简介: Introduction Withrapiddevelopmentandadvancementofeconomyandsociety,lotsofcitygroupsorcitybeltswithex-tra-largecitiesastheircentershavebeenformedinChina.Theregionsthesecitygroupslieinusuallyhavewell-developedeconomy,densepopulation,andareregionalpoliticsandculturecenters.Somegroupslieintheregionswithhighlevelofearthquakeactivity,suchastheSurroundingCapitalCityGroupwiththecentersofBei-jingandTianjin.Oncealargeearthquakeoccurs,itsinfluencewillspreadtoveryextensiveregionanditsdisasterwillbetremendoustoo.Soearthquakeresistanceanddisastermitigationofcitygroupwillbeverysignificantissue.Thecitiesinagrouphaveclosedistancewitheachother;theycancarryoutunifiedpreparationfordisasterasonewholeandreducetheheavyloadofsinglecitybeforeanearthquake,andhaveanadvantageofpromptmutual-aidafteranearthquakebecauseofclosedistance.Itisespeciallysignificanttomitigatetheloseoflives.Oneimportantpreconditionisthatallthecitiesinonegroupcannotbeexposedtothesamelevelofdestroyduringoneearth-quake.Sothedivisionofcitygroupintheregionwithdensecitiesdistributionshallbeverysignificanttotheemergentmutual-aidinearlytimeafteralargeearthquake.Forthisgoal,thecharacteristicsandcorrelativityofearthquake′simpactoncitiesinonegroupneedtoclearlybeconsidered.Thecitieswithsimilarfeaturesandstrongcorrelativityofhistoricalearthquakeinfluencehavelargechancetosuffersameleveldestroyduringthefuturestrongearthquakeandaredisadvantagetoprovidemutual-aidandshallnotbedividedintoonegroup. ……
简介:TheemergenceofZhangHeng’sseismoscopehasaprofoundhistoricalbackground.ThispaperintendstoexploretheformationandmaterialbasisofZhangHeng’sscientificthought.Itappearsthatthesimpleintentionof"observingvisionsanddistinguishinggoodfortuneormisfortune"washismotivationtodeveloptheseismoscope.Tracingitshistoricalbackground,theauthorsproposedinthispaperthatthedevelopmentofthisseismoscopestartedaround128A.D.,andbasedonperceptualknowledge,twoideasaboutearthquakescameintobeing,i.e.,earthquakelocationcouldbejudgedaccordingtotheinstrumentshakingdirection,andtheearthquakeandearthsplitwereessentiallydifferent.Intheinstrumentmanufacture,ZhangHengadvocatedaprincipleof"makingutensilstoimitatecosmos".Bythisprinciple,thefollowingthreeproblemswerereadilysolved:theseismoscopeimitatedtheresponseofthesuspensionsystemtoearthquakes(i.e.naturalseismoscope).Technically,thetriggermechanismofthelatchwasusedforreference,anditrecordedthephysicalevidenceofearthquakeoccurrencebyaningeniouswayofaballdroppingfromadragon’smouth.Thesolutionofthesethreekeyproblemsleadtotheemergenceoftheseismoscopein132A.D.andthesuccessfuldetectionofanearthquakein134A.D.Hisinventiondeepenedhumanity’sknowledgeofnaturallaws,andpromotedthedevelopmentofscienceandtechnologyinthattimeandlater.
简介:In2004,China’sdigitalseismicobservationnetworkprojectbegantodeploy40setsYRY-4four-componentboreholestrainmetersinordertomonitorearthquakepreparationprocess.Thepaperdescribesobservedsolidtidalstraindiscretenessandtidalfactoranisotropy,analyzesthereliabilityofobservationaldataanddiscussesthecauseforthisphenomenon.Aftergettingridofinterferences,thenetwork,intwoyearspractice,hasobservedseveralpre-seismicstrainanomaliesatstationsclosetoepicentersespeciallyintheWenchuanMS8.0megaquake.Itshowsthatthisboreholestrainmeternetworkiscapableofmonitoringseismogenicprocess.
简介:ThestudiesonthestructureandphysicalpropertiesoftheEarth'sinteriordonebyChinesegeophysicistsfrom1999to2002werereviewedinthispaper.Itincludesseveralresearchareas:thestructureoftheEarth'sinteriorsusingseismictomography,anisotropyoftheuppermantleinChinaanditsadjacentareas,qualityfactorQβforSwaves,subductionzone,mantlediscontinuities,physicalpropertiesofEarth'smaterialsandothers.Thereviewconcernsmainlythecontents,themethodsandtheresultsofthestudies.ItcanbeseenthatnewprogressinthestudyonthestructureandphysicalpropertiesoftheEarth'sinteriorhasbeenmadeinthelast4yearsinChina.Itisshownonthreeaspects:advancementmadeonsomepreexistentareas;pioneeringonsomenewfieldsandnewmethodsadopted.
简介:Completerecordsofmorethan3,000earthquakeeventsintheShanxi,WenzhoureservoirearthquakesequencewererecordedfromAugusttoNovember,2014bythehigh-density,high-resolutionmonitoringstationsoftheZhejiangRegionalDigitalSeismicNetworkandthereservoirearthquakemonitoringnetwork,withamaximummagnitudeofM4.2.Basedon3-Depicenterlocation,focalmechanismsolutions,andincombinationwiththegeologicalandtectoniccharacteristicsofthereservoirarea,theearthquakesequenceisdiscussedinthispaper.ThelinearfittingoftheHypoSATlocationresultsshowthatthemainshockoccurredintheNWtrendingfaultandtheearthquakesequenceisconcentratedinbandsalongtheactivefaults,withastrikeof305°,dippingSWwithdipangleof85°.ByusingP-wavefirstmotionsymbols,weobtainedtheaveragefocalmechanismofM≥3.5earthquakes,withastrike308°anddip84°fornodalplaneII.Thefieldgeologicalsurveyandresearchshowthatthestrike,dipandrakeofnodalplaneIIareroughlyconsistentwiththeoccurrenceoftheShuangxi-Jiaoxifault.ThecomprehensiveanalysisrevealsthattheNW-trendingShuangxi-Jiaoxifaultistheseismogenicstructureoftheearthquakes.
简介:ProcessofsourcedynamicsoftheJingtaiearthquake(M=6.2)Xue-BinDU(杜学彬);Zhi-DeYAN(闫志德)andMing-WuZOU(邹明武)(EarthquakeResearchInstitu...
简介:Therehavebeen12possiblelocationsoftheearthquakesoccurringintheSouthYellowSeasince1505.Inthispaper,thelocationoftheearthquakethatoccurredin1505hasbeendeterminedbythecollectionofmorehistoricaldataoftheinfluencedfield,referringtheisoseismaldataofearthquakeswiththeepicentralintensityⅨandcombininggeophysicalfielddatawithtectoniccondition,duetoitsgreatinfluenceonseismicsafetyassessmentofsomesignificantengineering.
简介:通过云南M≥7.6级地震震亡分布的统计,研究大地震的伤亡分布规律,寻找影响伤亡的主要原因。结果表明,震亡人数主要分布在Ⅷ度以上烈度区,这一区域的震亡人数占震亡总数的94%以上,其中极震区占到70%以上。调查分析认为:在震级相近的情况下,震区地质构造、地形地貌是影响地震烈度的因素;房屋、人口密度、发震时间是震亡人数的重要影响因素;在未来的大地震中,人口密度大的断裂带及其附近是应急救援和医疗救护的重点区域,在断裂带及其附近盆地内的震亡人数比非盆地震亡人数多,要投入更多的救援和医疗救护力量。
简介:Thispaperisthesecondinatwo-partseriesthatdiscussestheprincipalaxesofM-DOFstructuressubjectedtostaticanddynamicloads.Theprimarypurposeofthisseriesistounderstandthemagnitudeofthedynamicresponseofstructurestoenablebetterdesignofstructuresandresponsemodificationdevices/systems.Underidealizeddesignconditions,thestructuralresponsesareobtainedbyusingsingledirectioninputgroundmotionsinthedirectionoftheintendedresponsemodificationdevices/systems,andbyassumingthattheresponsesofthestructureisdecoupleableinthreemutuallyperpendiculardirections.Thisstandardpracticehasbeenappliedtobothnewandretrofittedstructuresusingvariousseismicprotectivesystems.Verylimitedinformationisavailableontheeffectsofneglectingtheimpactofdirectionalcouplings(crosseffectsofwhichtorsionisacomponent)ofthedynamicresponseofstructures.Inordertoquantifysucheffects,itisnecessarytoexaminetheprincipalaxesofstructuresunderbothstaticanddynamicloading.Inthistwo-partseries,thefirstpaperisconcernedwithstaticloading,whichprovidesdefinitionsandfundamentalformulations,withtheconclusionthatcrosseffectsofastaticallyloadedM-DOFstructureresultingfromthelackofprincipalaxesareofinsignificantmagnitude.However,underdynamicorearthquakeloading,arelativelysmallamountofenergytransferredacrossperpendiculardirectionsisaccumulated,whichmayresultinsignificantenlargementofthestructuralresponse.ThispaperdealswithaformulationtodefinetheprincipalaxesofM-DOFstructuresunderdynamicloadinganddevelopsquantitativemeasurestoidentifycrosseffectsresultingfromthenon-existenceofprincipalaxes.
简介:AnM8.1earthquakethatoccurredwestoftheKunlunMountainsPasshascausedmorethan20collapsebodiesorzones,whicharemainlydistributednearthesurfaceseismicrupturezone,westofHohSaiLake.Thecollapsesareoffourtypes,bedrock,soilmassandicemasscollapsesandavalanches.Thespatialdistributionandthecharacteristicsofdevelopmentofthecollapsesareanalyzedinthepaper.Comparisedwiththosecausedbyotherearthquakes,thecollapsesaresmallerinscale.Inadditiontothelithologicalcharacteristicsofthecrustalmedia,topographic,geomorphicandclimaticfactors,weakerseismicgroundmotionisanimportantcauseforformationofthesmaller-scalecollapses.Thelongsurfacerupturezoneandweakergroundmotionareimportantfeaturesoftheseismicrupture,whichmayberelatedtothestructureofthepreexistingfault.
简介:1861M6。0地震发生在Pulandian的东方是有M6的另一强烈地震。0除1975HaichengMT以外。在Liaodong半岛的3地震。通过重复调查,1861地震的震中在Gupao被定位,Pulandian的村庄东方。基于损坏调查和现代仪器的地震数据,这项活动和Jinzhou差错,Pulandian海湾差错和趋势NW的地震风险的精确地点的分析Pulandian差错被分析。并且由比较在Pulandian和Haicheng之间的深seismogenic环境,,它被发现那neogenic活跃差错,趋势NW差错,与Jinzhou差错结合了,有更高地震的风险。趋势NW差错是1861M6的seismogenic结构。0地震。并且作为在Liaodong半岛的一个主要差错,Jinzhou差错控制了这个区域的seismicity。Pulandian海湾差错是相对不活跃的,与弱seismicity,并且对地震无关。
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简介:Thispaperpresentsamodifiedhalf-sine-squaredloadmodelofthejumpingimpulsesforasingleperson.Themodelisbasedonadatabaseof22,921experimentallymeasuredsinglejumpingloadcyclesfrom100testsubjects.Threedimensionalmotioncapturetechnologyinconjunctionwithforceplateswasemployedintheexperimenttorecordjumpingloads.Thevariationrangeandprobabilitydistributionofthecontrollingparametersfortheloadmodelsuchastheimpactfactor,jumpingfrequencyandcontactratio,arediscussedusingtheexperimentaldata.Correlationrelationshipsbetweenthethreeparametersareinvestigated.Thecontactratioandjumpingfrequencyareidentifiedasindependentmodelparameters,andanempiricalfrequency-dependentfunctionisderivedfortheimpactfactor.Thefeasibilityoftheproposedloadmodelisestablishedbycomparingthesimulatedloadcurveswithmeasuredones,andbycomparingtheaccelerationresponsesofasingle-degree-of-freedomsystemtothesimulatedandmeasuredjumpingloads.Theresultsshowthatarealisticindividualjumpingloadcanbegeneratedbytheproposedmethod.Thiscanthenbeusedtoassessthedynamicresponseofassemblystructures.
简介:HistoricaldataregardingZhangHeng'sseismoscopeisnotsingularproof.Actually,thefourearliesthistoricaldocuments,i.e.,ContinuationofHistoriographyofHanDynasty,HistoriographyoftheLaterHan,BookoftheLaterHanandDingRecordallhaverelevantrecordsofitsstructure,size,principle,responsetoearthquakeandactualapplications.Thesefiveaspectsaresupportedbyarchaeologicalresearch,unearthedculturalrelics,historicalearthquakesandmodernseismologicalstudy.Thesehistoricalmaterialscontainagreatdealofspecificinformationaboutthisancientseismoscope.Inconclusion,theauthenticityandreliabilityofZhangHeng'sseismoscopeareverified.
简介:DetailedexaminationofhistoricaldataofearthquakesandfieldinvestigationsofloesslandslidecausedbytheearthquakeandtracingofactivefaultsinLanzhouareaindicatethattheYijitanputown,oneofsixtownsofJinchengcity,wasdevastatedbythe1125Lanzhouearthquake.ThecitlyisnowlocatedintheVinylonFactorysouthofHekou(RiverMouth)intheXigudistictofLanzhoucity.WedelerminedthatthesixoldtownsmentionedinhistoricalrecordslieinanareastretchingfromthesouthofXigudistricttoHekouinLanzhou.Thisisconsistentwiththedistibutionofloesslandslidescausedbytheearthquake,theextensionofHoloceneactivefaults,andthedistributionoftracesoftheseismicrupturezone.Acomprehensiveanalysisshowsthattheseismogenicstructureforthe1125LanzhouM7.0earthquakeshouldbetheXianshuigoufaultsegmentatthewesternterminationofthenorth-borderactivefaultzoneoftheMaxianshanMountainswhicharelocatedinsouthofLanzhoucitywiththedistanceofonly4km.
简介:Relationshipbetweenfaultsandgenerationofinlandshallowearthquakes:enlighten-mentoftheM=7.2southernHyogoprefec-tureearthquakeTO...
简介:Amoredetailedanddeep-goinganalysisoftectonicconditionsforthe1989BohaiSeaM7.4earthquakeareahasbeenmadebasedonthedataofoilgeologicalexplorationandresultsofseismologicalresearches.TheobtainedresultfillsthegapinseismotectoulcresearchofLargeBohaiSeaearthquakeareaofNorthChina.TheearthquakeareaislocatedintheeasternpartofCenozoicriftedbasinoftheBohaiGulf,alongtheintersectionzonebetweentheNNE-trendingYingkou-WeifangfaultzoneandtheNW-trendingBeijing-Penglaifaultzone.IntheearlyTertiaryfault-depressionstage,threesetsoffaults,theNNE-,NW-,andW-E-trendingfaults,weredevelopedintheuppercrustinthearea.Theyarelistricandplanarintheform,ofnormalfaultcharacterandmostlythemajorfaultsinfaulteddepressions.Inthefault-depressionstagesincelateTertiary,thepreexistingfaultshaveundergonemovementtodifferentextent.Meanwhile,anewNE-trendingHuanghekou(YellowRiverMouth)-Miaoxibeifaultzonewasdeveloped.ThefocalfaultingoftheM7.4earthquake,strikingtoN45°EanddippingtoSE,isnearlyvertical,withdextralstrike-slipnature,andburieddowntodepthof15~34km.TheseismogenicfaultforthelargeearthquakeisnottheYingweifault,butthenewlygeneratedHuanghekou-Miaoxibeifault.