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【英文标准名称】:StandardTestMethodforInSituStressandModulusofDeformationUsingFlatjackMethod
【原文标准名称】:使用扁千斤顶法现场测定变形的应力和模数的标准试验方法
【标准号】:ASTMD4729-2008
【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】:creep;flatjackhydraulicpressure;insitustress;modulusofdeformation;Deformation--rock;Drilling(insoil/rock);Fieldtesting--rock;Flatjackmethod;Gages;Isotropicrockspecimens;Modulus--soil/rockapplications;Rockmaterials/properties/analy
【摘要】:TestsinOrthogonalDirections8212;Theflatjackmostaccuratelydeterminesthestressparalleltothelongaxisoftheadit,becausethisstressistheleastaffectedbythepresenceoftheopening.(Theothertangentialstressishighlyconcentrated.)Inaddition,iftheaditisinastressfieldwhereoneofthestressesissignificantlylargerthantheothers(3or4times),certainlocationsintheaditmaybeinverylowcompressiveoreventensilestress.Flatjacktestsintheselocationscangiveanomalousandmisleadingresults.Becauseofthesefactors,thetestaditshouldhaveatleasttwo,andpreferablythree,long(atleast4to5timesthediameter),straightsectionsatabout90x00B0;toeachother.Testingshouldbedistributedevenlyinallthreesectionstoprovideredundantdataand,ifresultsinonesectionareanomalous,toallowtheprogramtoproducesufficientusabledata.Note18212;Notwithstandingthestatementsonprecisionandbiascontainedinthistestmethod;theprecisionofthistestmethodisdependentonthecompetenceofthepersonnelperformingit,andthesuitabilityoftheequipmentandfacilitiesused.AgenciesthatmeetthecriteriaofPracticeD3740aregenerallyconsideredcapableofcompetentandobjectivetesting.UsersofthistestmethodarecautionedthatcompliancewithPracticeD3740doesnotinitselfassurereliabletesting.Reliabletestingdependsonmanyfactors;PracticeD3740providesameansofevaluatingsomeofthosefactors.1.1Theflatjacktestmeasuresstressatarocksurface.Themodulusofdeformationandthelong-termdeformationalproperties(creep)mayalsobeevaluated.1.2AllobservedandcalculatedvaluesshallconformtotheguidelinesforsignificantdigitsandroundingestablishedinPracticeD6026.1.2.1Themethodusedtospecifiyhowdataarecollected,calculated,orrecordedinthisstandardisnotdirectlyrelatedtotheaccuracytowhichthedatacanbeappliedindesignorotheruses,orboth.Howoneappliestheresultsobtainedusingthisstandardisbeyonditsscope.1.3Limitation8212;Theflatjacktestmeasurestheaveragestressnormaltothesurfaceofthetestchamber.Undisturbedstresslevelsmustbedeterminedbytheoreticalinterpretationsofthesedata.1.4AssumptionsandFactorsInfluencingtheData:1.4.1Thestressreliefisassumedtobeanelastic,reversibleprocess.Innonhomogeneousorhighlyfracturedmaterials,thismaynotbecompletelytrue.1.4.2Theequationsassumethattherockmassisisotropicandhomogeneous.Anisotropiceffectsmaybeestimatedbytestingindifferentorientations.1.4.3Theflatjackisassumedtobe100%efficient.Thedesignandsizerequirementsof7.1weredeterminedtosatisfythisrequirementtowithinafewpercent.1.4.4Thejackisassumedtobealignedwiththeprincipalstressesonthesurfaceoftheopening.Shearstressesarenotcanceledbyjackpressure.Orientatingthetestsinthreedirectionsineachplanetestedpreventsthemisalignmentfrombeingexcessiveforatleastoneofthetests.1.5Thevaluesstatedininch-poundunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesaremathematicalconversionstoSIunitsthatareprovidedforinformationonlyandarenotconsideredstandard.1.6Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwit......
【中国标准分类号】:P21
【国际标准分类号】:93_020
【页数】:6P.;A4
【正文语种】:英语