简介:Addingdampersisacommonlyadoptedseismicriskmitigationstrategyformodernbuildings,andthecorrespondingdesignprocedureofdampershasbeenwellestablishedbytheChineseBuildingCode.Eventhoughalltypesofdampersaredesignedbythesameprocedure,actualseismicperformanceofthebuildingmaydifferfromonetotheothers.Inthisstudy,anine-storybenchmarksteelbuildingisestablished,andthreedifferentandtypicaltypesofdampersaredesignedaccordingtotheChineseBuildingCodetorealizestructuralvibrationcontrolunderstrongearthquakeexcitation.Theseismicresponseoftheprototypebuildingequippedwithaviscoelasticdamper,viscousdamperandbuckling-restrainedbrace(BRB)subjectedto10earthquakerecordsarecalculated,andIncrementalDynamicAnalysis(IDA)isperformedtodescribeprogressivedamageofthestructureunderincreasingearthquakeintensity.Intheperspectiveoffragility,itshowsthattheviscoelasticdamperhasthehighestcollapsemarginratio(CMR),andtheviscousdamperprovidesthebestdriftcontrol.BoththeBRBandviscoelasticdamperscaneffectivelyreducetheflooraccelerationresponsesinthemid-risebuilding.
简介:UnreinforcedMasonry(URM)isthemostcommonpartitioningmaterialinframedbuildingsinIndiaandmanyothercountries.Althoughitiswell-knownthatunderlateralloadingthebehaviorandmodesoffailureoftheframebuildingschangesignificantlyduetoinfill-frameinteraction,thegeneraldesignpracticeistotreatinfillsasnonstructuralelementsandtheirstiffness,strengthandinteractionwiththeframeisoftenignored,primarilybecauseofdifficultiesinsimulationandlackofmodelingguidelinesindesigncodes.TheIndianStandard,likemanyothernationalcodes,doesnotprovideexplicitinsightintotheanticipatedperformanceandassociatedvulnerabilityofinfilledframes.ThispaperpresentsananalyticalstudyontheseismicperformanceandfragilityanalysisofIndiancode-designedRCframebuildingswithandwithoutURMinfills.InfillsaremodeledasdiagonalstrutsasperASCE41guidelinesandvariousmodesoffailureareconsidered.HAZUSmethodologyalongwithnonlinearstaticanalysisisusedtocomparetheseismicvulnerabilityofbareandinfilledframes.ThecomparativestudysuggeststhatURMinfillsresultinasignificantincreaseintheseismicvulnerabilityofRCframesandtheireffectneedstobeproperlyincorporatedindesigncodes.
简介:Buildingcodeshavewidelyconsideredtheshearwavevelocitytomakeareliablesubsoilseismicclassification,basedontheknowledgeofthemechanicalpropertiesofmaterialdepositsdowntobedrock.Thisapproachhaslimitationsbecausegeophysicaldataareoftenveryexpensivetoobtain.Recently,otheralternativeshavebeenproposedbasedonmeasurementsofbackgroundnoiseandestimationoftheH/Vamplificationcurve.However,theuseofthistechniqueneedsaregulatoryframeworkbeforeitcanbecomearealisticsiteclassificationprocedure.ThispaperproposesanewformulationforcharacterizingdesignsitesinaccordancewiththeAlgerianseismicbuildingcode(RPA99/ver.2003),throughtransferfunctions,byfollowingastochasticapproachcombinedtoastatisticalstudy.Foreachsoiltype,thedeterministiccalculationoftheaveragetransferfunctionisperformedoverawidesampleof1-Dsoilprofiles,wheretheaverageshearwave(S-W)velocity,Vs,insoillayersissimulatedusingrandomfieldtheory.Averagetransferfunctionsarealsousedtocalculateaveragesitefactorsandnormalizedaccelerationresponsespectratohighlighttheamplificationpotentialofeachsitetype,sincefrequencycontentofthetransferfunctionissignificantlysimilartothatoftheH/Vamplificationcurve.ComparisonisdonewiththeRPA99/ver.2003andEurocode8(EC8)designresponsespectra,respectively.Intheabsenceofgeophysicaldata,theproposedclassificationapproachtogetherwithmicro-tremormeasurescanbeusedtowardabettersoilclassification.
简介:ThispaperpresentsacomparisonbetweentheChineseCodeGB50011-2001andtheInternationalStandardISO3010:2001(E),emphasizingthesimilaritiesanddifferencesrelatedtodesignrequirements,seismicactionsandanalyticalapproaches.Similaritiesinclude:earthquakereturnperiod,conceptualdesign,siteclassification,structuralstrengthandductilityrequirements,deformationlimits,responsespectra,seismicanalysisprocedures,isolationandenergydissipation,andnonstructuralelements.Differencesexistinthefollowingareas:seismiclevels,earthquakeloading,modedampingfactorsandstructuralcontrol.