Designation:D5321/D5321M−14StandardTestMethodforDeterminingtheShearStrengthofSoil-GeosyntheticandGeosynthetic-GeosyntheticInterfacesbyDirectShear1ThisstandardisissuedunderthefixeddesignationD5321/D5321M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversaprocedurefordeterminingtheshearresistanceofageosyntheticagainstsoil,orageosyn-theticagainstanothergeosynthetic,underaconstantrateofdeformation.1.1.1Thetestmethodisintendedtoindicatetheperfor-manceoftheselectedspecimenbyattemptingtomodelcertainfieldconditions.Resultsobtainedfromthismethodmaybelimitedintheirapplicabilitytothespecificconditionsconsid-eredinthetesting.1.2Thetestmethodisapplicableforallgeosynthetics,withtheexceptionofgeosyntheticclayliners(GCLs)whichareaddressedinTestMethodD6243/D6243M.1.3Thetestmethodisnotsuitedforthedevelopmentofexactstress-strainrelationshipsforthetestspecimenduetothenon-uniformdistributionofshearingforcesanddisplacement.1.4ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.1.5Thisstandarddoesnotpurporttoaddressallthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:2D653TerminologyRelatingtoSoil,Rock,andContainedFluidsD698TestMethodsforLaboratoryCompactionCharacter-isticsofSoilUsingStandardEffort(12400ft-lbf/ft3(600kN-m/m3))D1557TestMethodsforLaboratoryCompactionCharacter-isticsofSoilUsingModifiedEffort(56,000ft-lbf/ft3(2,700kN-m/m3))D2435/D2435MTestMethodsforO...
