DESIGNERS’ GUIDES TO THE EUROCODES DESIGNERS’ GUIDE TO EUROCODE 8: DESIGN OF STRUCTURES FOR EARTHQUAKE RESISTANCE 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 AND RETAINING STRUCTURES 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.P.Ross.0727731629.Forthcoming:2010(provisional). Designers’ Guide to EN 1991-4. Eurocode 1: Actions on Structures. Wind Actions. N. Cook. 0 7277 3152 1. Published2006. Designers’GuidetoEN1996.Eurocode6:Part1.1:DesignofMasonryStructures.J.Morton.0727731556. Forthcoming:2010(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.Published2007. Designers’GuidetoEN1993-2.Eurocode3:DesignofSteelStructures.Bridges.C.R.HendyandC.J.Murphy. 0727731602.Forthcoming:2010(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:2009(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:2009(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 EUROCODE 8: DESIGN OF STRUCTURES FOR EARTHQUAKE RESISTANCE 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 AND RETAINING STRUCTURES M. FARDIS, E. CARVALHO, A. ELNASHAI, E. FACCIOLI, P. PINTO and A. PLUMIER Series editor H. Gulvanessian PublishedbyThomasTelfordLimited,1HeronQuay,LondonE144JD,UK.www.thomastelford.com DistributorsforThomasTelfordLimitedare USA:ASCEPress,1801AlexanderBellDrive,Reston,VA20191-4400 Australia:DABooksandJournals,648WhitehorseRoad,Mitcham3132,Victoria Firstpublished2005 Reprinted2009 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 implementationprocesspleasevisitourwebsiteoremaileurocodes@thomastelford.com AcataloguerecordforthisbookisavailablefromtheBritishLibrary ISBN:978-0-7277-3348-1 #TheauthorsandThomasTelfordLimited2005 Allrights,includingtranslation,reserved.ExceptaspermittedbytheCopyright,DesignsandPatents Act1988,nopartofthispublicationmaybereproduced,storedinaretrievalsystemortransmittedin any form or by any means, electronic, mechanical, photocopying or otherwise, without the prior written permission of the Director, Knowledge Services, Thomas Telford Limited, 1 Heron Quay, LondonE144JD. 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. TypesetbyHelius,BrightonandRochester PrintedandboundinGreatBritainbyMPGBooks,Bodmin Color profile: Disabled Composite Default screen Preface Aim of this guide ThisDesigners’GuidetoEN1998-1andEN1998-5coverstherulesfortheseismicdesignof buildingsandfoundations,followingsinaloosewaythecontentsofthesetwoEurocodes. It summarizes the important points of these two Eurocodes without repeating them, and provides comments and explanations for their application, as well as background information.However,itdoesnotelaborateonallclausesofthesetwoEurocodes,neither doesitfollowstrictlythesequenceofclauses. Layout of this guide All cross-references in this guide to sections, clauses, subclauses, paragraphs, annexes, figures,tablesandexpressionsofEN1998-1andEN1998-5areinitalictype,whichisalso usedwheretextfromEN1998-1andEN1998-5hasbeendirectlyreproduced(conversely, quotationsfromothersources,includingotherEurocodes,andcross-referencestosections, etc.,ofthisguide,areinromantype).ExpressionsrepeatedfromEN1998-1andEN1998-5 retain their numbering; other expressions have numbers prefixed by D (for Designers’ Guide),e.g.equation(D3.1). Acknowledgements ThisguidewouldnothavebeenpossiblewithoutthesuccessfulcompletionofEN1998-1and EN1998-5.Thoseinvolvedintheprocesswere: (cid:127) NationaldelegatesandnationaltechnicalcontactstoSubcommittee8ofCEN/TC250. (cid:127) The three project teams of CEN/TC250/SC8 that worked for the conversion from the ENVstoENs,namelyPT1andPT2forEN1998-1,underthechairmanshipofCarlos Soussa Oliveira and Jack Bouwkamp, respectively, and PT3 for EN 1998-5, under the chairmanshipofEzioFaccioli. The very important technical contributions of Philippe Bisch within the framework of CEN/TC250/SC8deservesaspecialacknowledgement,andtheauthorswishtoexpresstheir gratitudeandappreciationforPhilippe’scontribution. Although not in the list of co-authors, Mauro Dolce of the University of Basilicata and LuigiDiSarnooftheUniversityofNapoliwhocontributedsignificantlytoChapters9and3, respectively.Theirhelpisgratefullyacknowledged. Amongtheco-authors,EzioFaccioliwishestoexpresshisgratitudetoStudioGeotecnico ItalianoinMilano,foritssupportinthepreparationofChapter10,andinparticulartothe following individuals who cooperated substantially in the preparation of the examples: A. 5 EN 1998-1 08 September 2005 12:24:42 Color profile: Disabled Composite Default screen DESIGNERS’GUIDETOEN1998-1ANDEN1998-5 Callerio(whoalsoassistedinthefinalpreparationofthefiguresandthetext),M.Redaelli, P.Ascari,andR.Andrighetto.HeislikewiseindebtedtoRobertoPaolucci,ofPolitecnicodi Milano,forprovidingvaluablematerialandfiguresontopographicamplificationandonthe seismicresponseandstabilityofshallowfoundationsinChapter10. vi 6 EN 1998-1 08 September 2005 12:24:42 Color profile: Disabled Composite Default screen Contents Preface v Aimofthisguide v Layoutofthisguide v Acknowledgements v Chapter1 Introduction 1 1.1. ScopeofEurocode8 1 1.2. ScopeofEurocode8–Part1 1 1.3. ScopeofEurocode8–Part5 2 1.4. UseofEurocode8–Parts1and5withtheotherEurocodes 2 1.5. Assumptions–distinctionbetweenPrinciplesandApplicationRules 3 1.6. Termsanddefinitions–symbols 3 Chapter2 Performancerequirementsandcompliancecriteria 5 2.1. PerformancerequirementsfornewdesignsinEurocode8and associatedseismichazardlevels 5 2.2. Compliancecriteriafortheperformancerequirementsandtheir implementation 7 2.2.1. Compliancecriteriafordamagelimitation 7 2.2.2. Compliancecriteriafortheno-(local-)collapse requirement 7 2.3. ExemptionfromtheapplicationofEurocode8 10 Chapter3 Seismicactions 13 3.1. Groundconditions 13 3.1.1. Identificationofgroundtypes 14 3.2. Seismicaction 15 3.2.1. Seismiczones 15 3.2.2. Basicrepresentationoftheseismicaction 18 3.2.3. Alternativerepresentationsoftheseismicaction 24 3.3. Displacementresponsespectra 27 Chapter4 Designofbuildings 31 4.1. Scope 31 4.2. Conceptionofstructuresforearthquakeresistantbuildings 31 4.2.1. Structuralsimplicity 31 7 EN 1998-1 08 September 2005 12:24:42 Color profile: Disabled Composite Default screen DESIGNERS’GUIDETOEN1998-1ANDEN1998-5 4.2.2. Uniformity,symmetryandredundancy 32 4.2.3. Bi-directionalresistanceandstiffness 32 4.2.4. Torsionalresistanceandstiffness 33 4.2.5. Diaphragmaticbehaviouratthestoreylevel 33 4.2.6. Adequatefoundation 34 4.3. Structuralregularityanditsimplicationsfordesign 34 4.3.1. Introduction 34 4.3.2. Regularityinplan 35 4.3.3. Regularityinelevation 41 4.4. Combinationofgravityloadsandotheractionswiththedesign seismicaction 43 4.4.1. Combinationforlocaleffects 43 4.4.2. Combinationforglobaleffects 43 4.5. Methodsofanalysis 44 4.5.1. Overviewofthemenuofanalysismethods 44 4.5.2. Thelateralforcemethodofanalysis 44 4.5.3. Modalresponsespectrumanalysis 48 4.5.4. Linearanalysisfortheverticalcomponentoftheseismic action 52 4.5.5. Non-linearmethodsofanalysis 53 4.6. Modellingofbuildingsforlinearanalysis 59 4.6.1. Introduction:thelevelofdiscretization 59 4.6.2. Modellingofbeams,columnsandbracings 60 4.6.3. Specialmodellingconsiderationsforwalls 61 4.6.4. Crackedstiffnessinconcreteandmasonry 62 4.6.5. Accountingforsecond-order(P-∆)effects 63 4.7. Modellingofbuildingsfornon-linearanalysis 64 4.7.1. Generalrequirementsfornon-linearmodelling 64 4.7.2. Specialmodellingrequirementsfornon-lineardynamic analysis 66 4.7.3. Theinadequacyofmembermodelsin3Dasalimitation ofnon-linearmodelling 68 4.8. Analysisforaccidentaltorsionaleffects 68 4.8.1. Accidentaleccentricity 68 4.8.2. Estimationoftheeffectsofaccidentaleccentricity throughstaticanalysis 69 4.8.3. Simplifiedestimationoftheeffectsofaccidental eccentricity 70 4.9. Combinationoftheeffectsofthecomponentsoftheseismic action 71 4.10. ‘Primary’versus‘secondary’seismicelements 72 4.10.1. Definitionandroleof‘primary’and‘secondary’seismic elements 72 4.10.2. Specialrequirementsforthedesignofsecondaryseismic elements 73 4.11. Verification 74 4.11.1. Verificationfordamagelimitation 74 4.11.2. Verificationfortheno-(local)-collapserequirement 75 4.12. Specialrulesforframesystemswithmasonryinfills 81 4.12.1. Introductionandscope 81 4.12.2. Designagainsttheadverseeffectsofplanwiseirregular infills 82 4.12.3. Designagainsttheadverseeffectsofheightwiseirregular infills 83 viii 8 EN 1998-1 08 September 2005 12:24:42 Color profile: Disabled Composite Default screen CONTENTS Chapter5 Designanddetailingrulesforconcretebuildings 85 5.1. Scope 85 5.2. Typesofconcreteelements-definitionof‘criticalregions’ 86 5.2.1. Beamsandcolumns 86 5.2.2. Walls 86 5.2.3. Ductilewalls:coupledanduncoupled 87 5.2.4. Largelightlyreinforcedwalls 88 5.2.5. Criticalregionsinductileelements 89 5.3. Typesofstructuralsystemsforearthquakeresistanceof concretebuildings 89 5.3.1. Inverted-pendulumsystems 90 5.3.2. Torsionallyflexiblesystems 90 5.3.3. Framesystems 90 5.3.4. Wallsystems 91 5.3.5. Dualsystems 91 5.3.6. Systemsoflargelightlyreinforcedwalls 91 5.4. Designconcepts:designforstrengthorforductilityandenergy dissipation-ductilityclasses 92 5.5. Behaviourfactorqofconcretebuildingsdesignedforenergy dissipation 93 5.6. Designstrategyforenergydissipation 95 5.6.1. Globalandlocalductilitythroughcapacitydesignand memberdetailing:overview 95 5.6.2. Implementationofcapacitydesignofconcreteframes againstplastichingingincolumns 96 5.6.3. Detailingofplastichingeregionsforflexuralductility 101 5.6.4. Capacitydesignofmembersagainstpre-emptiveshear failure 105 5.7. Detailingrulesforthelocalductilityofconcretemembers 111 5.7.1. Introduction 111 5.7.2. Minimumlongitudinalreinforcementinbeams 111 5.7.3. Maximumlongitudinalreinforcementratiointhecritical regionsofbeams 112 5.7.4. Maximumdiameteroflongitudinalbeambarscrossing beam-columnjoints 113 5.7.5. Verificationofbeam-columnjointsinshear 116 5.7.6. Dimensioningofshearreinforcementincriticalregions ofbeamsandcolumns 120 5.7.7. Confinementreinforcementinthecriticalregionsof columnsandductilewalls 123 5.7.8. Boundaryelementsatsectionendsinthecriticalregion ofductilewalls 127 5.7.9. Shearverificationinthecriticalregionofductilewalls 127 5.7.10. Minimumclampingreinforcementacrossconstruction jointsinwallsofDCH 130 5.8. Specialrulesforlargewallsinstructuralsystemsoflargelightly reinforcedwalls 131 5.8.1. Introduction 131 5.8.2. DimensioningfortheULSinbendingwithaxialforce 131 5.8.3. DimensioningfortheULSinshear 132 5.8.4. Detailingofthereinforcement 134 5.9. Specialrulesforconcretesystemswithmasonryorconcrete infills 135 5.10. Designanddetailingoffoundationelements 138 ix 9 EN 1998-1 08 September 2005 12:24:43 Color profile: Disabled Composite Default screen DESIGNERS’GUIDETOEN1998-1ANDEN1998-5 Chapter6 Designanddetailingrulesforsteelbuildings 141 6.1. Scope 141 6.2. Dissipativeversuslow-dissipativestructures 141 6.3. Capacitydesignprinciple 143 6.4. Designforlocalenergydissipationintheelementsandtheir connections 144 6.4.1. Favourablefactorsforlocalductility 144 6.4.2. Unfavourablefactorsforlocalductility 145 6.5. Designrulesaimingattherealizationofdissipativezones 146 6.6. Backgroundofthedeformationcapacityrequiredby Eurocode8 147 6.7. Designagainstlocalizationofstrains 148 6.8. Designforglobaldissipativebehaviourofstructures 150 6.8.1. Structuraltypesandbehaviourfactors 150 6.8.2. Selectionofthebehaviourfactorfordesignpurposes 151 6.9. Moment-resistingframes 152 6.9.1. Designobjective 152 6.9.2. Analysisissuesinmoment-resistingframes 152 6.9.3. Designofbeamsandcolumns 153 6.9.4. Designofdissipativezones 156 6.9.5. Limitationofoverstrength 157 6.10. Frameswithconcentricbracings 158 6.10.1. Analysisofframeswithconcentricbracingsconsidering theirevolutivebehaviour 158 6.10.2. SimplifieddesignofframeswithXbracings 159 6.10.3. Simplifieddesignofframeswithdecoupleddiagonal bracings 159 6.10.4. SimplifieddesignofframeswithVbracings 160 6.10.5. Criterionfortheformationofaglobalplasticmechanism 160 6.10.6. Partialstrengthconnections 160 6.11. Frameswitheccentricbracings 161 6.11.1. Generalfeaturesofthedesignofframeswitheccentric bracings 161 6.11.2. Shortlinksversuslonglinks 162 6.11.3. Criteriatoformaglobalplasticmechanism 163 6.11.4. Selectionofthetypologyofeccentricbracings 164 6.11.5. Partialstrengthconnections 164 6.12. Moment-resistingframeswithinfills 165 6.13. Controlofdesignandconstruction 165 Chapter7 Designanddetailingofcompositesteel-concretebuildings 167 7.1. Introductoryremark 167 7.2. Degreeofcompositecharacter 167 7.3. Materials 168 7.4. Designforlocalenergydissipationinelementsandtheir connections 168 7.4.1. Favourablefactorsforlocalductilityduetothe compositecharacterofstructures 168 7.4.2. Unfavourablefactorsforlocalductilityduetothe compositecharacterofstructures 169 7.5. Designfortheglobaldissipativebehaviourofstructures 170 7.5.1. Behaviourfactorsofstructuraltypessimilartosteel 170 7.5.2. Behaviourfactorsofcompositestructuralsystems 171 x 10 EN 1998-1 08 September 2005 12:24:43