简介:Objectivesofthistaskaretoconductresearchonseismichazards,andtoproviderelevantinputontheexpectedlevelsofthesehazardstoothertasks.Othertasksrequiringthisinputincludethosedealingwithinventory,fragilitycurves,rehabilitationstrategiesanddemonstrationprojects.Thecorrespondinginputisprovidedinvariousformatsdependingontheintendeduse:aspeakgroundmotionparametersand/orresponsespectralvaluesforagivenmagnitude,epicentraldistanceandsiteconditions;orastimehistoriesforscenarioearthquakesthatareselectedbasedonthedisaggregatedseismichazardmappedbytheU.S.GeologicalSurveyandareincorporatedinbuildingcodes.Theusercommunityforthisresearchisbothacademicresearchersandpracticingengineerswhomayusetheseismicinputgeneratedbythesynthesistechniquesthataredevelopedunderthistaskforavarietyofapplications.Theseincludegroundmotionsforscenarioearthquakes,fordevelopingfragilitycurvesandinspecifyinggroundmotioninputforcriticalfacilities(suchashospitals)locatedintheeasternU.S.
简介:Thecomputationoftherepresentativegroundmotions,tobeusedasinputforthedynamicanalysesofastruc-tureataparticularsite,canbeapproachedbyseveralmethods.Thechoiceoftheapproachdependsontwofactors:theda-taavailableandthetypeofproblemtobesolved.Thispaperreportstheexperienceoftheauthorsinapproachingaspecificcasestudy:theSouthernMemnonColossus,locatedinLuxor,Egypt.Theresultsareofinterestwhenthehazardanalysisestimationindevelopingcountriesandthesafeguardofculturalheritageareconcerned.Monumentshavetobetreatedasimportantstructures,duetotheirhistoricalandeconomicalvalue.Hence,standardproceduresofprobabilisticseismichaz-ardanalysisfortheseismicclassificationofcommonbuildingshavetobedisregarded.Ontheotherhand,theconsequencesofthecollapseofamonumentarenotcomparabletothoserelatedtostructuressuchasnuclearpowerplantsandlargedams,forwhichthedeterministicseismichazardanalysisprovidesastraightforwardframeworkforevaluationoftheworstcaseone,isadopted.Itsstochasticcomponentcancapturesignificantcharacteristicsofearthquakes,primarilythefrequencycontentswhichdependonthemagnitude(oftenreferredtoastheearthquakescalinglaw).
简介:Ingeneral,theseismicresponseanalysisinearthquakeengineeringassumesthatthevibrationparametersofthetargetandthecontactsurfaceoftheexternalmediaareidentical,i.e.,singlepointinput.However,earthquakeenergyhasanattenuationphenomenoninwavepropagation,soawiderangeofsoilslopesandtheexternalmediumcontactsurfaceofdifferentinputpointsonmotionarenotidentical.Ifweconsidersinglepointinputonly,itmaynotcorrespondwithreality,soitisnecessarytocarryoutresearchonmulti-pointinputmethods.Basedonthe2-Dslopemodel,single-pointinputandmulti-pointinputareperformedrespectivelytoanalyzeandcomparetheirsimilaritiesanddifferencesintheperspectivesofthecharacteristicsofseismicresponseofsoillayerandplasticzonedistributiontoprovideareferencefortheseismicdesignofslopes.Theresultsshowthatintheperspectiveofsoilseismicresponseanalysis,thepeakaccelerationoutputandpeakvelocityoutputundermulti-pointinputaregreaterthanthepeakvaluesundersinglepointinputatthesamemonitoringpoint,thepeakappearingtimeisalsoearlierthanthatofthesinglepointinput;intermsoftheplasticzonedistribution,themulti-pointeffectismanifestedasthepresenceofmoreobvioustensileshearfailures;intheperspectiveofsafetycoefficient,thesafetycoefficientundereachmulti-pointinputissmallerthanthatofsinglepointinput,adifferenceofabout7%orso.Insummary,multi-pointinputismorereasonableandpracticalthansinglepointinput,somulti-pointinputshouldbeconsideredinseismicdesign.
简介:为波浪繁殖建模的一个新方法在这份报纸被介绍。由使用限制优化(Lagrange更多样地)方法,当使遭到了到限制时,加权的摆平的Fourier振幅的和被最小化。从所有产量模型获得的最大的振幅的和被规范化为统一并且作为限制被拿。在这个方法,所有实际时间历史被看作产量并且同等地处理了。独立于时间历史的联合(或选择的第一次历史)在分析期间,方法捕获由出现的历史清除山峰的实际时间的关系。这份报纸描述模型的明确的表达并且在规范的输入产量最小化(NIOM)上说明这个方法的优点方法。Mod-NIOM然后被用来分析在科比在端口岛垂直数组地点记录的Hyogoken-nanbu地震的时间历史,它受不了强壮的运动在主要吃惊期间引起的液化。尽管表面时间历史被液化极大地修改,这个方法在这个地点显示出在观察时间历史之间的好关联。