地震工程学-8 建筑物震害的工程控制

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1、第八章建筑物震害的工程控制地震灾害一、直接灾害地表破坏建筑物或构筑物破坏山体等自然物破坏二、次生灾害滑坡次生火灾水灾毒气泄漏瘟疫海啸…地震灾害的减灾、防灾单体城市结构抗震结构控制生命线城市设计系统规划被动半主动主动DevelopmentofseismicdesignmethodSimilartoMassstiffnessplasticitypassivecontrolactivecontrolwindeffectNewconcept:damagecontrolledstructureDesignseismicactioninUBC•BaseshearCI2.5CI

2、vaV=W0.11CIW≤V≤WaRTR•w—weight；•I—importancefactor；•C、C—Seismiccoefficient(acceleration,avvelocity)；•R—Seismicresponsemodificationcoefficient。RfactorsforSelectedSteelSystems(ASCE7):•SMF(SpecialMomentResistingFrames):R=8•IMF(IntermediateMomentResistingFrames):R=4.5•OMF(OrdinaryMomentRes

3、istingFrames):R=3.5•EBF(EccentricallyBracedFrames):R=8or7•SCBF(SpecialConcentricallyBracedFrames):R=6•OCBF(OrdinaryConcentricallyBracedFrames):R=3.25•BRBF(BucklingRestrainedBracedFrame):R=8or7•SPSW(SpecialPlateShearWalls):R=7•UndetailedSteelSystemsinSeismicDesignCategoriesA,BorCR=3(AI

4、SCSeismicProvisionsnotneeded)SeismicDesignPhilosophySEAOCBlueBook(1959):NonstructuralStructuralDamageDamageMinorNoNoEarthquakeModerateYesNoEarthquakeMajorYesYesEarthquake(ButNoCollapse)7EarthquakeObservationDuctilityHelps.VbEF3F2F1SStoryDrift,Δ8ResorttoDUCTILITY(orTradeDuctilityforS

5、trength)12DuctilityFactorBaseShear,VV=eDuctilityFactorΔW(S)aMΔmµ=×1/KΔyKRµVyΔΔyΔeΔm13SeismicDesignConcept1-DuctilityDesign•AReducedDesignSeismicForceCanBeUsedIFSufficientDuctilityIsBuiltintotheStructure•ButOnlyCertainElementsAreStrategicallyDesignatedtoServeasStructuralFuse,i.e.,Defor

6、mation-ControlledElements(DCE)14Example(SMF)•MainlyBeamsasStructuralFusethroughPlasticHingeFormation•PZandColumnBaseAlsoExpecttoYield•StrongColumn-WeakBeamConcept15Example(SCBF)•DiagonalBracesasStructuralFuse•BracesGenerallyDesignedtoBuckleOut-of-Plane•ToAchieveThis,MoreEffortIsNeeded

7、toMakeItHappen!16Example(EBF)•LinksasStructuralFuse•ShearYieldingPreferred17SeismicDesignConcept2-CapacityDesign•RemainingPartoftheStructureIsDesignedtoRemainElastic,i.e.,DesignTheseElementsasForce-ControlledElements(FCE).18TargetYieldMechanismMomentConcentricallyEccentricallyFrameBra

8、cedFr