钢木混合结构多层建筑开发

ZhengLiPhD,AssistantProfessorDepartmentofStructuralEngineeringTongjiUniversitySeismicPerformanceofTimber-SteelHybridStructuresTheFifthTongji-UBCSymposiumonEarthquakeEngineering"FacingEarthquakeChallengesTogether”Outline1.Introduction2.Timber-steelhybridstructure3.Experimentalstudy4.Numericalmodeling5.Reliabilityanalysis6.Summary1.IntroductionEarthquakes!1.IntroductionChristchurchearthquake,M6.3,NewZealand,2011,PhotobyA.TraffordWenchuanearthquake,M8.0,China,2008Wenchuanearthquake,M8.0,China,2008Kobeearthquake,M6.9,Japan,1995,PhotobyM.YasumuraMurrayGrove8-storeyCLTstructureinLondon(2008)10-storeyCLTstructureinMelbourne(2012)Timber-concretehybridbuildinginQuebecCity(2010)Examplesofmulti-storeytimberbuildings1.Introduction2.Formationoftimber-steelhybridstructureWhynothybridization?Hybridizationcanbeanalternativetodevelopmulti-storeytimberbuildings,becauseitnormallycombinestherespectivebenefitsofdifferentmaterials.Inthisproject,akindofmulti-storeytimber-steelhybridstructureisproposed.Timber-steelhybridstructureTimberhybriddiaphragmSteelmomentresistingframeSuitableformulti-storybuildingsGoodseismicperformanceHigherdegreeofindustrializationAdvantagesLightwood-framedshearwallHorizontalsystemVerticalsystemSteelframeInfillwood-framedshearwallBoltsAnchorboltsHold-down

Timber-steelhybridshearwallsystem2.Formationoftimber-steelhybridstructureSpecimenA:lightwood-frameddiaphragmsingle-sheathedinfillwood-framedshearwallSpecimenB:Timber-steelhybriddiaphragmdouble-sheathedinfillwood-framedshearwallA-1,A-2,A-3andB-1,B-2,B-3aretimber-steelhybridshearwallsystemsinspecimenAandspecimenB.3.1Specimendesign3.ExperimentalstudyLayoutofspecimenAandspecimenBSpecimenA(lightwood-frameddiaphragm&single-sheathedinfillwoodshearwall)SpecimenB(timber-steelhybriddiaphragm&double-sheathedinfillwoodshearwall)3.Experimentalstudy3.3InstallationofthespecimenThespecimenswerefirstsubjectedtonon-destructivemonotonicloadtostudytheinitiallateralstiffnessofthesteelframebeforeandaftertheinstallationofinfills.Thenfullyreversedquasi-staticcyclicloadwasappliedandcycledto80%ofdegradationinthespecimen’sstrength.3.Experimentalstudy3.4TestProceduresNailheadsembeddingintothesheathingpanelsFailureofweldFailuremodes3.ExperimentalstudyAfterthetestsFatiguefractureofnailsFalloffofthesheathingpanels(a)A-1(c)A-3(b)

A-2Hysteresisloops(d)B-1(f)B-3(e)B-23.ExperimentalstudyShareofforcebetweentimberandsteelInatimber-steelhybridsystem,thelateralloadwasresistedbythesteelframeandtheinfillwoodshearwallsimultaneously.Foreachspecimen,theshearforcescarriedbythetwosubsystemswereobtainedrespectively.Forinstance,theshearforcecarriedbythesteelframeandtheinfillwoodshearwallofA-2areshownbelow.3.ExperimentalstudyShareofforcebetweentimberandsteelBasedonthetestresultsoftheshearforcecarriedbyeachsubsystem,thepercentageshearforceofeachsubsystemcouldbeobtained.Intheinitialloadingstage(within25mm).Thesingle-anddouble-sheathedinfillwoodshearwallscarried50-75%and65-95%ofthelateralloadofthehybridsystem;Whendamagesoccurredinthewoodshearwalls,thepercentageshearforceinthewoodshearwallsdecreased,andthesteelframebecamemoreactive.Percentageshearforceinthesubsystems:(a)specimenwithsingle-sheathedinfilllightwood-framedshearwalls;(b)specimenwithdouble-sheathedinfilllightwood-framedshearwalls3.ExperimentalstudyNumericalmodel–timber-steelhybridshearwall4.NumericalmodelingUserdefinedelementinABAQUS4.NumericalmodelingModelvalidation4.NumericalmodelingLoad–displacementrelationshipEnergydissipationsDamageassessment5.ReliabilityanalysisTestsetupBackbonecurvesPerformancelevelImmediateoccupancy(IO)Lifesafety(LS)Collapseprevention(CP)Driftlimit(%)0.72.55.05.ReliabilityanalysisBaselinewalls:5.ReliabilityanalysisEarthquakeinput:AccordingtoChinesecodeof“Seismicdesignofbuildingstructures”,theprobabilitiesof50-yearexceedancefortheearthquakesconsideredintheIO,LS,andCPlimitstatesare63%,10%and2%,whichareinaccordancewiththeaveragereturnperiodof50,475,and2475years.NO.EventDateStationComponentPGA(g)1Wenchuan12/05/2008WolongEW0.9762Tangshan28/071976BeijingHotelEW0.0673Ninghe25/11/1976TianjinHospitalNS0.1494Qian’an31/08/1976M0303QiananlanhebridgeNS0.1355Chichi-121/09/1999CHY006NS0.3456Chichi-221/09/1999TCU070EW0.2557Chichi-321/09/1999TCU106NS0.1288Chichi-421/09/1999TAP052NS0.1279Kobe17/01/19950KJMAKJM0000.82110Northridge-117/01/19940013BeverlyHills-14145MulholMUL0090.41611Northridge-217/01/199424278Castaic-OldRidgeRouteORR0900.56812Northridge-317/01/199490086BuenaPark-LaPalmaBPK0900.13913LomaPrieta-118/10/198947381GilroyArray#3G030000.55514LomaPrieta-218/10/198957425GilroyArray#7GMR0000.22615LomaPrieta-318/10/198958224Oakland-Title&TrustTIB1800.1955.ReliabilityanalysisHybridshearwallwithKr=0.5HybridshearwallwithKr=1.0HybridshearwallwithKr=2.5HybridshearwallwithKr=5.0FragilityanalysisResponsesurfacemethod5.ReliabilityanalysisStep1.LimitstatefunctionStep2.ResponsesurfacegenerationbynumericalsimulationswhereKr

isashearwalldesignfactor15Spectrumlevels(0.10,0.16,0.30,0.45,0.60,0.75,0.90,1.05,1.20,1.35,1.50,1.65,1.80,2.05and2.10g)4Kr

levels(i.e.0.5,1.0,2.5,and5.0)15historicalearthquakerecords5.ReliabilityanalysisStep3.ResponsesurfacefittingbypolynomialfunctionsStep4.FailureprobabilityestimationProbabilistic-baseddesign5.ReliabilityanalysisPerformancecurvesforthehybridshearwallwithKr

=2.5Forthehybridshearwallsystem,theinfil