简介：题目：水下板桩叶片对移动河床的影响研究　　目的：比较板桩叶片和简单的平板叶片在控制河床沉积物再分配时的效率。　　方法：1.在不受当地侵蚀现象影响的接近障碍物和下游区域的直线水道中研究河床的形态；2.使用不同的实验装置测试简单几何形状的平板叶片和复杂形状的603K叶片的性能；3.在不同的叶片迎角和浸没参数下，测试与其面积接近的结构和在远场中的河床形态。　　结论：1.叶片的形状和迎角影响其对河床形态所产生的作用，尤其是对于较大的淹没参数而言；2.平板叶片和板桩叶片对下游河床的重塑作用相似；3.随着迎角的增加，平板叶片将造成更深的冲刷孔。这可能归因于与平板叶片相关的马蹄形涡流增加的侵蚀能力，而板桩叶片的不均匀表面可减轻该涡旋的侵蚀强度。

简介：Thevibrationproblemofapileofarbitrarysegmentswithvariablemodulusunderexcitingforceisestablished,inwhichtheinfluenceofthesoilunderpiletoeandthesurroundingsistakenintoaccount.WithLaplacetransforms,thetransmitfunctionsforvelocityanddisplacementofpilearederived.Furthermore,intermsoftheconvolutiontheoremandinversedLaplacetransform,ananalyticalsolutionforthetimedomainresponseofapilesubjectedtoasemi-sineimpulseisdeveloped,whichisthetheoreticalbasisofthesonicmethodinpileintegritytesting.Basedonthesolution,thevibrationpropertiesofpilewithsharporcontinuousmodulusarestudied.Thevalidityofthisapproachisverifiedthroughfidddynamictestsonsomeengineeringpiles.Itshowsthatthetheoreticalpredictionandtheresponseofthepileareingoodagreement.

简介：Thisworkpresentsanewanalyticalmethodtoanalyzetheinfluenceofreactionpilesonthetestpileresponseinastaticloadtest.Inourmethod,theinteractiveeffectbetweensoilandpileissimulatedusingindependentspringsandthesheardisplacementmethodisadoptedtoanalyzetheinfluenceofreactionpilesontestpileresponse.Moreover,theinfluenceoftheshelteringeffectbetweenreactionpilesandtestpileonthetestpileresponseistakenintoaccount.Twocasesareanalyzedtoverifytherationalityandefficiencyofthepresentmethod.Thismethodcanbeeasilyextendedtoanonlinearresponseofaninfluencedtestpileembeddedinamultilayeredsoil,andthevalidityisalsodemonstratedusingcentrifugemodeltestsandacomputerprogrampresentedintheliterature.Thepresentanalysesindicatethattheproposedmethodwillleadtoanunderestimationofthetestpilesettlementinastaticloadtestiftheinfluenceofthepresenceofreactionpilesonthetestpileresponseisneglected.

简介：Basedonthecommercialcomputationalsoftware,athree-dimensionalfiniteelementmodeltosimulatethethermo-mechanicalbehaviorsinanuclearfuelrodisestablished;Bytakingintoconsiderationirradiation-swellingofthepelletandtheirradiationdamageeffectsinthecladdingtogetherwiththecouplingeffectsbetweenthetemperaturefieldandthemechanicalfield,theusersubroutinestodefinethespecialmaterialperformanceandboundaryconditionshavebeendevelopedindependentlyandvalidated.Three-dimensionalnumericalsimulationofthethermo-mechanicalcouplingbehaviorsinanuclearfuelrodiscarriedout,andtheevolutionrulesoftheimportantthermalandmechanicalvariablesareobtainedandanalyzed.Theresearchresultsindicatethat:(1)thefuelpelletswillbeincontactwiththecladdingathighburnup,whichwillinduceastrongmechanicalinteractionbetweenthem;(2)theirradiationcreepeffectplaysanimportantroleinthemechanicalbehaviorevolutioninthenuclearfuelrod.

简介：Asaspecialgeologicalphenomenon,thecharacterofcollapsibleloessfoundationiscollapsiblewhenpenetratedbywater.Thischaracterleadstothesoillosingloadbearingcapacitylargelyandmayleadtofoundationfailure.Pileisapopularfoundationusedincollapsibleloess.Thesqueezedbranchandplatepileisanewtypeofpiledevelopedinrecentyearsandhasnotbeusedinaprojectbefore.Inthispaperthreesqueezedbranchandplatepilesaretestedincollapsibleloessafterimmersionprocessing.Theresultsmaybeusedforreferenceinsimilarconstructionproject,andtoprovidetheoreticalreferencesforde-signingofthesqueezedbranchandplatepilesinengineeringpractice.

简介：Theinfluenceofinitialstrainstateonthedynamicresponseofanendbearingpileembeddedinisotropicsaturatedsoilisinvestigatedthroughthelinearizedtheoryofsmallelasticperturbationsuperposedonlargelystressedbodies.Thegoverningequationsforsoil,basedonBiot’sporoelasticitytheory,arederivedinthecylindricalcoordinates,andthepileismodeledbyusingtheone-dimensionalelastictheory.Theanalyticalsolutionsofpileimpedance,frequencyresponseofbothtwistangleandtimehistoryofvelocityresponseareobtainedbyusingofseparationofvariablestechnique.Finally,aparametricstudyoftheinfluenceofinitialstrainsonthetorsionalimpedance,twistangle,andvelocityresponseatthetopofthepileiscarriedout.

简介：AnumberofdrybridgeshavebeenbuilttosubstitutefortheroadbedontheQinghai-TibetRailway,China.Theaimofthisstudywastoinvestigatetheexothermicprocessofcast-in-place(CIP)pilefoundationofadrybridgeanditsharmtothestabilityofnearbyfrozenground.Wepresent3Dheatconductionfunctionsofaconcretepileandoffrozengroundwithrelatedboundaries.Ouranalysisisbasedonthetheoryofheatconductionandtheexponentlawdescribingtheadiabatictemperaturerisecausedbyhydrationheat.ResultsundercontinuousandinitialconditionswerecombinedtoestablishafiniteelementmodelofaCIPpile-frozengroundsystemforadrybridgeunderactualfieldconditionsincoldregions.NumericalresultsindicatedthattheprocesscouldeffectivelysimulatetheexothermicprocessofCIPpilefoundation.ThermaldisturbancetofrozengroundunderalongdrybridgecausedbythecastingtemperatureandhydrationheatofCIPpileswassubstantialandlong-lasting.Thesimulatedthermalanalysisresultsagreedwithfieldmeasurementsandsomesignificantrulesrelatingtotheproblemwerededucedandconclusionsreached.