ASTM_D_3148_-_02.pdf

Designation:D 3148 02Standard Test Method forElastic Moduli of Intact Rock Core Specimens in UniaxialCompression1This standard is issued under the fixed designation D 3148;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(e)indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the determination of elasticmoduli of intact rock core specimens in uniaxial compression.It specifies the apparatus,instrumentation,and procedures fordetermining the stress-axial strain and the stress-lateral straincurves,as well as Youngs modulus,E,and Poissons ratio,n.NOTE1This test method does not include the procedures necessary toobtain a stress-strain curve beyond the ultimate strength.1.2 For an isotropic material,the relation between the shearand bulk moduli and Youngs modulus and Poissons ratio are:G 5E21 1 n!(1)K 5E31 2 2n!(2)where:G=shear modulus,K=bulk modulus,E=Youngs modulus,andn=Poissons ratio.The engineering applicability of these equations is decreasedif the rock is anisotropic.When possible,it is desirable toconduct tests in the plane of foliation,bedding,etc.,and at rightangles to it to determine the degree of anisotropy.It is notedthat equations developed for isotropic materials may give onlyapproximate calculated results if the difference in elasticmoduli in any two directions is greater than 10%for a givenstress level.NOTE2Elastic moduli measured by sonic methods may often beemployed as preliminary measures of anisotropy.1.3 The test method given for determining the elasticconstants does not apply to rocks that undergo significantinelastic strains during the test,such as potash and salt.Theelastic moduli for such rocks should be determined fromunload-reload cycles,which is not covered by this test method.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 regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 653 Terminology Relating to Soil,Rock,and ContainedFluids2D 2216 Test Method for Laboratory Determination of Water(Moisture)Content of Soil and Rock2D 3740 Practice for Minimum Requirements for AgenciesEngaged in the Testing and/or Inspectionof Soil and RockUsed in Engineering Design and Construction2D 4543 Practice for Preparing Rock Core Specimens andDetermining Dimensional and Shape Tolerances2E 4 Practices for Load Verification of Testing Machines3E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method43.Terminology3.1 Definitions:See Terminology D 653 for general defini-tions.3.2 Definitions of Terms Specific to This Standard:3.2.1 bulk modulus,K FL-2average normal stress di-vided by the change in volume per original volume.3.2.2 shear modulus,G FL-2ratio of the shear stress tothe corresponding shear strain below the proportional limit.4.Summary of Test Method4.1 A rock core sample is cut to length,and the ends aremachined flat.The specimen is placed in a loading frame and,if required,heated to the desired test temperature.Axial load iscontinuously increased on the specimen,and deformation ismonitored as a function of load.5.Significance and Use5.1 The elastic constants are used to calculate the stress anddeformation in rock structures.5.2 The deformation and strength properties of rock coresmeasured in the laboratory usually do not accurately reflect1This 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 Jan.10,2002.Published April 2002.Originallypublished as D 3148 72.Last previous edition D 3148 96.2Annual Book of ASTM Standards,Vol 04.08.3Annual Book of ASTM Standards,Vol 03.01.4Annual Book of ASTM Standards,Vol 14.02.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.large-scale in situ properties,because the latter are stronglyinfluenced by joints,faults,inhomogeneities,weakness planes,and other factors.Therefore,laboratory values for intactspecimens must be employed with proper judgment in engi-neering applications.NOTE3The quality of the result produced by this standard isdependent on the competence of the personnel performing it,and thesuitability of the equipment and facilities used.Agencies that meet thecriteria of Practice D 3740 are generally considered capable of competentand objective testing/sampling/inspection/and the like.Users of thisstandard are cautioned that compliance with Practice D 3740 does not initself assure reliable results.Reliable results depend n many f