Designers’ Guide to En 1992-2. Eurocode 2: Design of Concrete Structures. Part 2: Concrete Bridges

383 Pages·2007·4.171 MB·English

by  Hendy, C. R., Smith, D. A.

DESIGNERS’ GUIDES TO THE EUROCODES
DESIGNERS’ GUIDE TO EN 1992-2
EUROCODE 2: DESIGN OF CONCRETE STRUCTURES
PART 2: CONCRETE BRIDGES
Eurocode Designers’ Guide Series
Designers’ Guide to EN 1990. Eurocode: Basis of Structural Design. H. Gulvanessian, J.-A. Calgaro and
M.Holicky´.0727730118.Published2002.
Designers’ Guide to EN 1994-1-1. Eurocode 4: Design of Composite Steel and Concrete Structures. Part 1.1:
GeneralRulesandRulesforBuildings.R.P.JohnsonandD.Anderson.0727731513.Published2004.
Designers’ Guide to EN 1997-1. Eurocode 7: Geotechnical Design – General Rules. R. Frank, C. Bauduin,
R.Driscoll,M.Kavvadas,N.KrebsOvesen,T.OrrandB.Schuppener.0727731548.Published2004.
Designers’GuidetoEN1993-1-1.Eurocode3:DesignofSteelStructures.GeneralRulesandRulesforBuildings.
L.GardnerandD.Nethercot.0727731637.Published2004.
Designers’GuidetoEN1992-1-1andEN1992-1-2.Eurocode2:DesignofConcreteStructures.GeneralRules
andRulesforBuildingsandStructuralFireDesign.A.W.BeebyandR.S.Narayanan.072773105X.Published
2005.
Designers’ Guide to EN 1998-1 and EN 1998-5. Eurocode 8: Design of Structures for Earthquake Resistance.
General Rules, Seismic Actions, Design Rules for Buildings, Foundations and Retaining Structures. M. Fardis,
E.Carvalho,A.Elnashai,E.Faccioli,P.PintoandA.Plumier.0727733486.Published2005.
Designers’Guide to EN1995-1-1. Eurocode 5:Design ofTimberStructures. Common Rulesandfor Rulesand
Buildings.C.Mettem.0727731629.Forthcoming:2007(provisional).
Designers’ Guide to EN 1991-4. Eurocode 1: Actions on Structures. Wind Actions. N. Cook. 0 7277 3152 1.
Forthcoming:2007(provisional).
Designers’GuidetoEN1996.Eurocode6:Part1.1:DesignofMasonryStructures.J.Morton.0727731556.
Forthcoming:2007(provisional).
Designers’ Guide to EN 1991-1-2, 1992-1-2, 1993-1-2 and EN 1994-1-2. Eurocode 1: Actions on Structures.
Eurocode 3: Design of Steel Structures. Eurocode 4: Design of Composite Steel and Concrete Structures. Fire
Engineering (Actions on Steel and Composite Structures). Y. Wang, C. Bailey, T. Lennon and D. Moore.
0727731572.Forthcoming:2007(provisional).
Designers’GuidetoEN1993-2.Eurocode3:DesignofSteelStructures.Bridges.C.R.HendyandC.J.Murphy.
0727731602.Forthcoming:2007(provisional).
Designers’GuidetoEN1991-2,1991-1-1,1991-1-3and1991-1-5to1-7.Eurocode1:ActionsonStructures.
Traffic Loads and Other Actions on Bridges. J.-A. Calgaro, M. Tschumi, H. Gulvanessian and N. Shetty.
0727731564.Forthcoming:2007(provisional).
Designers’GuidetoEN1991-1-1,EN1991-1-3and1991-1-5to1-7.Eurocode1:ActionsonStructures.General
Rules and Actions on Buildings (not Wind). H. Gulvanessian, J.-A. Calgaro, P. Formichi and G. Harding.
0727731580.Forthcoming:2007(provisional).
Designers’GuidetoEN1994-2.Eurocode4:DesignofCompositeSteelandConcreteStructures.Part2:General
RulesandRulesforBridges.C.R.HendyandR.P.Johnson.0727731610.Published2006.
www.eurocodes.co.uk
DESIGNERS’ GUIDES TO THE EUROCODES
DESIGNERS’ GUIDE TO EN 1992-2
EUROCODE 2: DESIGN OF
CONCRETE STRUCTURES
PART 2: CONCRETE BRIDGES
C. R. HENDY and D. A. SMITH
PublishedbyICEPublishing,OneGreatGeorgeStreet,Westminster,LondonSW1P3AA.
FulldetailsofICEPublishingsalesrepresentativesanddistributorscanbefoundat:
www.icevirtuallibrary.com/info/printbooksales
Firstpublished2007
Reprinted2010
Reprintedwithamendments2013
EurocodesExpert
Structural Eurocodes offer the opportunity of harmonized design standards for the European
construction market and the rest of the world. To achieve this, the construction industry needs to
become acquainted with the Eurocodes so that the maximum advantage can be taken of these
opportunities
EurocodesExpertisanewICEandThomasTelfordinitiativesetuptoassistincreatingagreater
awarenessoftheimpactandimplementationoftheEurocodeswithintheUKconstructionindustry
Eurocodes Expert provides a range of products and services to aid and support the transition to
Eurocodes. For comprehensive and useful information on the adoption of the Eurocodes and their
[e-mail]
AcataloguerecordforthisbookisavailablefromtheBritishLibrary
ISBN:978-0-7277-3159-3
#TheauthorsandThomasTelfordLimited2007
Allrights,includingtranslation,reserved.ExceptaspermittedbytheCopyright,DesignsandPatents
Act1988,nopartofthispublicationmaybereproduced,storedinaretrievalsystemortransmitted
in any form or by any means, electronic, mechanical, photocopying or otherwise, without the
prior written permission of the Publisher, ICE Publishing, One Great George Street, Westminster,
LondonSW1P3AA.
Thisbookispublishedontheunderstandingthattheauthorsaresolelyresponsibleforthestatements
made and opinions expressed in it and that its publication does not necessarily imply that such
statements and/or opinions are or reflect the views or opinions of the publishers. While every effort
has been made to ensure that the statements made and the opinions expressed in this publication
provideasafeandaccurateguide,noliabilityorresponsibilitycanbeacceptedinthisrespectbythe
authorsorpublishers.
TypesetbyAcademicþTechnical,Bristol
PrintedandboundbyCPIGroup(UK)Ltd,CroydonCR04YY
Preface
Aims and objectives of this guide
Theprincipalaimofthisbookistoprovidetheuserwithguidanceontheinterpretationand
useofEN1992-2andtopresentworkedexamples.Itcoverstopicsthatwillbeencountered
intypicalconcretebridgedesignsandexplainstherelationshipbetweenEN1992-2andthe
otherEurocodes.
EN1992-2isnota‘standalone’documentandrefersextensivelytootherEurocodes.Its
format is based on EN 1992-1-1 and generally follows the same clause numbering. It
identifies which parts of EN 1992-1-1 are relevant for bridge design and adds further
clauses that are specific to bridges. It is therefore not useful to produce guidance on
EN 1992-2 in isolation and so this guide covers material in EN 1992-1-1 which will need
to be used in bridge design.
This book also provides background information and references to enable users of
Eurocode2 to understand the origin and objectives of its provisions.
Layout of this guide
EN1992-2hasaforeword,13sectionsand17annexes.Thisguidehasanintroductionwhich
correspondstotheforewordofEN1992-2,Chapters1to10,whichcorrespondtoSections1
to10oftheEurocodeandAnnexesAtoQwhichagaincorrespondtoAnnexesAtoQofthe
Eurocode.
Theguidegenerallyfollowsthesectionnumbersandfirstsub-headingsinEN1992-2sothat
guidancecanbesoughtonthecodeonasectionbysectionbasis.Theguidealsofollowsthe
format of EN 1992-2 to lower levels of sub-heading in cases where this can conveniently be
done and where there is sufficient material to merit this. The need to use several Eurocode
parts can initially make it a daunting task to locate information in the order required for a
real design. In some places, therefore, additional sub-sections are included in this guide to
pull together relevant design rules for individual elements, such as pile caps. Additional
sub-sectionsareidentifiedassuchinthesub-sectionheading.
The following parts of the Eurocode are intended to be used in conjunction with
Eurocode2:
EN 1990: Basis of structural design
EN 1991: Actions on structures
EN 1997: Geotechnical design
EN 1998: Design of structures forearthquake resistance
hENs: Construction productsrelevantfor concretestructures
EN 13670: Execution (construction) ofconcrete structures
Thesedocumentswillgenerallyberequiredforatypicalconcretebridgedesign,butdiscus-
sion on them isgenerallybeyond the scope ofthis guide.
DESIGNERS’ GUIDE TO EN 1992-2
In this guide, references to Eurocode 2 are made by using the abbreviation ‘EC2’ for
EN 1992, so EN 1992-1-1 is referred to as EC2-1-1. Where clause numbers are referred to
in thetext,they are prefixed by thenumber ofthe relevantpart ofEC2. Hence:
. 2-2/clause 6.3.2(6) meansclause 6.3.2, paragraph (6), ofEC2-2
. 2-1-1/clause6.2.5(1) means clause 6.2.5,paragraph (1), of EC2-1-1
. 2-2/Expression (7.22)means equation (7.22) inEC2-2
. 2-1-1/Expression (7.8) means equation (7.8)in EC2-1-1.
Notethat,unlikeinotherguidesinthisseries,evenclausesinEN1992-2itselfareprefixed
with ‘2-2’. There are so many references to other parts of Eurocode 2 required that to do
otherwise would beconfusing.
Where additional equations are provided in the guide, they are numbered sequentially
within each sub-section of a main section so that, for example,the third additional expres-
sion within sub-section 6.1 would be referenced equation (D6.1-3). Additional figures and
tables follow the same system. For example, the second additional figure in section 6.4
would be referenced Figure6.4-2.
Acknowledgements
Chris Hendy would like to thank his wife, Wendy, and two boys, Peter Edwin Hendy and
Matthew Philip Hendy, for their patience and tolerance of his pleas to finish ‘just one
more section’.
DavidSmithwouldliketothankhiswife,Emma,forherlimitlesspatienceduringprepara-
tionofthisguide.Healsoacknowledgeshisson,WilliamThomasSmith,andthecontinued
supportof Brian and Rosalind Ruffell-Ward from the verybeginning.
Bothauthorswouldalsoliketothanktheiremployer,Atkins,forprovidingbothfacilities
andtimefortheproductionofthisguide.TheyalsowishtothankDrPaulJacksonandDr
Steve Denton fortheir helpful commentson theguide.
Chris Hendy
David A. Smith
vi
Contents
Preface v
Aims and objectives of this guide v
Layoutof this guide v
Acknowledgements vi
Introduction 1
Additional information specific toEN 1992-2 2
Chapter 1. General 3
1.1. Scope 3
1.1.1. Scopeof Eurocode 2 3
1.1.2. Scopeof Part 2 ofEurocode 2 4
1.2. Normative references 4
1.3. Assumptions 4
1.4. Distinction between principles andapplication rules 5
1.5. Definitions 5
1.6. Symbols 5
Chapter 2. Basis of design 7
2.1. Requirements 7
2.2. Principles oflimit statedesign 7
2.3. Basic variables 7
2.4. Verification by the partial factor method 9
2.4.1. General 9
2.4.2. Designvalues 9
2.4.3. Combinationsof actions 9
2.5. Design assisted bytesting 10
2.6. Supplementaryrequirementsfor foundations 10
Chapter 3. Materials 11
3.1. Concrete 11
3.1.1. General 11
3.1.2. Strength 11
3.1.3. Elasticdeformation 14
3.1.4. Creepand shrinkage 14
3.1.5. Concretestress–strain relation fornon-linear structural
analysis 19
DESIGNERS’ GUIDE TO EN 1992-2
3.1.6. Design compressive and tensile strengths 20
3.1.7. Stress–strain relationsfor thedesign of sections 21
3.1.8. Flexural tensilestrength 22
3.1.9. Confined concrete 23
3.2. Reinforcing steel 23
3.2.1. General 23
3.2.2. Properties 23
3.2.3. Strength 23
3.2.4. Ductility 24
3.2.5. Welding 25
3.2.6. Fatigue 25
3.2.7. Design assumptions 25
3.3. Prestressing steel 25
3.3.1. General 25
3.3.2. Properties 26
3.3.3. Strength 27
3.3.4. Ductilitycharacteristics 27
3.3.5. Fatigue 28
3.3.6. Design assumptions 28
3.4. Prestressing devices 29
3.4.1. Anchorages and couplers 29
3.4.2. External non-bondedtendons 29
Chapter 4. Durability and cover to reinforcement 31
4.1. General 31
4.2. Environmental conditions 32
4.3. Requirements fordurability 35
4.4. Methods of verification 36
4.4.1. Concretecover 36
Chapter 5. Structural analysis 39
5.1. General 39
5.2. Geometric imperfections 40
5.2.1. General(additional sub-section) 40
5.2.2. Arches(additional sub-section) 43
5.3 Idealization of thestructure 44
5.3.1 Structural models foroverallanalysis 44
5.3.2. Geometric data 44
5.4. Linear elastic analysis 48
5.5. Linear elastic analysis withlimited redistribution 49
5.6. Plasticanalysis 52
5.6.1. General 52
5.6.2. Plastic analysisforbeams, frames and slabs 52
5.6.3. Rotation capacity 53
5.6.4. Strut-and-tiemodels 56
5.7. Non-linear analysis 58
5.7.1. Method for ultimate limit states 58
5.7.2. Scalar combinations 60
5.7.3. Vector combinations 61
5.7.4. Method for serviceability limit states 62
5.8. Analysis ofsecond-order effects with axial load 62
5.8.1. Definitionsand introduction tosecond-order effects 62
5.8.2. General 63
5.8.3. Simplified criteria forsecond-order effects 64
viii
CONTENTS
5.8.4. Creep 69
5.8.5. Methodsof analysis 70
5.8.6. General method – second-order non-linear analysis 70
5.8.7. Second-order analysis based on nominal stiffness 71
5.8.8. Method basedon nominal curvature 76
5.8.9. Biaxialbending 80
5.9. Lateral instability ofslender beams 80
5.10. Prestressed members and structures 81
5.10.1. General 81
5.10.2. Prestressing force during tensioning 82
5.10.3. Prestressforce 83
5.10.4. Immediate lossesof prestress forpre-tensioning 84
5.10.5. Immediate lossesof prestress forpost-tensioning 85
5.10.6. Time-dependentlosses 90
5.10.7. Consideration of prestress inthe analysis 95
5.10.8. Effectsof prestressing atthe ultimatelimit state 96
5.10.9. Effectsof prestressing atthe serviceability and fatigue
limit states 98
5.11. Analysis forsomeparticular structural members 104
Chapter 6. Ultimate limit states 105
6.1. ULS bending withor without axial force 105
6.1.1. General (additional sub-section) 105
6.1.2. Reinforced concrete beams(additionalsub-section) 105
6.1.3. Prestressed concrete beams(additionalsub-section) 118
6.1.4. Reinforced concrete columns (additional sub-section) 121
6.1.5. Brittle failure ofmembers with prestress (additional
sub-section) 126
6.2. Shear 131
6.2.1. General verification procedurerules 132
6.2.2. Members not requiringdesign shear reinforcement 133
6.2.3. Members requiringdesign shear reinforcement 140
6.2.4. Shearbetween web and flangesof T-sections 154
6.2.5. Shearat theinterface between concretecast atdifferent
times 158
6.2.6. Shearand transverse bending 160
6.2.7. Shearin precast concrete and composite construction
(additional sub-section) 160
6.3. Torsion 166
6.3.1. General 166
6.3.2. Designprocedure 167
6.3.3. Warping torsion 171
6.3.4. Torsionin slabs (additional sub-section) 172
6.4. Punching 175
6.4.1. General 175
6.4.2. Load distribution and basic control perimeter 176
6.4.3. Punching shear calculation 177
6.4.4. Punching shear resistance of slabs and bases without
shear reinforcement 179
6.4.5. Punching shear resistance of slabs and bases withshear
reinforcement 183
6.4.6. Pile caps(additional sub-section) 185
6.5. Design withstrut-and-ties models 193
6.5.1. General 193
ix