1、Designation:D760810Standard Test Method forTorsional Ring Shear Test to Determine Drained FullySoftened Shear Strength and Nonlinear Strength Envelopeof Cohesive Soils(Using Normally Consolidated Specimen)for Slopes with No Preexisting Shear Surfaces1This standard is issued under the fixed designati
2、on D7608;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 reapprova
3、l.1.Scope1.1 This test method provides a procedure for performing atorsional ring shear test under a drained condition to determinethe fully softened shear strength and nonlinear strength enve-lope of cohesive soils.The fully softened strength is used toevaluate the stability of slopes that do not h
4、ave a preexistingshear surface.In addition,the fully softened shear strengthcorresponds to the peak shear strength of a normally consoli-dated specimen.This test method focuses on the use of areconstituted specimen to measure the fully softened strength.This test method is performed by shearing a no
5、rmally consoli-dated,reconstituted specimen at a controlled displacement rateuntil the peak shear resistance has been obtained.Generally,the drained fully softened failure envelope is determined atthree or more effective normal stresses.A separate test speci-men must be used for each normal stress t
6、o measure the fullysoftened strength otherwise a post-peak or even residualstrength will be measured if the same specimen is used becauseof the existence of a shear surface.1.2 The ring shear apparatus allows a reconstituted speci-men to be normally consolidated at the desired normal stressprior to
7、drained shearing.This simulates the field conditionsunder which the fully softened strength develops in overcon-solidated clays,claystones,mudstones,and shales.1.3 A shear stress-displacement relationship may be ob-tained from this test method.However,a shear stress-strainrelationship or any associa
8、ted quantity,such as modulus,cannot be determined from this test method because possiblesoil extrusion and volume change prevents defining the heightneeded in the shear strain calculations.As a result,shear straincannot be calculated but shear displacement can be calculated.1.4 The selection of norm
9、al stresses and final determinationof the shear strength envelope for design analyses and thecriteria to interpret and evaluate the test results are theresponsibility of the engineer or office requesting the test.1.5 The values stated in SI units are to be regarded as thestandard.The values given in
10、 parentheses are mathematicalconversions to inch-pound units that are provided for informa-tion only and are not considered standard.1.6 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 establis
11、h appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D422 Test Method for Particle-Size Analysis of SoilsD653 Terminology Relating to Soil,Rock,and ContainedFluidsD854 Test Methods for Specific Gr
12、avity of Soil Solids byWater PycnometerD2216 Test Methods for Laboratory Determination of Water(Moisture)Content of Soil and Rock by MassD2435 Test Methods for One-Dimensional ConsolidationProperties of Soils Using Incremental LoadingD2487 Practice for Classification of Soils for EngineeringPurposes
13、(Unified Soil Classification System)D3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4318 Test Methods for Liquid Limit,Plastic Limit,andPlasticity Index of SoilsD6026 Practice for Using Significan
14、t Digits in GeotechnicalDataD6467 Test Method for Torsional Ring Shear Test to Deter-mine Drained Residual Shear Strength of Cohesive Soils1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.05 on Strength andCompressi
15、bility of Soils.Current edition approved May 15,2010.Published July 2010.DOI:10.1520/D760810.2For 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 Summa
16、ry page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.Terminology3.1 DefinitionsFor definitions of technical terms used inthis test method,refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 consolidatedsoil specimen condition after primaryconsolidation under a specific normal stress.3.2.2 fully softened shear forcethe shear force beingapplied to the specimen when the shear resista
