ASTM_D_5321_-_D_5321M_-_14.pdf

Designation:D5321/D5321M14Standard Test Method forDetermining the Shear Strength of Soil-Geosynthetic andGeosynthetic-Geosynthetic Interfaces by Direct Shear1This standard is issued under the fixed designation D5321/D5321M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers a procedure for determining theshear resistance of a geosynthetic against soil,or a geosyn-thetic against another geosynthetic,under a constant rate ofdeformation.1.1.1 The test method is intended to indicate the perfor-mance of the selected specimen by attempting to model certainfield conditions.Results obtained from this method may belimited in their applicability to the specific conditions consid-ered in the testing.1.2 The test method is applicable for all geosynthetics,withthe exception of geosynthetic clay liners(GCLs)which areaddressed in Test Method D6243/D6243M.1.3 The test method is not suited for the development ofexact stress-strain relationships for the test specimen due to thenon-uniform distribution of shearing forces and displacement.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.5 This standard does not purport to address all the safetyconcerns,if any,associated with its use.It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD698 Test Methods for Laboratory Compaction Character-istics of Soil Using Standard Effort(12 400 ft-lbf/ft3(600kN-m/m3)D1557 Test Methods for Laboratory Compaction Character-istics of Soil Using Modified Effort(56,000 ft-lbf/ft3(2,700 kN-m/m3)D2435/D2435M Test Methods for One-Dimensional Con-solidation Properties of Soils Using Incremental LoadingD2487 Practice for Classification of Soils for EngineeringPurposes(Unified Soil Classification System)D3080/D3080M Test Method for Direct Shear Test of SoilsUnder Consolidated Drained ConditionsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4354 Practice for Sampling of Geosynthetics and RolledErosion Control Products(RECPs)for TestingD4439 Terminology for GeosyntheticsD6243/D6243M Test Method for Determining the Internaland Interface Shear Strength of Geosynthetic Clay Linerby the Direct Shear Method3.Terminology3.1 Definitions:For definitions of terms relating to soil androck,refer to Terminology D653.For definitions of termsrelating to geosynthetics,refer to Terminology D4439.3.2 Definitions of Terms Specific to This Standard:3.2.1 adhesion,ca,nthe y-intercept of the Mohr-Coulombstrength envelope.3.2.2 atmosphere for testing geosynthetics,nair main-tained at a relative humidity between 50 and 70%andtemperature of 21 6 2C 70 6 4F.3.2.3 Mohr-Coulomb friction angle,n(angle of frictionof a material or between two materials,)the angle defined bythe least-squares,“best-fit”straight line through a definedsection of the shear strength-normal stress failure envelope;thecomponent of the shear strength indicated by the term,inCoulombs equation,=ca+n*tan()(see 12.6).3.2.3.1 DiscussionThe end user is cautioned that someorganizations(for example,FHWA,AASHTO along with stateagencies who use these documents)are currently using theGreek letter,Delta(),to designate wall-backfill interface1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechani-cal Properties.Current edition approved Jan.1,2014.Published January 2014.Originallyapproved in 1992.Last previous edition approved in 2013 as D5321/D5321M13DOI:10.1520/D5321_D5321M-14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 friction angle and the Greek letter,Rho(),to designate theinterface friction angle between geosynthetics and soil.3,43.2.4 Mohr-Coulomb shear strength envelope,nthe leastsquares,“best fit”straight line through a defined section of theshear strength-normal stress failure envelope described by theequation,=ca+n*tan()(see 12.6).The envelope can bedescribed for any chosen she