ASTM_D_4971_-_16.pdf

Designation:D497116Standard Test Method forDetermining In Situ Modulus of Deformation of Rock UsingDiametrically Loaded 76-mm(3-in.)Borehole Jack1This standard is issued under the fixed designation D4971;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 covers the estimation of in situmodulus of a rock mass at various depths and orientations.Information on time-dependent deformation may also be ob-tained.1.2 This test method covers testing in an N size drill holeand is more relevant to a borehole jack device designed for“hard rock”than for soft rock.1.3 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.3.1 The method used to specify how data are collected,calculated,or recorded in this standard is not directly related tothe accuracy to which the data can be applied in design or otheruses,or both.How one applies the results obtained using thisstandard is beyond its scope.1.4 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 informa-tion only and are not considered standard.1.5 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 ContainedFluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD6026 Practice for Using Significant Digits in GeotechnicalDataD6032 Test Method for Determining Rock Quality Designa-tion(RQD)of Rock Core3.Terminology3.1 Definitions:3.1.1 For definitions of common technical terms in thisstandard,refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 deformation,nchange in shape or size,(see Termi-nology D653).In this test method deformation is the change inthe diameter of the borehole.3.2.2 modulus of deformation,nratio of stress to strain fora material under given loading conditions;numerically equal tothe slope of the tangent or the secant of the stress-strain curve.3.2.2.1 DiscussionThe use of the term modulus of elas-ticity is recommended for materials that deform in accordancewith Hookes law,and the term modulus of deformation isrecommended for materials that deform otherwise,(see Termi-nology D653).In this test method,the modulus of deformationis calculated from the applied fluid pressure,the relativechange in hole diameter,a function of Poissons ratio,and aconstant.3.2.3 jack effciency,nratio of the jack plate pressure tothe applied hydraulic pressure.3.2.4 hard rock borehole jack,nthis refers to a specificborehole jack by the manufacture that has platens designed forharder rocks,goes to higher pressures than a soft rock boreholejack and whose displacement range is not exceeded at themaximum allowable pressure for the borehole jack.4.Summary of Test Method4.1 The drill logs for a drill hole hole to be tested areexamined.Specific depths and orientations in the drill hole areselected based upon the objectives of the test program.4.2 The borehole jack in the fully retracted position ispositioned at each location selected in the drill hole for the testprogram.The 76 mm(3 in.)jacks,(see Fig.1 and Fig.2),induce unidirectional pressure to the walls of a borehole bymeans of two opposed curved steel platens each covering a 901This 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 1989.Last previous edition approved in 2008 as D4971 08.DOI:10.1520/D4971-16.2For 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 section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 sector,over a length of 20 cm(8 in.)and pressure vers