ASTM_D_2166_-_D_2166M_-_16.pdf

Designation:D2166/D2166M16Standard Test Method forUnconfined Compressive Strength of Cohesive Soil1This standard is issued under the fixed designation D2166/D2166M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the determination of the uncon-fined compressive strength of cohesive soil in the intact,remolded,or reconstituted condition,using strain-controlledapplication of the axial load.1.2 This test method provides an approximate value of thestrength of cohesive soils in terms of total stresses.1.3 This test method is applicable only to cohesive materialswhich will not expel or bleed water(water expelled from thesoil due to deformation or compaction)during the loadingportion of the test and which will retain intrinsic strength afterremoval of confining pressures,such as clays or cementedsoils.Dry and crumbly soils,fissured or varved materials,silts,peats,and sands cannot be tested with this method to obtainvalid unconfined compression strength values.NOTE1The determination of the unconsolidated,undrained strengthof cohesive soils with lateral confinement is covered by Test MethodD2850.1.4 This test method is not a substitute for Test MethodD2850.1.5 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026,unless superseded by this standard.1.5.1 The procedures used to specify how data are collected/recorded and calculated in this test method are regarded as theindustry standard.In addition,they are representative of thesignificant digits that should generally 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 com-mensurate with these considerations.It is beyond the scope ofthis test method to consider significant digits used in analysismethods for engineering design.1.6 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.1.6.1 The gravitational system of inch-pound units is usedwhen dealing with inch-pound units.In this system,the pound(lbf)represents a unit of force(weight),while the unit for massis slugs.The rationalized slug unit is not given,unless dynamic(F=ma)calculations are involved.1.6.2 It is common practice in the engineering/constructionprofession to concurrently use pounds to represent both a unitof mass(lbm)and of force(lbf).This implicitly combines twoseparate systems of units;that is,the absolute system and thegravitational system.It is scientifically undesirable to combinethe use of two separate sets of inch-pound units within a singlestandard.As stated,this standard includes the gravitationalsystem of inch-pound units and does not use/present the slugunit for mass.However,the use of balances or scales recordingpounds of mass(lbm)or recording density in lbm/ft3shall notbe regarded as nonconformance with this standard.1.7 This standard does not purport to address all of thesafety problems,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 ContainedFluidsD854 Test Methods for Specific Gravity of Soil Solids byWater PycnometerD1587 Practice for Thin-Walled Tube Sampling of Fine-Grained Soils for Geotechnical PurposesD2216 Test Methods for Laboratory Determination of Water(Moisture)Content of Soil and Rock by MassD2488 Practice for Description and Identification of Soils(Visual-Manual Procedure)1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.05 on Strength andCompressibility of Soils.Current edition approved July 1,2016.Published July 2016.Originally approvedin 1963.Last previous edition approved in 2013 as D2166 13.DOI:10.1520/D2166_D2166M-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 States1 D2850 Test Method for Uncons