ASTM_D_5607_-_16.pdf

Designation:D560716Standard Test Method forPerforming Laboratory Direct Shear Strength Tests of RockSpecimens Under Constant Normal Force1This standard is issued under the fixed designation D5607;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method establishes requirements and labora-tory procedures for performing direct shear strength tests onrock specimens under a constant normal load.It includesprocedures for both intact rock strength and sliding frictiontests,which can be performed on specimens that arehomogeneous,or have planes of weakness,including natural orartificial discontinuities.Examples of an artificial discontinuityinclude a rock-concrete interface or a lift line from a concretepour.Discontinuities may be open,partially or completelyhealed or filled(that is,clay fillings and gouge).Only onediscontinuity per specimen can be tested.The test is usuallyconducted in the undrained state with an applied constantnormal load.However,a clean,open discontinuity may be freedraining,and,therefore,a test on a clean,open discontinuitycould be considered a drained test.During the test,shearstrength is determined at various applied stresses normal to thesheared plane and at various shear displacements.Relation-ships derived from the test data include shear strength versusnormal stress and shear stress versus shear displacement(shearstiffness).NOTE1The term“normal force”is used in the title instead of normalstress because of the indefinable area of contact and the minimal relativedisplacement between upper and lower halves of the specimen duringtesting.The actual contact areas during testing change,but the actual totalcontact surface is unmeasurable.Therefore nominal area is used forloading purposes and calculations.NOTE2Since this test method makes no provision for the measure-ment of pore pressures,the strength values determined are expressed interms of total stress,uncorrected for pore pressure.1.2 This standard applies to hard rock,medium rock,softrock,and concrete.1.3 This test method is only applicable to quasi-static testingof rock or concrete specimens under monotonic shearing witha constant normal load boundary condition.The constantnormal load boundary condition is appropriate for problemswhere the normal stress is constant along the discontinuity.Theconstant normal load boundary condition may not be appro-priate for problems where shearing is dilatancy controlled andthe normal stress is not constant along the discontinuity.1.4 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.4.1 The procedures used to specify how data are collected/recorded and calculated in this standard are regarded as theindustry standard.In addition,they are representative of thesignificant digits that generally should be retained.The proce-dures used do not consider material variation,purpose forobtaining data,special purpose studies,or any considerationsfor the users objectives;and it is common practice to increaseor reduce significant digits of reported data to commensuratewith these considerations.It is beyond the scope of these testmethods to consider significant digits used in analysis methodsfor engineering design1.5 UnitsThe values stated in SI units are to be regardedas standard.The values given in parentheses are mathematicalconversions to inch-pound units,which are provided forinformation only and are not considered standard.Reporting oftest results in units other than SI shall not be regarded asnonconformance with this test method.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil,Rock,and ContainedFluidsD2216 Test Methods for Laboratory Determination of Water(Moisture)Content of Soil and Rock by MassD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock as1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics.Current edition approved Dec.1,2016.Published January 2017.Originallyapproved in 1994.Last previous edition approved in 2008 as D5607 08.DOI:10.1520/D5607-16.2For 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.*A Summary of Changes sectio