简介：Inthispaper,antiplaneresponseofanisoscelestriangularhilltoincidentSHwavesisstudiedbasedonthemethodofcomplexfunctionandbyusingmovingcoordinatesystem.Thestandingwavefunction,whichcansatisfythegoverningequationandboundarycondition,isprovided.Furthermore,numericalexamplesarepresented;theinfluencesofwavenumberandangleoftheincidentwavesandtheangleofthehill'speakongroundmotionarediscussed.

简介：Inthisstudy,thenull-fieldboundaryintegralequationmethod(BIEM)andtheimagemethodareusedtosolvetheSHwavescatteringproblemcontainingsemi-circularcanyonsandcirculartunnels.Tofullyutilizetheanalyticalpropertyofcirculargeometry,thepolarcoordinatesareusedtoexpandtheclosed-formfundamentalsolutiontothedegeneratekernel,andtheFourierseriesisalsointroducedtorepresenttheboundarydensity.Bycollocatingboundarypointstomatchboundaryconditionontheboundary,alinearalgebraicsystemisconstructed.Theunknowncoefficientsinthealgebraicsystemcanbeeasilydetermined.Inthisway,asemi-analyticalapproachisdeveloped.Followingtheexperienceofnear-trappedmodesinwaterwaveproblemsofthefullplane,thefocusingphenomenonandnear-trappedmodesfortheSHwaveproblemofthehalf-planearesolved,sincethetwoproblemsobeythesamemathematicalmodel.Inthisstudy,itisfoundthattheSHwaveproblemcontainingtwosemi-circularcanyonsandacirculartunnelhasthenear-trappedmodeandthefocusingphenomenonforaspecialincidentangleandwavenumber.Inthissituation,theamplificationfactorfortheamplitudeofdisplacementisover300.

简介：Inthispaper,ananalyticmethodisdevelopedtoaddresssteadySH-wavescatteringandperformdynamicanalysisofmultiplecircularcavitiesinhalfspace.ThescatteredwavefunctionusedforscatteringofSH-wavesbymultiplecircularcavities,whichautomaticallysatisfiesthestress-freeconditionatthehorizontalsurface,isconstructedbyapplyingthesymmetryoftheSH-wavescatteringandthemethodofmulti-polarcoordinatessystem.Applyingthisscatteredwavefunctionandmethodofmovingcoordinates,theoriginalproblemcanbetransformedtotheproblemofSH-wavescatteringbymultiplecircularcavitiesinthefullspace.Finally,thesolutionoftheproblemcanbereducedtoaseriesofalgebraicequationsandsolvednumericallybytruncatingtheinfinitealgebraicequationstothefiniteones.Numericalexamplesareprovidedforcasewithtwocavitiestoshowtheeffectofwavenumber,andthedistancesbetweenthecentersofthecavitiesandfromthecenterstothegroundsurfaceonthedynamicstressconcentrationaroundthecavityimpactedbyincidentsteadySH-wave.

简介：AnanalyticalsolutionforscatteringofincidentSHwavesbyacircular-archillwithaconcentriccirculartunnelwasderivedbyFourier-Besselseriesexpansionandauxiliaryfunctionstechnique.Thesolutionisreducedtosolvingasetofinfinitelinearalgebraicequationsfinally.Theaccuraciesofthenumericalresultsarecheckedbytheresidualerrorsofboundaryconditionswiththetruncationorderincreasing.Thenumericalresultsshowthattheexistenceanddimensionofthetunnelhavegreateffectonmotionofthegroundsurfacenearbyanddynamicstressconcentrationofthetunnel.

简介：Thispaperpresentsaclosed-formsolutionfordiffractionofplaneSHwavesbyasemi-circularcavityinhalf-spacebyusingwavefunctionexpansionmethod.Accuracyofthesolutionischeckedbythedisplacementresidualandstressresidualalongtheboundaries.Numericalresultsshowthattherearenotabledifferencesforresponseamplitudesbetweenasemi-circularcavityandawhole-circularcavityinahalf-space.

简介：由地志的特征散布飞机嘘波浪在一分层横着各向同性(TI)一半空间被使用一个间接边界元素方法(IBEM)调查。第一，反飞机分层的TI一半空间的动态僵硬矩阵被建立，免费的地被使用直接僵硬方法解决。然后，草地函数为在分层的TI一半空间对一根使倾向的线起作用的一致地分布式的负担被导出，散布的地与推出的草地函数被构造。最后，免费的地被加到散布的获得全球动态回答。方法被把结果与出版的各向同性的作比较验证。两个都，不变、短暂的动态回答被评估并且讨论。在频率领域的数字结果证明为TI媒介的表面运动能与为各向同性的案例的那些显著地不同，它强烈依赖于anisotropy性质，事件角度和事件频率。在时间领域的结果证明材料anisotropy在最大的持续时间和时间历史的最大的振幅上有重要效果。

简介：本文经过对宏观前兆信息的报送、管理等有关事项的考察和分析,确立了宏观前兆信息管理系统的具体实现功能。并阐述了系统的体系结构和功能模块的设计,实现宏观前兆信息的在线添加和系统的在线管理。经过授权的用户可以通过Web浏览器,以人机交互式的客户端程序,实现对宏观前兆信息的在线添加、管理、查询和统计等功能。

简介：Thispaperpresents2.5DscatteringofincidentplaneSHwavesbyacanyoninlayeredhalf-spacebytheindirectboundaryelementmethod(IBEM).Thefreefieldresponseiscarriedouttogivethedisplacementsandstressesonthelinewhichformsboundaryofthecanyon.ThefictitiousuniformmovingloadsareappliedtothesamelinetocalculatetheGreen'sfunctionsforthedisplacementsandstresses.Theamplitudesoftheloadsaredeterminedbytheboundaryconditions.Thedisplacementsduetothefreefieldandfromthefictitiousuniformmovingloadshavetobeaddedtoobtainthewholemotion.Thenumericalresultsarecarriedoutforthecasesofacanyoninhomogenousandinonelayeroverbedrock.Theresultsshowthatthe2.5Dwavescatteringproblemisessentiallydifferentfromthe2Dcase,andthereexistdistinctdifferencesbetweenthewaveamplificationbyacanyoninlayeredhalf-spaceandthatinhomogeneoushalf-space.Thereasonsforthedistinctdifferenceareexplored,andtheeffectsofthethicknessandstiffnessofthelayerontheamplificationarediscussed.

简介：Theproblemonthedynamicresponseofarigidembeddedfoundationinthepresenceofanundergroundrigidtunnelandsubjectedtoexcitationofincidentanti-planeSHwavesisanalyzed.Byusingtheexactanalyticalsolutionforthetwo-dimensionalSH-wavepropagationinandaroundboththesurfacerigidfoundationandsubsurfacerigidtunnel,thoseaspectsoftheresultinggroundmotionsthatareofspecialinterestandimportanceforseismicresistantdesigninearthquakeanalyseshavebeenexamined.Thecomputedamplitudesoftheresultingperiodicgroundmotionsdisplayaverycomplicatedwave-interferencebetweenthesurfacefoundationandundergroundtunnelthatleadtoobservedstandingwavepatterns,togetherwithabruptchangesinthewaveamplitudesandlargeamplificationoftheincidentmotions.

简介：二斜角肌的Antiplane反应由嘘波浪的三角形的山和一个半圆柱的峡谷用波浪功能扩大和复杂功能方法被学习。第一，分析模型被划分成三部分，和波浪领域的排水量答案在三个区域基于边界条件被构造。三个领域然后被结合在分享的边界满足连词条件。另外，与半圆柱的峡谷的零压力的条件结合了，为这个问题的一系列无限的代数学的方程被导出。最后，数字例子被提供，地面运动上的不同参数的影响被讨论。

简介：Wepresentaparallelhybridalgorithmbasedonpseudospectralmethod(PSM)andfinitedifferencemethod(FDM)fortwo-dimensional(2-D)globalSHwavefieldsimulation.Thewhole-EarthmodelistakenasacrosssectionofsphericalEarth,andcorrespondingwaveequationsaredefinedin2-Dcylindricalcoordinates.SpatialderivativesinthewaveequationsareapproximatedwithefficientandhighaccuracyPSMinthelateralandhigh-orderFDMintheradialdirectiononstaggeredgrids.Thisalgorithmallowsustodividethewhole-Earthintosub-domainsinradialdirectionandimplementefficientparallelcomputingonPCcluster,whileretainshighaccuracyandefficiencyofPSMinlateraldirection.Atransformationofmomenttensorbetween3-DsphericalEarthandour2-Dmodelwasproposedtogivecorrespondingmomenttensorcomponentsusedin2-Dmodeling.Comparisonofmodelingresultswiththoseobtainedbydirectsolutionmethodshowsverygoodaccuracyofouralgorithm.Wealsodemonstrateitsfeasibilitywithalateralheterogeneouswhole-Earthmodelwithlocalizedvelocityperturbation.

简介：Theearth’ssurfaceirregularitiescansubstantiallyaffectseismicwavesandinduceamplificationsofgroundmotions.Thisstudyinvestigateswhetherandhowthesourcecharacteristicsaffectthesiteamplificationeffects.Ananalyticalmodelofalinesourceofcylindricalwavesimpingingonanalluvialvalleyisproposedtolinkthesourceandsite.Theanalyticalsolutiontothisproblemprovesoneaspectofthestrongeffectofsourceonsiteamplification,i.e.,thewavecurvatureeffect.Itisfoundthatthesiteamplificationdependsonthesourcelocation,especiallyunderconditionsofasmallsource-to-sitedistance.Whetherthedisplacementisamplifiedorreducedandthesizeoftheamplificationorreductionmaybedeterminedbythelocationofthesource.Itissuggestedthattraditionalstudiesofsiteresponses,whichusuallyignorethesourceeffect,shouldbefurtherimprovedbycombiningthesourcewithsiteeffects.

简介：Thispaperstudiesthree-dimensionaldiffractionofobliquelyincidentplaneSHwavesbytwininfinitelylongcylindricalcavitiesinlayeredporoelastichalf-spaceusingindirectboundaryelementmethod.Theapproachisvalidatedbycomparisonwiththeliterature,andtheeffectsofcavityinterval,incidentfrequency,andboundarydrainageconditiononthediffractionarestudiedthroughnumericalexamples.Itisshownthat,theinteractionbetweentwocavitiesissignificantandsurfacedisplacementpeaksbecomelargewhentwocavitiesareclose,andthesurfacedisplacementmaybesignificantlyamplifiedbytwincavities,andtheinfluencerangewithlargeamplificationcanbeaswideas40timesofthecavityradius.Surfacedisplacementsindryporoelasticcaseandsaturatedporoelasticcaseswithdrainedandundrainedboundariesareevidentlydifferentundercertaincircumstances,andthedifferencesmaybemuchlargerthanthoseinthefree-fieldresponse.

简介：The2008Wenchuanearthquake,amajorintraplateearthquakewithMw7.9,occurredontheslowlydeformingLongmenshanfault.Tobetterunderstandthecausesofthisdevastatingearthquake,weneedknowledgeoftheregionalstressfieldandtheunderlyinggeodynamicprocesses.Here,wedeterminefocalmechanismsolutions(FMSs)ofthe2008Wenchuanearthquakesequence(WES)usingbothP-wavefirst-motionpolaritydataandSH/Pamplituderatio(AR)data.AsP-wavepolaritiesaremorereliableinformation,theyaregivenpriorityoverSH/PAR,thelatterofwhichareusedonlywhentheformerhaslooseconstraintontheFMSs.Wecollectdatafromthreecategories:(1)permanentstationsdeployedbytheChinaEarthquakeAdministration(CEA);(2)theWesternSichuanPassiveSeismicArray(WSPSA)deployedbyInstituteofGeology,CEA;(3)globalstationsfromIncorporatedResearchInstitutionsforSeismology.Finally,129eventswithmagnitudeoverMs4.0inthe2008WESareidentifiedtohavewell-constrainedFMSs.Amongthem,83arewellconstrainedbyP-wavepolaritiesonlyasshownbyCaietal.(EarthqSci24(1):115–125,2011),andtherestofwhicharenewlyconstrainedbyincorporatingSH/PAR.BasedonthespatialdistributionandFMSsoftheWES,wedrawfollowingconclusions:(1)theprinciplecompressionaldirectionsofmostFMSsoftheWESaresubhorizontal,generallyinagreementwiththeconclusiongivenbyCaietal.(2011)butwithafewmodificationsthatthecompressionaldirectionsareWNW–ESEaroundWenchuanandENE–WSWaroundQingchuan,respectively.ThesubhorizontalcompressionaldirectionalongtheLongmenshanfaultfromSWtoNEseemstohavealeftlateralrotation,whichagreeswellwithregionalstressfieldinvertedbyformerresearchers(e.g.,Xuetal.,ActaSeismolSin30(5),1987;ActaGeophysSin32(6),1989;Cuietal.,SeismolGeol27(2):234–242,2005);(2)theFMSsoftheeventsnotonlyreflectedtheregionalstressstateoftheLongmenshanregion,butalsowereobviouslycontrolledbythefaultstosomeextent,whichwaspointedou

简介：日益膨胀的信息数据和不断丰富的网络应用,不但需要单位局域网络支持越来越多的联网用户,而且更要支持更丰富的媒体应用,以满足电子数据交换和数字音像综合处理的要求,因此,构建一个高速局域网已刻不容缓,本文主要探讨在福建省地震局新建的防震减灾大楼中构建一个适合当前需求,且在将来可方便、平滑升级的综合布线系统,为地震监测预报及抗震救灾打下坚实的基础

简介：本文采用地震学方法,分析了台湾南投“9·21”地震。结果表明震前存在孕震空区和地震活动性参数异常变化

简介：Therehavebeen12possiblelocationsoftheearthquakesoccurringintheSouthYellowSeasince1505.Inthispaper,thelocationoftheearthquakethatoccurredin1505hasbeendeterminedbythecollectionofmorehistoricaldataoftheinfluencedfield,referringtheisoseismaldataofearthquakeswiththeepicentralintensityⅨandcombininggeophysicalfielddatawithtectoniccondition,duetoitsgreatinfluenceonseismicsafetyassessmentofsomesignificantengineering.

简介：ThedistributionoftheintensityoftheMojiangMS5.9earthquakeinYunnanProvinceisexpounded,andthedamagecharacteristicsofbuildingsandthedamageratioandseismicdamageindexofvariousbuildingstructuresineachintensityareaarecomparedwiththoseofTheChineseSeismicIntensityScale.Themainbasisandmethodofseismicintensityassessmentarediscussedinthispaper.Itisconcludedthat:①Theseismicintensityshouldbebasedontheearthquakedamageofthehousingstructure,whichtakesupahighratiointheseismicintensityassessment.Itisrecommendedthatseismicintensityisestimatedbycalculatingtheaverageseismicdamageindex.②ThehighestintensityoftheMojiangMS5.9earthquakeisVIIIdegrees,withthelongaxistrendinginthenorth-westdirection.TheareaaboveVIIdegreesis5,180km^2.③TheintensitydistributionoftheMojiangMS5.9earthquakemeetsthenationalstandardandthedistributionlawofseismicintensityinYunnan.

简介：本文阐述了漳州“109”地震谣传概况,总结了这次地震谣传的特点、发生原因及采取的措施。从这次地震谣传可以看出地震知识的宣传教育还需要大力加强,要加强《中华人民共和国防震减灾法》、《地震预报管理条例》等法律法规的宣传解释,加强如何识别地震谣传的宣传教育,增强群众对地震谣言的识别能力,特别需要向乡镇干部宣传,使他们能回答群众的询问,如果基层干部能在地震谣言出现时,就开始劝导解释、可能不至于发生这么大范围的地震谣传事件。

简介：1999年9月21日台湾省南投县发生了7.6级的强烈地震,当时正好我当班,在地动房摇的情况下,加上这次地震的特殊性,将S波分的较向后,使地震“三要素”中的震中位置有误差,现将这次主震的分析过程做一总结。