ASTM_D_4405_-_04.pdf

Designation:D 4405 04Standard Test Method forCreep of Soft Rock Core Specimens in UniaxialCompression at Ambient or Elevated Temperature1This standard is issued under the fixed designation D 4405;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 creep behavior of intactcylindrical soft rock core specimens in uniaxial compression.Itspecifies the apparatus,instrumentation,and procedures fordetermining the strain as a function of time under sustainedload.Soft rocks include such materials as salt and potash,which often exhibit very large strain at failure.1.2 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D 6026.1.2.1 The method used to specifiy 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.1.3 The values stated SI units are to be regarded as thestandard.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:2D 653 Terminology Relating to Soil,Rock,and ContainedFluidsD 2113 Practice for Diamond Core Drilling for Site Inves-tigationD 2216 Test Method for Laboratory Determination of Water(Moisture)Content of Soil and RockD 3740 Practice for Minimum Requirements for AgenciesEngaged in the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and ConstructionD 4543 Practice for Preparing Rock Core Specimens andDetermining Dimensional and Shape TolerancesD 5079 Practices for Preserving and Transporting RockCore SamplesD 6026 Practice for Using Significant Digits in Geotechni-cal DataE 4 Practices for Load Verification of Testing MachinesE 122 Practice for Choice of Sample Size to Estimate aMeasure of Quality for a Lot or Process3.Terminology3.1 Refer to Terminology D 653 for specific definitions.4.Summary of Test Method4.1 A section of rock core is cut to length and the ends aremachined flat to produce a cylindrical test specimen.Thespecimen is placed in a loading frame and,if required,heatedto the desired test temperature.Axial load is rapidly applied tothe specimen and sustained.Deformation is monitored as afunction of elapsed time.5.Significance and Use5.1 There are many underground structures that are createdfor permanent or long-term use.Often these structures aresubjected to an approximately constant load.Creep testsprovide quantitative parameters for the stability analysis ofthese structures.5.2 The deformation and strength properties of rock coresmeasured in the laboratory usually do not accurately reflectlarge-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.NOTE1Notwithstanding the statements on precision and bias con-tained in this test method;the precision of this test method is dependenton the competence of the personnel performing it,and the suitability of theequipment and facilities used.Agencies that meet the criteria of PracticeD 3740 are generally considered capable of competent and objectivetesting.Users of this test method are cautioned that compliance with1This 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.1,2004.Published January 2004.Originallyapproved in 1993.Last previous edition approved in 1998 as D 4405 93(1998).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.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.Practice D 3740 does not in itself assure reliable testing.Reliable testingdepends on many factors;Practice D 3740 provides a means of evaluatingsome of these factors.6.Apparatus6.1 Loading DeviceThe loading device shall be of suffi-cient capacity to apply load at a rate conforming to therequirements specified in 10.5 and shall be able to maintain thespecified load within 2%.It shall be verified at suitable timeintervals in a