简介：AsimplifiedfragilityanalysisoffantypecablestayedbridgesusingProbabilisticRiskAnalysis(PRA)procedureispresentedfordeterminingtheirfailureprobabilityunderrandomgroundmotion.Seismicinputtothebridgesupportisconsideredtobeariskconsistentresponsespectrumwhichisobtainedfromaseparateanalysis.Fortheresponseanalysis,thebridgedeckismodeledasabeamsupportedonspringsatdifferentpoints.Thestiffnessesofthespringsaredeterminedbyaseparate2Dstaticanalysisofcable-tower-decksystem.Theanalysisprovidesacoupledstiffnessmatrixforthespringsystem.Acontinuummethodofanalysisusingdynamicstiffnessisusedtodeterminethedynamicpropertiesofthebridges.Theresponseofthebridgedeckisobtainedbytheresponsespectrummethodofanalysisasappliedtomultidegreeoffreedomsystemwhichdulytakesintoaccountthequasi-staticcomponentofbridgedeckvibration.Thefragilityanalysisincludesuncertaintiesarisingduetothevariationingroundmotion,materialproperty,modeling,methodofanalysis,ductilityfactoranddamageconcentrationeffect.ProbabilityoffailureofthebridgedeckisdeterminedbytheFirstOrderSecondMoment(FOSM)methodofreliability.Athreespandoubleplanesymmetricalfantypecablestayedbridgeoftotalspan689m,isusedasanillustrativeexample.Thefragilitycurvesforthebridgedeckfailureareobtainedunderanumberofparametricvariations.Someoftheimportantconclusionsofthestudyindicatethat(i)notonlyverticalcomponentbutalsothehorizontalcomponentofgroundmotionhasconsiderableeffectontheprobabilityoffailure;(ii)groundmotionwithnotimelagbetweensupportexcitationsprovidesasmallerprobabilityoffailureascomparedtogroundmotionwithverylargetimelagbetweensupportexcitation;and(iii)probabilityoffailuremayconsiderablyincreaseforsoftsoilcondition.

简介：Inthispaper,anewhybridcontroltechnique,basedonacombinationofbase-isolationandsemi-activevariablestiffness/dampinginasuperstructure,ispresented.Toillustratetheefficiencyoftheproposedcontrolsystem,modeltestsonamini-electromagneticshakingtableandanumericalsimulationwereperformed.Thetestandnumericalcalculationresultsindicatethatthisnewhybridcontrolmodewithadditionaldampingandsmalleradditionalstiffnesscanachieveabettercontrolefficiency.

简介：Theauthorsproposedamethodforobtaininghigh-qualityaccelerationseismogramsfromvelocitytypeseismogramsofdigitalSeismographicnetwork,andtookasanexampletheanalysisandprocessingoftheseismogramsofasameearthquakethatwassimultaneouslyrecordedbyvelocityseismographCTS1-EDAS24andstrongmotionseismographEST-Q4128installedinJixianStation,Tianjin.Thecalculationstepsandtheprocessingmethodhavebeendiscussedindetail.Fromtheanalysisandthecomparisonoftheobtainedresults,itisconcludedthattheproposedmethodissimpleandeffective,anditbroadenstheapplicationofdigitalseismographicnetwork.

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