Designation:D7300−18StandardTestMethodforLaboratoryDeterminationofStrengthPropertiesofFrozenSoilataConstantRateofStrain1ThisstandardisissuedunderthefixeddesignationD7300;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.INTRODUCTIONKnowledgeofthestress-strain-strengthbehavioroffrozensoilisofgreatimportanceforcivilengineeringconstructioninpermafrostregions.Thebehavioroffrozensoilsunderloadisusuallyverydifferentfromthatofunfrozensoilsbecauseofthepresenceoficeandunfrozenwaterfilms.Inparticular,frozensoilsaremuchmoresubjecttocreepandrelaxationeffects,andtheirbehaviorisstronglyaffectedbytemperaturechange.Inadditiontocreep,volumetricconsolidationmayalsodevelopinfrozensoilshavinglargeunfrozenwaterorgascontents.Aswithunfrozensoil,thedeformationandstrengthbehavioroffrozensoilsdependsoninterparticlefriction,particleinterlocking,andcohesion.Infrozensoil,however,bondingofparticlesbyicemaybethedominantstrengthfactor.Thestrengthoficeinfrozensoilisdependentonmanyfactors,suchastemperature,pressure,strainrate,grainsize,crystalorientation,anddensity.Inice-richsoils(thatis,soilswheretheratioofthemassoficecontainedintheporespacesoffrozensoilorrockmaterial,tothemassofsolidparticlesinthatmaterialishigh),frozensoilbehaviorunderloadissimilartothatofice.Infact,forfine-grainedsoils,experimentaldatasuggestthattheicematrixdominateswhenmineralvolumefractionislessthanabout50%.Atlowicecontents,however,(ice-poorsoils),wheninterparticleforcesbegintocontributetostrength,theunfrozenwaterfilmsplayanimportantrole,especiallyinfine-grainedsoils.Finally,forfrozensand,maximumstrengthisattainedatfullicesaturationandmaximumdrydensity(1).21.Scope1.1Thistestmethodcoversthedeterminationofthestrengthbehaviorofcylindricalspecimensoffrozensoil,subjectedtouniaxialcompressionundercontrolledratesofstrain.Itspe...
