Designation:D7181−20StandardTestMethodforConsolidatedDrainedTriaxialCompressionTestforSoils1ThisstandardisissuedunderthefixeddesignationD7181;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthedeterminationofstrengthandstress-strainrelationshipsofacylindricalspecimenofeitherintactorreconstitutedsoil.Specimensareconsolidatedandshearedincompressionwithdrainageataconstantrateofaxialdeformation(straincontrolled).1.2Thistestmethodprovidesforthecalculationofprinci-palstressesandaxialcompressionbymeasurementofaxialload,axialdeformation,andvolumetricchanges.1.3ThistestmethodprovidesdatausefulindeterminingstrengthanddeformationpropertiessuchasMohrstrengthenvelopes.Generally,threespecimensaretestedatdifferenteffectiveconsolidationstressestodefineastrengthenvelope.Thestressesshouldbespecifiedbytheengineerrequestingthetest.Atestonanewspecimenisrequiredforeachconsolida-tionstress.1.4Ifthistestmethodisusedoncohesivesoil,atestmaytakeweekstocomplete.1.5Thedeterminationofstrengthenvelopesandthedevel-opmentofrelationshipstoaidininterpretingandevaluatingtestresultsarebeyondthescopeofthistestmethodandmustbeperformedbyaqualified,experiencedprofessional.1.6AllobservedandcalculatedvaluesshallconformtotheguidelinesforsignificantdigitsandroundingestablishedinPracticeD6026.1.6.1Theproceduresusedtospecifyhowdataarecollected,calculated,orrecordedinthisstandardareregardedastheindustrystandard.Inaddition,theyarerepresentativeofthesignificantdigitsthatgenerallyshouldberetained.Theproce-duresuseddonotconsidermaterialvariations,purposeforobtainingthedata,specialpurposestudiesoranyconsiderationfortheuser’sobjectives;anditiscommonpracticetoincreaseorreducethesignificantdigitsofthereporteddatatobecommensuratewiththeseconsiderations.Itisbeyondthescopeofthistestst...
