简介:Inthispaper,anewhybridcontroltechnique,basedonacombinationofbase-isolationandsemi-activevariablestiffness/dampinginasuperstructure,ispresented.Toillustratetheefficiencyoftheproposedcontrolsystem,modeltestsonamini-electromagneticshakingtableandanumericalsimulationwereperformed.Thetestandnumericalcalculationresultsindicatethatthisnewhybridcontrolmodewithadditionaldampingandsmalleradditionalstiffnesscanachieveabettercontrolefficiency.
简介:Liquefactiontestingatasaturatedloesssitewasperformedunderthesimulatedearthquakegroundmotioninducedbyartificialexplosionswithmicro-timeintervals.Thetimehistoriesofgroundacceleration,porewaterpressureandtheultimatevalueofresidualstrainwererecordedandmeasured.ThemodifiedFEQdraincomputationsoftwarewasusedtoanalyzetheliquefaction.Boththetestandtheanalysisconfumtheobjectiveoccurrenceofloessliquefaction.Furthermore,thereliabilityofthemethodoftheloessliquefactionanalysisbasedonFEQdrainandthemodelofporewaterpressuredevelopmentofsaturatedloessareexamined.
简介:这份报纸论述是可扩展的因为地理上散布了的联机混合测试系统测试的一个基础。这个系统由通常过去常让周期的测试装载测试基础到目标排水量或目标力量上的一套设备组成。由于他们的坚韧性和可移植性,常规装载设备的单个集合能被搬运并且重新设置认识到在地理上遥远的实验室的物理装载。另一个呼吁的特征是对在各种各样的性能期间在僵硬有大不同的标本特别地合适的混合控制上演的灵活排水量力量。进行一个基础联机混合测试,一个可扩展的框架被开发,它与一个概括接口被装备包含每个基础。用各种各样的结构的程序代码的多重测试基础和分析基础能在单个框架以内被提供,简单地与边界排水量和力量连接了。一个协调人程序被开发在所有基础兼容机和equilibrated之中保留边界。一个基于因特网的数据交换计划也被设计在与不同软件环境装备的计算机之中转移数据。一系列联机混合测试被介绍,并且联机混合测试系统的可移植性,灵活性,和可扩展性被表明。
简介:Withthefastdevelopmentofbridgeconstructioninmountainousandseismicareas,itisnecessarytoconductrelatedresearch.Basedonthedesignofashakingtablemodeltest,herearethefollowingtestresults:thefilteringeffectexistsinsoilandisaffectedbythedynamicconstraintconditions,theamplitudeisstrengthenedaroundthenaturalfrequencyandweakenedinotherfrequencybandsintheFourierspectrum.Sincetheaccelerationscalingeffectoccurredonaslopedsurface,theaccelerationresponsedecreasesfromtheoutsidetotheinsideinsoil.Thedynamicresponseisrelativelystrongneartheslipsurfaceinbedrockduetothereflectionofseismicwaves.Thefailuremodeoflandslideisdecidedbytheslopeangleandslippingmassdistribution,andthetestshowsthefrontrowstabilizingpilesshouldkeepaproperdistancefrombridgefoundationsothatseismicresistancecanbeguaranteedforthebridgefoundation.
简介:Cement-mixedpiles,ascountermeasureagainstliquefactionofsiltandsandground,canimprovetheshearstrengthandbearingcapacityoffoundationsoil,meaningcement-mixedpilesarecapableofresistingdisplacementwhenanearthquakehappens.However,investigationsofcement-mixedpilesbyexperimentalmethodssuchastheshakingtabletestisfewandfarbetween.Itisespeciallytruefortheseismicperformanceofcement-mixedpilesinliquefiablerailwayfoundationsinhighseismicintensityregions.Tothisend,across-sectionoftheYuxi-Mengzirailwaywasselectedastheprototypeandstudiedbytheshakingtabletestinthisstudy.Theresultsshowedthatcompositefoundationofcementmixedpileswasnotliquefiedwhentheseismicaccelerationwaslowerthan0.30g.Intheprocessofaccelerationincreasingfrom0.30gat2Hzto0.60gat3Hz,theuppermiddlesiltoutsideslopetoewaspartlyliquefied.Thefoundationsoilundertheshouldersandcenterofsubgradewasfarfromtheinitialliquefactioncriterionduringthetest.Cementmixedpilescaneffectivelyreducetheembankmentsettlementanddifferentialsettlement.Itcanbeconcludedthat,thedesignofcement-mixedpilescanensuretheseismicperformanceofthesubgrade,andsatisfytheseismicdesignrequirementsoftheYuxi-MengzirailwayinareasofVIIIdegreesseismicfortificationintensity.
简介:称为走的墙框架结构的一个新结构的系统在这研究被建议解决产出RC框架的问题的底部,它广泛地在中国发生在象Wenchuan和Yushu地震那样的以前的地震期间。平常的RC框架模型和一个走的墙框架建模的A1/5规模被使遭到一起摇桌子运动学习新结构的系统的地震行为。这份报纸在低、中等、高的紧张摇晃下面论述动态特征,地震回答和失败和二个模型的倒塌机制。测试结果和进一步的分析证明走的墙框架结构的地震表演以控制得好的变丑模式和更一致地分布式的损坏比平常的RC框架优异。走的墙能有效地压制产出机制的底部,并且为设计实践简单、节俭、实际。
简介:Adynamicmodeltest(CL=4)atdifferentvelocitiesoftrain,namelydifferentloadingfrequencies,iscarriedouttostudythedynamiccharacteristicsofahigh-speedrailwaytunnelinvertanditsfoundationsoils.Notonlyaretheaccelerations,dynamiccoefficients,dynamicstressesoftheinvertandfoundationsoilsemphaticallyanalyzed,theirrelationshipwiththevelocityofthetrainarediscussedindetail.Throughlaboratorytesting,theattenuationofvibrationpropagatingfromuptherailsisobtainedandthecalculationformulaofthespeedinfluencecoefficientofthetunnelinvertispreliminarilyestablished.Thedepthofthefoundationsoilsinfluencedbyvibrationisalsodeterminedinthisstudy.Itisshownthattheresponsesofthetunnelinvertandfoundationsoilstovibrationareslightlyincreasedwiththevelocityofthetrain;circumferentialstressesinthebottomoftheinvertaretensilestressesandmaximumstressesappearunderthefootoftherails;thedynamicsoilpressuresofthefoundationdecreasequicklywiththedistanceawayfromthetunnelinvertandanexponentialrelationshipexistsbetweenthem.
简介:WecompilearegionalcatalogueofearthquakeswithmomentmagnitudeoftheCenter-SouthernAsiatestarea(20°-35°N,85°-105°E)fortheGlobalSeismicHazardAssessmentProgram(GSHAP).Therearesignificantinhomogeneousanduncompleteddata,andnuniformityofearthquakemagnitudesinthistestareabecausethisregionissituatedontheboundariesofmanycountries,suchasChina,India,Nepal,Vietnam,etc.WeestablisharelationshipbetweenGutenbergsurface-wavemagnitudeandIASPEIsurface-wavemagnitude,whichcanbeusedforconversionofdifferentmagnitudescalesintomomentmagnitudeforthiscatalogue.AcatalogueofeventswithMw≥6.0ofthistestareaisgivenattheendofthispaper.
简介:Artificialearthquakecataloguesimulationisoneofthewaystoeffectivelyimprovetheincompletenessoftheexistingearthquakecatalogue,thescarcityoflargeearthquakerecordsandtheimprovementofseismologicalresearch.BasedonthePoissondistributionmodelofseismicactivityandtheGutenberg-Richtermagnitude-frequencyrelationship,theMonteCarlomethodwhichcandescribethecharacteristicsofthestochasticnatureandthephysicalexperimentprocessisused.ThispapersimulatesthefutureseismiccataloguesoftheFenhe-Weiheseismicbeltofdifferentdurationsandconductsstatisticaltestsonthem.TheanalysisshowsthatthesimulationcataloguemeetsthesetseismicactivityparametersandmeetsthePoissondistributionhypothesis,whichcanobtainabettersimulatedearthquakecataloguesthatmeetstheseismicactivitycharacteristics.Accordingtothesimulatedearthquakecatalogues,futureearthquaketrendsinthisregionareanalyzedtoprovidereferenceforseismichazardanalysis.