简介:一种普通情形在象地震那样的灾难期间是地点上的损坏地侦察的活动是不协调得好的。例如在意大利,对在地震以后的结构的损坏评价从意大利的紧急情况权威被管理,用被产生在填写并且转到灾难管理起作用的中心的表格的很多混乱的地点上的专家填写的打印表格(豹脚蚊)。因为这,论文探索使用活动通讯技术(聪明的电话)和网开发将在主要灾难以后帮助社区的反应系统的生存能力,提供为允许上载并且散布信息的居民和应答者的隧道,与协调损坏域侦察的结构的损坏有关。能被居民在聪明的电话上运用的一个活动应用程序被开发了,到当时,给起始的损坏区域的评估,它将很有用资源(例如专家的数字被限制)。活动应用程序在2012Emilia地震期间第一次被测试了提高紧急情况反应,显示出在把建议过程与标准过程作比较的统计术语的建议方法的效率。
简介:Thewindenergyindustryhasbeengrowingrapidlyduringthepastdecades.Alongwiththisgrowth,engineeringproblemshavegraduallyemergedinthewindpowerindustry,includingthoserelatedtothestructuralreliabilityofturbinetowers.Thisstudyproposesarapidseismicanalysismethodologyforexistingwindturbinetowerstructures.Themethodisdemonstratedandvalidatedusingacasestudyona1.5MWtubularsteelwindturbinetower.Threefiniteelement(FE)modelsaredevelopedfirst.Fieldtestsareconductedtoobtaintheturbinetower’svibrationalcharacteristics.Thetestsinclude(1)remotelymeasuringthetowervibrationfrequenciesusingalongrangelaserDopplerVibrometerand(2)monitoringthetowerstructuralvibrationbymountingaccelerometersalongtheheightofthetubularstructure.In-situmeasurementsareusedtovalidateandupdatetheFEmodelsofthewindturbinetower.WiththeupdatedFEmodelthatrepresentsthepracticalstructuralconditions,seismicanalysesareperformedtostudythestructuralfailure,whichisdefinedbythesteelyieldingofthetubulartower.Thisresearchisanticipatedtobenefitthemanagementoftheincreasingnumberofwindenergyconvertersbyprovidinganunderstandingoftheseismicassessmentofexistingtubularsteelwindturbinetowers.
简介:AnindexingmethodforrapidevaluationoftheseismicvulnerabilityofinfilledRCframebuildingsinJordanisproposed.Themethodaimsatidentifyinglowandmediumriseresidentialbuildingsassafeorinneedoffurtherdetailedevaluation.Followingarapidvisualscreening,thebuildingisassignedaBasicCapacityIndex(BCI);fiveperformancemodifiersareidentifiedandmultipliedbytheBCItoarriveattheCapacityIndex(CI)ofthebuilding.ACapacityIndexlowerthanalimitCIvalueindicatesthatthescreenedbuildingcouldexperiencemoderateearthquakedamagewhereasahighervalueimpliesthatminordamage,ifany,wouldtakeplace.Toestablishthebasicevaluationparameters;fortyRCframebuildingswereselected,designedandanalyzedusingstaticnonlinearanalysisandincorporatingtheeffectofinfillwalls.Effectsofseismicity,localsiteconditions,horizontalirregularities(setbacksandre-entrantcorners),verticalirregularities(softstoryatgroundfloorlevel)andoverhangsontheseismicperformanceoflocalbuildingswereexamined.Assessmentformsweredesignedandusedtoevaluateandrank112samplebuildings.About40%ofthesurveyedbuildingswerefoundtobeinneedofdetailedevaluationtobetterdefinetheirseismicvulnerabilities.
简介:Wesuccessfullyemployanautomaticcentroidmomenttensor(CMT)inversionsystemtoinfertheCMTsolutionsoftheFebruary12,2014MS7.3Yutian,Xinjiangearthquakeusingnear-fieldseismicwaveforms(4°<△<12°)observedbythevirtualChinaseismicnetworks,whichhavebeenrecentlysetup.Theresultsindicatethatthiseventoccurredonaruptureplane(strike243°,dip70°,andrake-18°),showingleft-lateralstrike-slipfaultingwithaminornormal-faultingcomponent.Thecentroidinthehorizontaldirectionislocatednearly13kmeastoftheepicenter(36.123°N,82.499°E),andthebest-fittingcentroiddepthisaround10km.Thetotalscalarmoment,M0,isretrievedwithanaveragevalueof3.05×1019N·m,correspondingtomomentmagnitudeMW6.92.Mostoftheenergyisreleasedwithinabout14s.Moreover,wediscussaboutthepotentialapplicationofthissysteminearthquakedisasterdecision.
简介:Inthisstudy,threerapidrepairtechniquesareproposedtoretrofitcircularbridgepiersthatareseverelydamagedbytheflexuralfailuremodeinmajorearthquakes.Thequasi-statictestsonthree1:2.5scaledcircularpierspecimensareconductedtoevaluatetheefficiencyoftheproposedrepairtechniques.Forthepurposeofrapidrepair,therepairprocedureforallthespecimensisconductedwithinfourdays,andthebehavioroftherepairedspecimensisevaluatedandcomparedwiththeoriginalones.Afiniteelementmodelisdevelopedtopredictthecyclicbehavioroftherepairedspecimensandthenumericalresultsarecomparedwiththetestdata.Itisfoundthatalltherepairedspecimensexhibitsimilarorlargerlateralstrengthanddeformationcapacitythantheoriginalones.Theinitiallateralstiffnessofalltherepairedspecimensislowerthanthatoftheoriginalones,whiletheyshowahigherlateralstiffnessatthelaterstageofthetest.Nonoticeabledifferenceisobservedfortheenergydissipationcapacitybetweentheoriginalandrepairedpierspecimens.Itissuggestedthattherepairtechniqueusingtheearly-strengthconcretejacketconfinedbycarbonfiberreinforcedpolymer(CFRP)sheetscanbeanoptimalmethodfortherapidrepairofseverelyearthquake-damagedcircularbridgepierswithflexuralfailuremode.
简介:Significantpostseismicdeformationofthe2008MW7.9WenchuanearthquakehasbeenobservedfromGPSdataofthefirst14daysaftertheearthquake.Thepossiblemechanismsfortherapidpostseismicdeformationareassumedtobeafterslipontheearthquakeruptureplaneandviscoelasticrelaxationofcoseismicllystresschangeinthelowercrustoruppermantle.WefirstlyusetheconstrainedleastsquaresmethodtofindanafterslipmodelwhichcanfittheGPSdatabest.Theafterslipmodelcanexplainnear-fielddataverywellbutshowsconsiderablediscrepanciesinfittingfar-fielddata.Toestimatetheeffectduetotheviscoelasticrelaxationinthelowercrust,wethenignorethecontributionfromtheafterslipandattempttoinverttheviscositystructurebeneaththeLongmenshanfaultwheretheWenchuanearthquakeoccurredfromthepostseismicdeformationdata.Forthispurpose,weuseaviscoelasticmodelwitha2DgeometrybasedonthegeologicalandseismologicalobservationsandthecoseismicslipdistributionderivedfromthecoseismicGPSandInSARdata.Bymeansofagridsearchwefindthattheoptimumviscosityis9×1018Pa·sforthemiddle-lowercrustintheChengduBasin,4×1017Pa·sforthemiddle-lowercrustintheChuanxiPlateauand7×1017Pa·sforthelowvelocityzoneintheChuanxiplateau.Theviscoelasticmodelexplainsthepostseismicdeformationobservedinthefar-fieldsatisfactorily,butitisconsiderablyworsethantheafterslipmodelinfittingthenear-faultdata.Itsuggeststhereforeahybridmodelincludingbothafterslipandrelaxationeffects.Sincetheviscoelasticmodelproducesmainlythefar-fieldsurfacedeformationandhasfewerdegreeoffreedoms(threeviscosityparameters)thantheafterslipmodelwithahugenumberofsourceparameters,wefixtheviscositiystructureasobtainedbeforebutredeterminetheafterslipdistributionusingtheresidualdatafromtheviscoelasticmodeling.Theredeterminedafterslipdistributionbecomesphysicallymorereas