非連續(xù)屏障隔振的三維分析.pdf

1、同濟(jì)大學(xué)碩士學(xué)位論文非連續(xù)屏障隔振的三維分析姓名：梁濤申請(qǐng)學(xué)位級(jí)別：碩士專(zhuān)業(yè)：巖土工程指導(dǎo)教師：高廣運(yùn)2003.2.1ABSTRACTWiththeincreasingenlargementoftheprocessofconquermgthenature，man—madevibrationevokedbypowermachines，trafficandconstructionactivities，etchasanincreasingef

2、fectonprecisioninstnmaents，equipment，buildingsandthelivingenvironmentofhumanbeingsaswellThestudyofprotectivemethodsagainstman—madevibrationhasbecomeasignificanttopicconfrontedbymanyresearchersIntllisthesistheisolationofs

3、tructuresfrommanmadevibrationbypilesasdiscontinuousbarriersiSnumericallystudiedinathreedimensionalcontextbyanadvancedboundaryelementmethod(BEM)infrequencydomainandthecontentsareasfclllows：nlesemiinfinitespacefundamentals

4、olutionofsimplifieddynamicmodelofsoilbaseundervenicaIharmonicforceactingatthesurfaceofthesoilbaseiSdeducedTheboundaryintegraIformulationiSthencreatedaccordingtothetheoremofreciprocityandtheboundaryconditionatthesoilpilei

5、nterfacesandnumericalexamplesarethensolvedusingprogramTheverticalamplitudesoftestpointsinthescreeningzonebehindbarriersarecalculatedandcomparedagainstthatofwithoutbarriersTheeffectsofpilescharacters(suchasdiameterspacing

6、，sectionform，sectionarealengthandarrangement，etc)andloadcharacters(suchasfrequencyandlocation)onthescreeningefficiencyofpilebsaTiersarestudiedandrelatedconclusionsa他obtainedTheresultsofnumericalstudiesandpracticalfieldte

7、stingshowthatgoodscreeningefficiencyandlargescreeningzonemaybeachievedbyusingpilesasvibrationbarriersDifferenttypesofvibrationisolationmaybeusedinpracticalapplication，dependingonthegeologicalandgeographicalsituationthety

8、peofexcitationandconstructionconditionsTwoormorerowsofpilesmaybeusedifonerOWofpilescannotmeetthedesignrequirementsAsforthesophisticatedvibrationisolationprojectwithhiglldemands，comprehensivemeasuresshouldbeusedUsingpiles

9、asdiscontinuousbarriersinactivenearfieldvibrationisolationhasbetterscreeningefficiencythaninpassivefarfieldvibrationisolationinengineeringpracticeThisthesispresentsthatLn，theratioofdiameterofpiletonetdistancebetweenpiles

10、iSthedecisivefactorofscreeningemciencyⅢSmakesabreakthroughintraditionalwayofstudyingtheeffectofpilecharactersonscreeningefficiencyinwhichtheeffectsofdiameterandspacingonscreeningefficiencywerestudiedseparatelyAccordingto

11、thescreeningefficiencycriterionpresentedbyWoods，inwhichAR，theratioofscreeningemciencymustbesmallerthan025，goodscreeningemciencymaybeachievedifLnisgreaterthan05BesidesLILthesectionareaofpileiSanotherkeyfactoraffectingthes

12、creeningemciencyThevibrationisolationeffectincreaseswithincreasingsectionareaandthesectionformhaslittleeffectonscreeningefficiencyKeywords：manmadevibration；discontinuousbarriers；vibrationisolation；screeningefficiency；scr