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【英文标准名称】:StandardTestMethodforPerformingLaboratoryDirectShearStrengthTestsofRockSpecimensUnderConstantNormalForce
【原文标准名称】:在恒定的常规应力下进行岩石样品的实验室直接剪切强度试验的标准试验方法
【标准号】:ASTMD5607-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D18.12
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:asperity;directshearstrength;discontinuity;displacement;rock;roughness;slidingfriction;stress;sperity;Directsheartest;Discontinuities--rock;Displacement--rockenvironments;Intactrockstrength;Rockmaterials/properties/analysis;Roughnes
【摘要】:Determinationofshearstrengthofarockspecimenisanimportantaspectinthedesignofstructuressuchasrockslopes,damfoundations,tunnels,shafts,wasterepositories,cavernsforstorage,andotherpurposes.Pervasivediscontinuities(joints,beddingplanes,shearzones,faultzones,schistosity)inarockmass,andgenesis,crystallography,texture,fabric,andotherfactorscancausetherockmasstobehaveasananisotropicandheterogeneousdiscontinuum.Therefore,theprecisepredictionofrockmassbehaviorisdifficult.Fornonplanarjointsordiscontinuities,shearstrengthisderivedfromacombinationbasematerialfrictionandoverridingofasperities(dilatancy),shearingorbreakingoftheasperities,androtationsatorwedgingoftheasperities.Slidingonandshearingoftheasperitiescanoccursimultaneously.Whenthenormalforceisnotsufficienttorestraindilation,theshearmechanismconsistsoftheoverridingoftheasperities.Whenthenormalloadislargeenoughtocompletelyrestraindilation,theshearmechanismconsistsoftheshearingoffoftheasperities.Usingthistestmethodtodeterminetheshearstrengthofanintactspecimenmaygenerateoverturningmomentswhichcouldresultinaninclinedshearbreak.Shearstrengthisinfluencedbytheoverburdenornormalpressure;therefore,thelargertheoverburdenpressure,thelargertheshearstrength.Insomecases,itmaybedesirabletoconducttestsinsituratherthaninthelaboratorytodeterminetherepresentativeshearstrengthoftherockmass,particularlywhendesigniscontrolledbydiscontinuitiesfilledwithveryweakmaterial.Note38212;Thequalityoftheresultproducedbythisstandardisdependentonthecompetenceofthepersonnelperformingit,andthesuitabilityoftheequipmentandfacilitiesused.AgenciesthatmeetthecriteriaofPracticeD3740aregenerallyconsideredcapableofcompetentandobjectivetesting/sampling/inspectionandthelike.UsersofthisstandardarecautionedthatcompliancewithPracticeD3740doesnotinitselfassurereliableresults.Reliableresultsdependonmanyfactors,PracticeD3740providesameansofevaluatingsomeofthosefactors.1.1Thistestmethodestablishesrequirementsandlaboratoryproceduresforperformingdirectshearstrengthtestsonrockspecimens.Itincludesproceduresforbothintactrockstrengthandslidingfrictiontestswhichcanbeperformedonspecimensthatarehomogeneous,orhaveplanesofweakness,includingnaturalorartificialdiscontinuities.Examplesofanartificialdiscontinuityincludearock-concreteinterfaceoraliftlinefromaconcretepour.Discontinuitiesmaybeopen,partiallyorcompletelyhealedorfilled(thatis,clayfillingsandgouge).Onlyonediscontinuityperspecimencanbetested.Thetestisusuallyconductedintheundrainedstatewithanappliedconstantnormalload.However,aclean,opendiscontinuitymaybefreedraining,and,therefore,atestonaclean,opendiscontinuitycouldbeconsideredadrainedtest.Duringthetest,shearstrengthisdeterminedatvariousappliedstressesnormaltotheshearedplaneandatvarioussheardisplacements.Relationshipsderivedfromthetestdataincludeshearstrengthversusnormalstressandshearstressversussheardisplacement(shearstiffness).Note18212;Thetermx201C;normalforcex201D;isusedinthetitleinsteadofnormalstressbecauseoftheindefinableareaofcontactandtheminimalrelativedisplacementbetweenupperandlowerhalvesofthespecimenduringtesting.Theactualcontactareasduringtestingchange,buttheactualtotal......
【中国标准分类号】:P13
【国际标准分类号】:13_080_20
【页数】:8P.;A4
【正文语种】:英语