ASTM_D_7300_-_11.pdf

Designation:D730011Standard Test Method forLaboratory Determination of Strength Properties of FrozenSoil at a Constant Rate of Strain1This standard is issued under the fixed designation D7300;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.INTRODUCTIONKnowledge of the stress-strain-strength behavior of frozen soil is of great importance for civilengineering construction in permafrost regions.The behavior of frozen soils under load is usually verydifferent from that of unfrozen soils because of the presence of ice and unfrozen water films.Inparticular,frozen soils are much more subject to creep and relaxation effects,and their behavior isstrongly affected by temperature change.In addition to creep,volumetric consolidation may alsodevelop in frozen soils having large unfrozen water or gas contents.As with unfrozen soil,the deformation and strength behavior of frozen soils depends oninterparticle friction,particle interlocking,and cohesion.In frozen soil,however,bonding of particlesby ice may be the dominant strength factor.The strength of ice in frozen soil is dependent on manyfactors,such as temperature,pressure,strain rate,grain size,crystal orientation,and density.At veryhigh ice contents(ice-rich soils),frozen soil behavior under load is similar to that of ice.In fact,forfine-grained soils,experimental data suggest that the ice matrix dominates when mineral volumefraction is less than about 50%.At low ice contents,however,(ice-poor soils),when interparticleforces begin to contribute to strength,the unfrozen water films play an important role,especially infine-grained soils.Finally,for frozen sand,maximum strength is attained at full ice saturation andmaximum dry density(1).21.Scope*1.1 This test method covers the determination of thestrength behavior of cylindrical specimens of frozen soil,subjected to uniaxial compression under controlled rates ofstrain.It specifies the apparatus,instrumentation,and proce-dures for determining the stress-strain-time,or strength versusstrain rate relationships for frozen soils under deviatoric creepconditions.1.2 Values stated in SI units are to be regarded as thestandard.1.3 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.3.1 For the purposes of comparing measured or calculatedvalue(s)with specified limits,the measured or calculatedvalue(s)shall be rounded to the nearest decimal or significantdigits in the specified limits.1.3.2 The procedures used to specify how data are collected/recorded or calculated,in this standard are regarded as theindustry standard.In addition,they are representative of thesignificant digits that generally should be retained.The proce-dures used do not consider material variation,purpose forobtaining the data,special purpose studies,or any consider-ations for the users objectives;and it is common practice toincrease or reduce significant digits of reported data to becommensurate with these considerations.It is beyond the scopeof this standard to consider significant digits used in analyticalmethods for engineering design.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.19 on Frozen Soils andRock.Current edition approved Nov.1,2011.Published January 2012.Originallyapproved in 2006.Last previous edition approved in 2006 as D730006.DOI:10.1520/D7300-11.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.*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 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:3D653 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 ConstructionD4083 Practice for Description of Frozen Soils(Visual-Manual Procedure)D6026 Practice for Using Significant Digits in GeotechnicalData3.Terminology3.1 Definitions:3.1.1 For definitions of common technical terms in thisstandard,refer to Terminology D653.3.1.2 Definitions of the components of freezing and thawingsoils shall be in accordance with the terminology in PracticeD4083.3.2 Definitions of Terms Specific to This Standard:3.2.1 The following terms are used in conjunction with thedetermination of the s