1、Designation:D560708Standard 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 o
2、f 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 st
3、rength tests onrock specimens.It includes procedures for both intact rockstrength and sliding friction tests which can be performed onspecimens that are homogeneous,or have planes of weakness,including natural or artificial discontinuities.Examples of anartificial discontinuity include a rock-concre
4、te interface or a liftline from a concrete pour.Discontinuities may be open,partially or completely healed or filled(that is,clay fillings andgouge).Only one discontinuity per specimen can be tested.Thetest is usually conducted in the undrained state with an appliedconstant normal load.However,a cle
5、an,open discontinuitymay be free draining,and,therefore,a test on a clean,opendiscontinuity could be considered a drained test.During thetest,shear strength is determined at various applied stressesnormal to the sheared plane and at various shear displacements.Relationships derived from the test dat
6、a include shear strengthversus normal stress and shear stress versus shear displacement(shear stiffness).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 speci
7、men 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 determine
8、d are expressed interms of total stress,uncorrected for pore pressure.1.2 This standard applies to hard rock,soft rock,andconcrete.1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are mathematicalconversions to inch-pound units that are provided for
9、 informa-tion only and are not considered standard.1.4 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 reg
10、ulatory 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 Testin
11、g and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionE4 Practices for Force Verification of Testing MachinesE122 Practice for Calculating Sample Size to Estimate,WithSpecified Precision,the Average for a Characteristic of aLot or Process3.Terminology3.1 DefinitionsFor co
12、mmon definitions of terms used inthis standard,refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 apparent stressnominal stress,that is,external loadper unit area.It is calculated by dividing the externally appliedload by the nominal area.3.2.2 Asperity:3.2.2.1 qualit
13、ythe roughness of a surface.3.2.2.2 featurea surface irregularity ranging from sharp orangular to rounded or wavy.3.2.2.3 asperitiesthe collection of a surfaces irregulari-ties that account for the surfaces roughness.3.2.3 Discontinuity:3.2.3.1 An abrupt change,interruption,or break in theintegrity
14、or physical properties of rock,such as a beddingplane,fracture,cleavage,crack,joint,or fault.3.2.3.2 A gapped discontinuity consists of opposing rocksurfaces separated by an open or filled space.A tight discon-tinuity consists of opposing rock surfaces in intimate and1This test method is under the j
15、urisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics.Current edition approved July 1,2008.Published July 2008.Originally approvedin 1994.Last previous edition approved in 2006 as D5607 02(2006).DOI:10.1520/D5607-08.2For referenced
16、 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 section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 generally continuous contact;it may be valid to treat such adiscontinuity as a single surface.3.2.3.3 A di
