巖石點荷載試驗研究.pdf

1、西南交通大學碩士學位論文巖石點荷載試驗研究姓名：董立山申請學位級別：碩士專業：工程力學指導教師：喻勇201105西南交通大學碩士研究生學位論文第1I頁AbstractWiththedevelopmentoftheinfrastructureconstructionthesignificanceofrockstrengthtestbecomesmoreandmoreimportantPointloadtestistherelatively

2、popularwaytomeasuretherockstrengthinfieldexperimentanditisbasedontheexperimentaldataanddimensionalprinciple，butitsphysicalmeaningisnotclear：Currentresearchmainlyfocusesontherelationshipbetweenpointloadindexanduniaxialcom

3、pressivestrengthignoringthetestanalysisTheanalysisofthepointloadtestisofveryimportantpracticalsignificanceThisarticletakerockspointloadtestforresearchobject，mainlyonthefollow：1Simplifythepointloadtestconditionwetakethefi

4、niteelementmethodtoestablishthelinearelasticmaterialmodel，whichunderuniformlypressure，SpecimensaledestroyedbecauseoftensionAlongtheloadingdirectioncompressivestressdecreasegraduallyfromloadingpoint，perpendiculartoloading

5、direction，stressshowsabellshapedistributionThemaximumtensilestressappearsatloadingpointbelowTensilestressisrelevanttotheloadradiusandPoisson’Sratio2BasedonHertzcontacttheorycombinedwithfiniteelementmethod，thestressdistri

6、butioninloadingdirectionalediscussedaccordingtothesizeandmagnitudeofloadingstressTakeanAnalysisofstressistributionchangesinloadingdirectionunderuniformlypressureandHertzpressure。3TakingtheThreeGorgesgraniteastheresearcho

7、bject，usingparticleflowsofhvarePFC2D，weestablishvirtualspecimenstoresearchpointloadspecimendamageWesuccessfullysimulatethewholeprocessofloadingdestructioninpointloadtest，anddrawthestressdistributioninfailureprocessAtlast

8、wegotanimportantfeatureofbrittlematerials：theinternalstressWaszerobeforespecimendestroyed，butspecimensstillowntheabilityofbearingexternalforcekeywords：Pointloadindex；Linearelasticmaterial；HertzContactTheory；ParticleFlowT