Designation:D4719−20StandardTestMethodsforPreboredPressuremeterTestinginSoils1ThisstandardisissuedunderthefixeddesignationD4719;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thistestmethodcoverspressuremetertestingofsoilsatagivendepthinthegroundwithinasuitableprebored,opentestcavity.Thepressuremetertestisaninsitu,stress-straintestperformedonthewallofatestcavityusingacircularcylindricalprobethatisexpandedradially.Toobtainviabletestresults,disturbanceofthetestcavitymustbeminimizedwithminimalclearancebetweenthediameteroftheprobeandthetestcavity.Alternatively,whenpreboringdoesnotprovideanacceptabletestcavity,theprobemaybedirectlyinsertedintothegroundtoformthetestcavity.1.2Thistestmethodincludestheprocedurefortestcavitypreparation,insertingtheprobe,andconductingpressuremetertestsinbothgranularandcohesivesoils,butdoesnotincludehighpressuretestinginrock.Knowledgeofthetypeofsoiltobetestedisnecessaryforassessmentof(1)themethodofpreparingthetestcavity,(2)theinterpretationofthetestdata,and(3)theacceptabilityofthetestresults.1.3Thistestmethoddoesnotcovertheself-boringpressuremeter,forwhichtheholeisdrilledbyamechanicalorjettingtoolinsidethehollowcoreoftheprobe.Thistestmethodislimitedtothetypeofpressuremeterthatisinsertedintopredrilledboreholesor,undercertaincircumstances,isinsertedbydrivingorpushing.1.4Twoalternativetestingproceduresareprovidedasfollows:1.4.1ProcedureA—EqualPressureIncrements1.4.2ProcedureB—EqualVolumeIncrementsNOTE1—Pressuremetertestsperformedinrockorusingtheself-boringpressuremeterfollowsimilartestprocedurestothosedescribedherein,butdonotfallwithinthescopeofthistestmethod.NOTE2—Strain-controlledtestsalsocanbeperformed,wherebytheprobevolumeisincreasedataconstantrateandcorrespondingpressuresaremeasured.Strain-controlledtestsmayyielddiff...
