

Confessor: Chainfire Trilogy, Part 3 (Sword Of Truth, Book 11)

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