ASTM_D_4553_-_08.pdf

Designation:D455308Standard Test Method forDetermining In Situ Creep Characteristics of Rock1This standard is issued under the fixed designation D4553;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 preparation,equipment,testprocedure,and data documentation for determining in situcreep characteristics of a rock mass using a rigid platesubjected to controlled loading.1.2 This test method is designed to be conducted in anunderground opening;however,with suitable modifications,this test could be conducted at the surface.1.3 The test is usually conducted parallel or perpendicular tothe anticipated axis of thrust,as dictated by the design load orother orientations,based upon the application.1.4 Flexible plate apparatus can be used if the anticipatedcreep displacement is within the tolerance of the travel of theflat jacks.1.5 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.6This 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.For specificprecaution statements,see Section 8.2.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 ConstructionD4394 Test Method for Determining In Situ Modulus ofDeformation of Rock Mass Using Rigid Plate LoadingMethodD4403 Practice for Extensometers Used in Rock3.Terminology3.1 DefinitionsSee Terminology D653 for general defini-tions.3.2 Definitions of Terms Specific to This Standard:3.2.1 creepa time-dependent displacement of a platepushed into the surface of the rock by a constant normal load.It is not directly related with laboratory creep data because ofthe nonuniformity of stress within the rock mass underneaththe plate.3.2.2 displacementmovement of the rigid plate,grout pad,or rock in response to and in the same direction as the appliedload.3.2.3 loadtotal force acting on the rock face.3.2.4 rigid plateplate with a deflection of less than 0.0005in.(0.0125 mm)from the center to the edge of the plate whenmaximum load is applied.4.Summary of Test Method4.1 Areas on two opposing faces of a test opening areflattened,smoothed,and made parallel.4.2 A grout pad and rigid metal plate are installed againsteach face and a hydraulic loading system is placed between therigid plates.4.3 The two faces are rapidly loaded to the desired creepload,without shock,the load maintained,and the displacementof the plate measured as a function of time.5.Significance and Use5.1 Results of this test method are used to predict time-dependent deformation characteristics of a rock mass resultingfrom loading.It is a test that may be required depending onrock type or anticipated loads,or both.5.2 This test method may be useful in structural designanalysis where loading is applied over an extensive period.5.3 This test method is normally performed at ambienttemperature,but equipment can be modified or substituted foroperations at other temperatures.1This 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 July 1,2008.Published July 2008.Originally approvedin 1985.Last previous edition approved in 2006 as D4553 02(2006).DOI:10.1520/D4553-08.2For 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 States1 5.4 Results of this test method may be useful in verifyinglaboratory creep data and structural mathematical modelinganalyses.5.5 Creep characteristics are determined under a nonuni-form state of stress.5.6 If during a field investigation,time-dependent charac-teristics are detected,then an in situ creep test shall beperformed.NOTE1The 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 D3740 are generally considered capable of competentand objective testing/sampl