学科分类
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305 个结果
  • 简介:Becauseofitsexcellentseismicperformance,reinforcedsoilretainingwallsareincreasinglyusedincivilengineering.Althoughmanycountrieshavepublishedcorrespondingdesigncodes,thedifferencesbetweenthemarestillrelativelylarge.UsingtheFHWACodeandtheCodeforSeismicDesignofRailwayEngineering(CSDRE),stabilitycalculationsofreinforcedsoilretainingwallswerecarriedoutandthesimilaritiesanddifferencesbetweenthesetwodesigncodeswereanalyzed.Accordingtothecomparativeanalysis,thefollowingconclusionsaredrawn:theinertiaforce,theearthpressureandthetensileforceofreinforcementscalculatedfromtheCSDREarelessthanthosefromtheFHWACode,andthesafetyfactorcalculatedfromtheformerislarger.AlthoughtheM-Omethodisrecommendedtocalculatethedynamicearthpressure,theFHWACodesuggestsahigheractionpointascomparedtotheCSDRE.

  • 标签: SEISMIC performance Reinforced soil retaining WALL
  • 简介:ThecharacteristicsofseismicgroundmotionsinsouthernChinaaredifficulttodeterminestatisticallyduetoalackofstronggroundmotiondata.Inthisstudy,astochasticfinite-faultgroundmotionmodelwasadoptedtosimulatetheseismicgroundmotionsatbedrockforsouthernChina,basedonparametersderivedfromsmallandmediumearthquakesthathaveoccurredintheregion.Fromthese,theresponsespectrawasestimated.Asetofgroundmotionattenuationrelationshipswasthendevelopedbasedonsimulatedpeakgroundmotionsandresponsespectralparametersthroughregression,whichwouldbeapplicableforuseinengineeringpractice.Throughcomparisons,itwasdemonstratedthattheproposedgroundmotionrelationshipsaregenerallyconsistentwiththoseobtainedfromotherreportedgroundmotionattenuationmodelsforsouthernChina.

  • 标签: 地震动 统计 地震调查 随机数据 光谱法 中国南部
  • 简介:At19:33p.monSeptember27,2003,anearthquakewithM7.9occurredintheRussiaMongolia-ChinaboundaryRegion.ItwasstronglyfeltintheAltayregionofXinjiang.Thelossescausedbytheearthquakewas76millionyuan(RMB).Someinformationabouttheearthquakewasoutlined,includingbasicparameters,focalmechanism,evaluationofearthquakedisasterlossesandsoon.Thesatelliteremotesensinginformationworkedinitialanalysisfordeformationofgroundandfailurephenomenon.

  • 标签: 俄罗斯-蒙古-中国 边界地区 地震强度 震源机制 遥感观测 构造环境
  • 简介:ThenorthernLiulengshanpiedmontfaultislocatedalongthesouthernmarginoftheYangyuanbasinandrepresentsadip-slipnormalfault,generallyNEE-trendingandNNW-dipping.LandformsoffsetbythefaultarefairlydevelopedandwellpreservedintheDushanpuareaofYangyuanCounty,HebeiProvince.TwotrencheswereexcavatedinfrontofascarpofthenorthernLiulengshanpiedmontfaultatDushanpuandtwopaleoseismiceventswererevealedinthetrenches,fromwhichseveralsampleswerecollectedfordating.ThesamplesweredatedusingtheIRSLdatingtechnique.Thepreliminaryresultshowsthepossibleagesofthetwopaleoseismicevents.

  • 标签: Liulengshan Mountain FAULT PALEOEARTHQUAKE IRSL dating.
  • 简介:Studyofgeothermalfielddata,terrestrialheatflowvalues,andothergeophysicaldatafromtheXingtai-ShuluareaofHebeiProvincemadeusmoreunderstandingofthedistributionofgeothermalfieldsanddeepstructuresandtheirinterrelation.Thestudyillustratesthatthegeothermalfieldhasanapparentlateralinhomogeneityandisevidentlycorrelatedbythestructureofthecrustanduppermantleinthearea.Therelationofthegeothermalfielddistributiontothestructureindicatesthatincomparisonwiththedepressionzone,theupliftzonehasahigherheatflowvalueandalargergeothermalgradient.Theanalysisoftherelationbetweendistributionofearthquakeepicentersandgeothermalfieldandmathematicalsimulationofthermalstressintheareasuggeststhatthermalstressplaysanimportantroleintheprocessofearthquakegeneration.

  • 标签: THERMAL effect UPPER MANTLE Xintai-Shulu region.
  • 简介:MomenttensorsolutionswereretrievedfortheearthquakeswarmthatoccurredduringNovemberandDecember2010intheBoshanminingarea,ShandongProvince,China.Theresultsshowedthatthedouble-couplecomponentsinthesourcemechanismswerehigheratthebeginningoftheswarmandconsistedmainlyofshearfaultingcontrolledbytectonicstress.Thesubsequenteventshadsignificantnon-double-couplecomponents,indicatingtensilefaulting.Thedouble-couplecomponentspredominatelypresentedasnormalfaultingandthePaxeswereorientatedalmostvertically.Theslipvectorsoftheswarmeventswererelativelystable.Withreferencetothetectonicfeaturesneartheepicenter,weconcludedthattheswarmwasaresultofsubordinatefaultmotionrelatedtotheWangmuMountainfaultandthathigh-pressureporefluidsplayedacrucialroleintheactivityoftheearthquakeswarm.

  • 标签: 波形反演 地震群 山东省 矿区 异常 构造特征
  • 简介:Basedonthecasestudiesandstatisticalanalysisofearthquake-relatedionosphericdisturbancesmainlyfromDEMETERsatellite,ground-basedGPSandionosoundingdata,thispapersummarizesthestatisticalcharacteristicsofearthquake-relatedionosphericdisturbances,includingelectromagneticemissions,plasmaperturbationsandvariationofenergeticparticleflux.AccordingtothemainresultsdonebyChinesescientists,fusingwiththeexistedstudyfromglobalresearches,seismo-ionosphericdisturbancesusuallyoccurredafewdaysorhoursbeforeearthquakeoccurrence.Parallelingtothesecasestudies,lithosphere-atmosphere-ionosphere(LAI)couplingmechanismsarecheckedandoptimized.Athermo-electricmodelwasproposedtoexplaintheseismo-electromagneticeffectsbeforeearthquakes.Apropagationmodelwasputforwardtoexplaintheelectromagneticwavesintotheionosphere.Accordingtotherequirementofearthquakepredictionresearch,Chinaseismo-electromagneticsatellite,thefirstspace-basedplatformofChineseearthquakestereoscopicobservationsystem,isproposedandplannedtolaunchatabouttheendof2014.ItfocusesoncheckingtheLAImodelanddistinguishingearthquake-relatedionosphericdisturbance.ThepreliminarydesignforthesatellitewilladoptCAST-2000platformwitheightpayloadsonboard.Itisbelievedthatthesatellitewillworktogetherwiththegroundmonitoringnetworktoimprovethecapabilitytocaptureseismo-electromagneticinformation,whichisbeneficialforearthquakemonitoringandpredictionresearches.

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  • 简介:通过对西宁市区28个街道办事处的各类房屋建筑面积的调查了解,进行了对西宁市区的房屋建筑的静态震害预测,当西宁及周边地区发生破坏性地震、波及西宁市区时进行快速评(盲)估工作提供较为科学的定量的参考数据。

  • 标签: 房屋建筑 震害预测 西宁市 破坏性地震 经济损失 人员伤亡
  • 简介:信息技术的采用大大提高了震害预测的精度和震灾快速评估能力。城市震害预测工作在地理信息系统和计算机模拟技术支持下,能有效对震灾的发生及时获取各种基础数据进行综合分析,并对震害造成的损失和社会影响进行科学估算。利用数字城市为我们提供的数据共享平台和技术系统,帮助政府快速了解震情、灾情、提出对策。同时,依据震害预测研究成果,结合数字城市、数字福建可为政府及有关部门了解防灾薄弱环节,采取减灾措施,制定城市减轻灾害的长远规划,提高城市抗御地震灾害的能力

  • 标签: 数字福建 震害预测
  • 简介:ThispaperreportstheinternalstructuresoftheBeichuanfaultzoneofLongmenshanfaultsystemthatcausedthe2008Wenchuanearthquake,atanoutcropinHongkou,Sichuanprovince,China.PresentworkisapartofcomprehensiveprojectofInstituteofGeology,ChinaEarthquakeAdministration,tryingtounderstanddeformationprocessesinLongmenshanfaultzonesandeventuallytoreproduceWenchuanearthquakebymodelingbasedonmeasuredmechanicalandtransportproperties.Outcropstudiescouldbeintegratedwiththoseperformedonsamplesrecoveredfromfaultzonedrilling,duringtheWenchuanEarthquakeFaultScientificDrilling(WFSD)Project,tounderstandalong-faultanddepthvariationoffaultzoneproperties.Thehangingwallsideofthefaultzoneconsistsofweakly-foliated,clayeyfaultgougeofabout1minwidthandofseveralfaultbrecciazonesof30-40mintotalwidth.Wecouldnotfindanypseudotachyliteatthisoutcrop.DisplacementduringtheWenchuanearthquakeishighlylocalizedwithinthefaultgougelayeralongnarrowerslipping-zonesofabout10to20mminwidth.Thisisanimportantconstraintforanalyzingthermalpressurization,animportantdynamicweakeningmechanismoffaults.Overlappingpatternsofstriationsonslickensidesurfacesuggestthatseismicslipatagiventimeoccurredinevennarrowerzoneofafewtoseveralmillimeters,sothatlocalizationofdeformationmusthaveoccurredwithinaslippingzoneduringcoseismicfaultmotion.Faultbrecciazonesareboundedbythinblackgougelayerscontainingamorphouscarbon.Faultgougecontainsilliteandchloriteminerals,butnotsmectite.Clayeyfaultgougenexttocoseismicslippingzonealsocontainsamorphouscarbonandsmallamountsofgraphite.ThestructuralobservationsandmineralogicaldataobtainedfromoutcropexposuresofthefaultzoneoftheWenchuanearthquakecanbecomparedwiththoseobtainedfromtheWFSD-1andWFSD-2boreholes,whichhavebeendrilledveryclosetotheHongkououtcrop.Thepresenceofcarbonandgr

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  • 简介:Becauseseismicactivitywithinmid-continentsisusuallymuchlowerthanthatalongplateboundaryzones,evensmallearthquakescancausewidespreadconcerns,especiallywhentheseeventsoccurinthesourceregionsofpreviouslargeearthquakes.However,thesesmallearthquakesmaybejustaftershocksthatcontinuefordecadesorevenlonger.TherecentseismicityintheTangshanregioninNorthChinaislikelyaftershocksofthe1976GreatTangshanearthquake.ThecurrentearthquakesequenceintheNewMadridseismiczoneincentralUnitedStates,whichincludesaclusterofM*7.0eventsin1811–1812andanumberofsimilareventsinthepastmillennium,isbelievedtoresultfromrecentfaultreactivationthatreleasespre-storedstrainenergyinthecrust.Ifso,thisearthquakesequenceissimilartoaftershocksinthattheratesofenergyreleaseshoulddecaywithtimeandthesequenceofearthquakeswilleventuallyend.WeusesimplephysicalanalysisandnumericalsimulationstoshowthatthecurrentsequenceoflargeearthquakesintheNewMadridfaultzoneislikelyendingorhasended.Recognizingthatmid-continentalearthquakeshavelongaftershocksequencesandcomplexspatiotemporaloccurrencesarecriticaltoimprovehazardassessments.

  • 标签: 余震序列 中国北方 大陆地震 危险性评估 美国 新马德里地震带
  • 简介:OnApril25,2015,aM_S8.1earthquakeoccurredinNepal.IntheTibetareaofChina,thisearthquakecausedheavycasualtiesanddamagetohousing,roads,communications,otherlifelineengineering,waterconservancyandotherinfrastructure.Thispaperintroducesthebasicsituationoftheearthquake,andbasedontheinvestigationandassessmentofseismicintensity,thedamageofthedisasterareaisanalyzed,andbuildingtypesanddamagetothelifelinesystemsandvariousindustriesaregiven.Throughtheanalysisofthecharacteristicsoftheearthquakedisaster,thispaperpointsouttheexistingproblemsinseismicfortification,andfinallyputsforwardproposalsforthepreventionandcontrolofearthquakegeologicaldisasters,scientificplanningfortherestorationandreconstruction,strengtheningearthquakepreventionanddisasterreductionpropaganda,improvingtheawarenessofearthquakepreparednessintheagriculturalandpastoralareas,strengtheningtheguidanceandsupervisionofhousingconstructioninruralareastoreducethecasualtiesandlosses,andpromotingtheharmoniousdevelopmentofeconomyinTibet.

  • 标签: 8.1级地震 西藏地区 震害特征 尼泊尔 地震地质灾害 防震减灾宣传
  • 简介:根据国内外已发生水库诱发地震震例资料,结合金钟水库库区的具体情况,应用概率预测法、综合影响参数预测法、两级模糊评判法、古登堡——里克特公式外推预测法、历史地震最高震级预测法等方法对金钟水库可能诱发的最大震级进行预测研究。

  • 标签: 金钟水库 诱发地震 最大震级预测
  • 简介:Ontheconditionthatthevelocityratioofcompressivewavetoshearwaveisstableduringthepropagatingprocessofseismicwave,thispaperdevelopsanestimationmethodformediumqualityfactorbasedonsinglestation'straveltimedifferencebetweendirectSandPwavesandthefirstperiodsignalofdirectPwave.8774highSNRwavedataaltogetherrecordedby75stationsareanalyzed.Theresultsshowthat:(1)underthenormalregionalstressfield,thequalityfactorsQmSPinthestabletectonicareaarehigherthanthatintheactivetectonicareaaroundtheWeifang-JiashansectionanditssurroundingareaintheTanlufaultzone;(2)intheJuxian-Tanchengsectiontheseismicwaveattenuationisrelativelyquick,andthemediaisrelativelybroken,suggestingnotectonicstressaccumulation;(3)theXinyi-Sihongsectioniscurrentlylockingandinaccumulatingelasticstrainenergystage,whichhasthedeepenvironmentandconditionsofstrongearthquakegenerationsimilartothoseofthe1668M8.5Tanchengstrongearthquake.

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  • 简介:PreliminaryresultsonkinematicmodeloftectonicblocksderivedfromhighprecisionGPSobservationsinSouthwestChinaLIRENHUANG1)(黄立人)...

  • 标签: GPS observation SOUTHWEST China TECTONIC block
  • 简介:Buisomg126earthquakefocalmechanismsolutions(Ms≥4.7)duringtheperiodof1963-1998,moderntectonicstressfieldinNorthChinaisinvertedbymeansofthestepbystepconv-ergence.Theinversionresultsindicatethatthetectonicstressfieldintheresearchregionisclearlyvariationalinspaceandtime:(1)Themiddlingprincipalstressaxisó2isbasicallyver-tical.Themaximumandminimumprincipalstressaxesó1andó2arenearlyhorizontal,buttheazimuthsofó1andó3areinconsistentindifferentdistrictsandperiods.(2)BeforetheTangshanearthquakein1976,thethreeprincipalstressaxesareuniform.Theazimuthofmaximumprincipalstressaxisó1is68°(strikinginaNEE-SWWdirection).(3)AftertheTangshanearthquake,themaximumprincipalstressaxisó1andminimumprincipalstressaxisó3havevariationsindifferentdistricts.InthenorthernareaofNorthChinaandontheeasternsideoftheTancheng-Lujiangfaultzone,themaximumprincipalstressaxisó1isalsostrikinginaNEE-SWWdirection.Itsazimuthis68°.ItistheasmeasthatbeforetheTangshanearth-quake.InthesouthernareaofNorthChina,themaximumprincipalstressaxisó1isstrikinginaE-Wdirectionanditsazimuthis87°.

  • 标签: 中国北部 反演分析 构造应力场 时空分析 唐山地震 1976年
  • 简介:Crack-inducedanisotropyinthecrustfromshearwavesplittingobservedinTangshanregion,NorthChinaYuanGAO(高原)Si-HuaZHENG;(郑斯华)andYong...

  • 标签: CRACK ANISOTROPY Tangshan CROSS-CORRELATION function SHEAR
  • 简介:Onthebasisoflocatingbythegeochemicalprospecting,shallowseismicsounding,drilling,geologicalprofiling,andneogeochronologicaldating,wefirstfoundoutthedislocationamountalongtheLiaocheng-LankaoburiedfaultsincetheQuaternaryandtheageofitslatestactivityphaseanddeterminedthattheupperbreakpointbythefaultdislocationreaches20mbelowthesurface.ThelatestactivityphasewasintheearlyHoloceneandthefaultisashallow-buriedactivefault.Anaveragedislocationratealongthefaultis0.12mm/asincetheQuaternary.Thus,itisaburiedactivefaultwithintermediatetostrongmovementstrengthintheeasternChina.

  • 标签: 隐藏断层 活动性 地震 地质构造 华东平原