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25 个结果
  • 简介:Athree-dimensionalrigidbodyontheshapeofaparallelepipedismodelledinordertorockonasideoravertexofthebase,inordertoevaluatetheseismicresponseofrigidblockslyingonahorizontalsupport.Thecenterofmassofthebodyisconsideredaseccentricwithrespecttoitsgeometriccenter.Asseismicinput,threeItalianrecordedaccelerograms,withdifferentspectralcontent,areused.Thestudyismainlyconductedtohighlightthedifferencesbetweentheseismicresponseof2Dand3Dmodelsofrigidblocks,withtheaimtounderstandif,insomecases,theuseofthe3Dmodelofrigidblockisrequiredtoobtainsaferresults.Infact,theoutcomesshowthatinsomerangesofthegeometricalandmechanicalparametersthatcharacterizetheexcitationandthebody,atwo-dimensionalmodel,whichisnotabletoconsiderthe3Drockingonavertex,canprovideunsaferesults.Inparticular,itisfoundthattheoverturningprocessofthethree-dimensionalblockcanoccurunderexcitationswhicharelowerthanthosewhichoverturnacorrespondingtwo-dimensionalblock.

  • 标签: SEISMIC EXCITATION 3D RIGID BLOCK rectangular
  • 简介:StudyoncorrelativityamongcapacitydimensionD0,infor-mationdimensionD1,algorithmiccomplexityC()andbValueWEI-BINHAN(韩渭宾),GUI-X...

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  • 简介:Theconventionalpseudo-staticapproachoftenneglectstheeffectoftheverticalseismicaccelerationonthestabilityofaslope,butsomeanalysesunderplane-strain(2D)conditionsshowasignificanteffectontheslopestability.Thepurposeofthisstudyistoinvestigatetheeffectoftheverticalaccelerationonthesafetyofthree-dimensional(3D)slopes.Inthestrictframeworkoflimitanalysis,a3Dkinematicallyadmissiblerotationalfailuremechanismisadoptedherefor3Dhomogeneousslopesinfrictional/cohesivesoils.Asetofstabilitychartsispresentedinawiderangeofparametersfor3Dslopesundercombinedhorizontalandverticalseismicloadingconditions.Accountingfortheeffectsoftheverticalseismicacceleration,thedifferenceinsafetyfactorsfor3Dslopescanexceed10%,whichwillsignificantlyoverestimatethesafetyofthe3Dslopes.

  • 标签: 边坡稳定性 三维运动学 地震加速度 垂直加速度 拟静力法 平面应变
  • 简介:华南内陆地区地震活动以中强地震为主,第四纪以来活动断裂不发育,因此,对发震构造条件的认识存在较大不确定性。本文着[于中生代以来构造]化进程对形成本地区地质构造背景和地震活动特征的重要意义,统计分析了该地区地震活动分布与K-N地层的关系。结果表明,两者之间具有非常显著的相关性,可以将K-N地层分布区作为该地区发震构造鉴定和潜在震源区划分的重要条件之一,并初步认为华南地区特殊的地质构造演化历史是该地区K-N地层分布区地震活动性较强的主要原因。

  • 标签: 中强地震 小震密集区 发震构造 K-N地层
  • 简介:AmodelofseismicitywithfractalstructuresandapreliminarydiscussionontherelatiobetweenDandbvalueHat-KunJIANG(蒋海昆)andShou-ZhongDI...

  • 标签: 守中
  • 简介:Preliminaryresultof3DgravitationalforwardcalculationstudyinBohaiSeaGUANGXIALIU1)(刘光夏)WENJUNZHAO2)(赵文俊)WENJUREN1)(任文菊)XIU...

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  • 简介:Theexperimentalresultsof3-Dfractureundercompressionareintroducedinbriefandthetheoryofstresscriterionof3-Dfractureisstudied.Methodstoimitateinitialfracturesaredeveloped.Itispointedthatthereareimportantdefectsintheextremevalue(EV)methodeverproposedbyPalaniswamyandKnauss.ThemajordefectliesinthatonlytwoEulerangles(2EA)areconsidered,butanotheroneisneglected.IfthevariationofallthethreeEulerangles(3EA)areconsidered,onecangetbetterresultwhichisconsistentwiththeobservationoffaultingthatextendsoncurvedsurfacesbutnotonplanes.Themethodofevaluatingmaximalnormalstressdirectionvector(NSDV)isproposedandfurtherprovedtobeequivalenttothe3EAmethod.ItisprovedthattheNSDVmethodcanbefurtheroptimizedtothemethodofcompositionofthefirstprincipaldifferentialplane(CFPDP).TheresultsfromCFPDPmethodcanfitthecurvedsurfacesofinitialgrowthobservedintheexperimentsof3-Dfracture.TheCFPDPmethodcanalsobeusedtointerpretthe3-Dfracturesoftheslippingsectionbetweentheasperitiesintheburiedfaultplanethatismodeledasellipsecrack.Theresultsof3-Dfracturecanbeappliedtointerpretingtherelatedproblemsoffaultingincludingthemechanismofalotofshatterrockswithdifferentdimensions,thecauseofearthquakesoccurredattheedgeofplateunderlowshearstress,andthemechanismofanisotropycausedbytheextensivedilatancyanisotropy(EDA)cracks.

  • 标签: 隐伏断层 骨折 实验 各向异性 评估方法 方向向量
  • 简介:Thispaperpresents2.5DscatteringofincidentplaneSHwavesbyacanyoninlayeredhalf-spacebytheindirectboundaryelementmethod(IBEM).Thefreefieldresponseiscarriedouttogivethedisplacementsandstressesonthelinewhichformsboundaryofthecanyon.ThefictitiousuniformmovingloadsareappliedtothesamelinetocalculatetheGreen'sfunctionsforthedisplacementsandstresses.Theamplitudesoftheloadsaredeterminedbytheboundaryconditions.Thedisplacementsduetothefreefieldandfromthefictitiousuniformmovingloadshavetobeaddedtoobtainthewholemotion.Thenumericalresultsarecarriedoutforthecasesofacanyoninhomogenousandinonelayeroverbedrock.Theresultsshowthatthe2.5Dwavescatteringproblemisessentiallydifferentfromthe2Dcase,andthereexistdistinctdifferencesbetweenthewaveamplificationbyacanyoninlayeredhalf-spaceandthatinhomogeneoushalf-space.Thereasonsforthedistinctdifferenceareexplored,andtheeffectsofthethicknessandstiffnessofthelayerontheamplificationarediscussed.

  • 标签: 层状半空间 平面SH波 散射问题 峡谷 入射 间接边界元法
  • 简介:边界条件能显著地在强烈地震下面影响斜坡行为。为了为有限元素(FE)评估边界条件的重要性,一张饮料桌子的模拟在斜坡反应上试验,一验证三维(3D)非线性的FE模型被介绍,并且数字、试验性的结果被比较。为那个目的,基于公开源码的计算站台OpenSees,柔韧的图形的用户接口SlopeSAR被采用,它简化努力集中的预处理和processing以后阶段。网孔决定效果也被探讨。参量的研究被执行在在结束脸包含边界程度和边界条件的三种类型的FE模型上评估边界条件的影响。通常,在边界程度的变化生产不一致的斜坡变丑。为二张结束脸,修理y方向排水量不是适当的模仿饮料桌子实验,结束墙在僵硬、不平。另外,3D的长度的影响倾斜最高的脸和处于二之间的差别的一个重要角色在结束边界条件打的斜坡戏的宽度面对(修理y方向排水量并且修理(y,z)方向排水量)。总的来说,这研究加亮对在模拟和试验性的结果之间的比较的评价竟然与到期的考虑被执行到边界的效果,这调节。

  • 标签: 边界条件 条件模拟 边坡变形 地震反应试验 三维 有限元模型
  • 简介:2.5D有限/无限的元素途径被采用学习秘密地移动火车引起的波浪繁殖问题。包括隧道结构和土壤的部分,近的地的不规则被有限元素,和延长到无穷的远地的波浪繁殖性质建模被无限的元素建模。2.5D途径的一个特别特征是它启用一半空间的三维的反应的计算,考虑负担动人效果,用仅仅二维的侧面。尽管有限/无限的元素途径给在学习波浪繁殖的优点由移动引起了的一个伟人看的2.5D训练,注意应该被给计算方面,例如网孔建立的规则,以便避免生产不精密或错误的结果。在这份报纸,某必需品指因为在分析的考虑被加亮,与提高计算的速度的技术一起。这些观察应该在使2.5D成为有限/无限的元素证明有用的所有接近有效的。关键词扎根了颤动-2.5D有限/无限的元素-地下的火车-波浪数字-旁边支持的波浪繁殖:科学委员会在下面资助没有。NSC89-2211-E-002-020

  • 标签: 无限元法 地铁列车 地表震动 计算速度 有限元素 无限元方法
  • 简介:Inthispaper,wedeterminedanearthquakesequencelocationintheXingfengjiangareafromJune,2007toJuly,2014andthe3DP-wavevelocitystructurebyasimultaneousinversionmethod.Onthatbasis,westudiedtheoccurrencefeaturesofactivetectonicsandtheearthquakesourcemechanism.Theresultsshowthatthereservoirfracturesystemhasatendencytoincreasewithgradualdepthfromsoutheasttonorthwest,consistentwithgravitationalfieldresearchresults.Thereare4highvelocityzones(HVZ)underthedepthofthe7km-12kmcrustbetweentheXinfengjiangReservoirdamandXichangDistrict,Dongyuan.ThemaxvelocityofthebiggestHVZwhichisunderXichangis6.3km/s.Underthereservoirdamthereisastrongtectonicdeformationzone,asthecenterexitRenzishifault(F2),Nanshan-Aotoufaults(F4),Heyuanfault(F1)andShijiao-Xingang-Baitianfault(F5),7earthquakeswithML≥5.0(includingM6.1inMarch,1962)occurredatthehighgradientzoneoftheHVZⅢandHVZⅣedgewhichhasbeenunderthereservoirdamsince1960,withrelativityenergyreleasingmorethoroughly.ModerateseismicactivityoccurredattheHVZⅠedgewhichhasbeenunderXichangsince2012,andisadangerzoneforM5.0earthquakesinthefuture.

  • 标签: P-WAVE velocity STRUCTURE Active TECTONICS SIMULTANEOUS
  • 简介:一个方法被建议在设计实践为使用估计地震soil-structure-interaction(SSI)效果。它对受到的2D结构适用垂直地事件砍波浪由同质的一半空间支持了。自从它保留简洁,方法是吸引人的光谱途径,克服一些困难和存在古典技术的不确,然而,它考虑身体上一致的刺激。简洁的这水平通过回答被完成能被用于免费地的5%阻尼反应系列产出设计的系列修正因素光谱考虑散布运动的纵标由相互作用效果介绍了。修正因素在结构的相对排水量和免费地的运动之间的转移功能(TF)是代表性的,它以它的最大的振幅被描述并且联系了频率。由练习工程师计算修正因素的表情被建议用实际结构的576盒子代表在参量的研究之上基于。方法在跨越大量普通基本颤动时期的10种情况中被测试。

  • 标签: 土-结构相互作用 二维模型 地震 程序 修正系数 工程实践
  • 简介:3DstructuralreconstructionofMohointheTangshanearthquakeareabyusinginversionofcurvedinterfaceXIAOLINGLAI(赖晓玲)XIANKANGZHANG...

  • 标签: sectional INCOMPLETE POLYNOMIAL INTERFACE 3 D
  • 简介:Inthispaper,weproposeanearlyanalyticexponentialtimedifference(NETD)methodforsolvingthe2Dacousticandelasticwaveequations.Inthismethod,weusethenearlyanalyticdiscreteoperatortoapproximatethehigh-orderspatialdifferentialoperatorsandtransformtheseismicwaveequationsintosemi-discreteordinarydifferentialequations(ODEs).Then,theconvertedODEsystemissolvedbytheexponentialtimedifference(ETD)method.WeinvestigatethepropertiesofNETDindetail,includingthestabilityconditionfor1-Dand2-Dcases,thetheoreticalandrelativeerrors,thenumericaldispersionrelationforthe2-Dacousticcase,andthecomputationalefficiency.Inordertofurthervalidatethemethod,weapplyittosimulatingacoustic/elasticwavepropagationinmultilayermodelswhichhavestrongcontrastsandcomplexheterogeneousmedia,e.g.,theSEGmodelandtheMarmousimodel.Fromourtheoreticalanalysesandnumericalresults,theNETDcansuppressnumericaldispersioneffectivelybyusingthedisplacementandgradienttoapproximatethehigh-orderspatialderivatives.Inaddition,becauseNETDisbasedonthestructureoftheLiegroupmethodwhichpreservesthequantitativepropertiesofdifferentialequations,itcanachievemoreaccurateresultsthantheclassicalmethods.

  • 标签: 地震波方程 时间 二维 求解 差分法 常微分方程
  • 简介:BasedonthefirstarrivalPandSdataof4625regionalearthquakesrecordedat174stationsdispersedintheYunnanandSichuanProvinces,the3-Dvelocitystructureofcrustanduppermantleintheregionisdetermined,incorporatingwithpreviousdeepgeophysicaldata.Intheuppercrust,apositiveanomalyvelocityzoneexistsintheSichuanbasin,whereasanegativeanomalyvelocityzoneexistsinthewesternSichuanplateau.TheboundarybetweenthepositiveandnegativeanomalyzonesistheLongmenshanfaultzone.TheimagesoflowercrustanduppermantleintheLongmenshanfault,Xianshuihefault,Honghefaultandothersshowthecharacteristicoftectonicboundary,indicatingthatthefaultslikelypenetratetheMohodiscontinuity.Thenegativevelocityanomaliesatthedepthof50kmintheTengchongvolcanicareaandthePanxitectoniczoneappeartobeassociatedwiththetemperatureandcompositionvariationsintheuppermantle.TheoverallfeaturesofthecrustalandtheuppermantlestructuresintheSichuan-Yunnanregionaretheloweraveragevelocityinbothcrustanduppermostmantle,thelargecrustalthicknessvariations,andtheexistenceofhighconductivitylayerinthecrustor/anduppermantle,andhighergeothermalvalue.AllthesefeaturesarecloselyrelatedtothecollisionbetweentheIndiaandtheAsiaplates.ThecrustalvelocityintheSichuan-Yunnanrhombicblockgenerallyshowsnormalvalueorpositiveanomaly,whilethenegativeanomalyexistsintheareaalongthelargestrike-slipfaultsastheblockboundary.Itisconducivetothecrustalblockside-pressingoutalongthefaults.Inthemajorseismiczones,theseismicityisrelativetothenegativeanomalyvelocity.Moststrongearthquakesoccurredintheupper-midcrustwithpositiveanomalyornormalvelocity,wherethenegativeanomalyzonegenerallyexistsbelow.

  • 标签: REGIONAL earthquake MOHO DISCONTINUITY 3-D velocity
  • 简介:以伊朗巴姆地区为例,对伊朗巴姆地震造成的地表形变进行了差分干涉测量,得到了垂直向的同震三维形变场,并运用GIS三维分析技术对形变场进行了分析。实验结果表明,地震在巴姆城市的东侧造成了较大形变,在西侧也产生了微量形变。巴姆城市北部地块沉降,南部地块隆起。同时在巴姆城市南部可明显看到地震造成的断层。实验结果验证了基于C波段的SAR数据的D-InSAR技术在干燥地区监测地表形变方面的可行性。本文对产生去相关效应的原因进行了解释,认为对于干燥少植被的地区干涉效果较好。并指出,如果能够通过技术进步提高雷达干涉测量的精度并降低观测成本,同时将该技术与GPS、GIS等技术相结合,从而更好地研究形变机理,这将对地质灾害的研究产生重大意义。

  • 标签: 差分合成孔径雷达干涉测量(D-InSAR) 同震形变场 去相关效应 ENVISATASAR数据 伊朗巴姆地震
  • 简介:Theinversionof3┐DcrustalstructureandhypocenterlocationintheBeijing┐Tianjin┐Tangshan┐Zhangjiakouareabygeneticalgo┐rithmYONG-G...

  • 标签: GENETIC ALGORITHM HYPOCENTER CRUSTAL STRUCTURE INVERSION