1、Designation: D6467 131Standard Test Method forTorsional Ring Shear Test to Determine Drained ResidualShear Strength of Cohesive Soils1This standard is issued under the fixed designation D6467; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、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.1NOTEEditorially updated units of measurement statement in April 2018.1. Scope*1.1 This test method provides
3、 a procedure for performing atorsional ring shear test under a drained condition to determinethe residual shear strength of cohesive soils. An intact speci-men can be used for testing. However, obtaining a natural slipsurface specimen, determining the direction of field shearing,and trimming and ali
4、gning the usually non-horizontal shearsurface in the ring shear apparatus is difficult. As a result, thistest method focuses on the use of a reconstituted specimen tomeasure the residual strength. This test method is performed bydeforming a presheared, reconstituted specimen at a controlleddisplacem
5、ent rate until the constant drained shear resistance isoffered on a single shear plane determined by the configurationof the apparatus. An unlimited amount of continuous sheardisplacement can be achieved to obtain a residual strengthcondition. Generally, three or more normal stresses are appliedto a
6、 test specimen to determine the drained residual failureenvelope. A separate test specimen may be used for eachnormal stress.1.2 A shear stress-displacement relationship may be ob-tained from this test method. However, a shear stress-strainrelationship or any associated quantity, such as modulus,can
7、not be determined from this test method because soilextrusion 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.1.3 The selection of normal stresses and determination ofthe she
8、ar strength envelope for design analyses and the criteriato interpret and evaluate the test results are the responsibility ofthe engineer or office requesting the test.1.4 The values stated in SI units are to be regarded asstandard. The values given in parentheses after SI units areprovided for info
9、rmation only and are not considered standard.1.5 All measured and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is therespo
10、nsibility of the user of this standard to establish appro-priate safety, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-iza
11、tion established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D422 Test Method for Particle-Size Analysis of Soils
12、(With-drawn 2016)3D653 Terminology Relating to Soil, Rock, and ContainedFluidsD854 Test Methods for Specific Gravity 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 Consolidatio
13、nProperties of Soils Using Incremental LoadingD2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D3080 Test Method for Direct Shear Test of Soils UnderConsolidated Drained ConditionsD3740 Practice for Minimum Requirements for AgenciesEngaged in Tes
14、ting and/or Inspection of Soil and Rock asUsed in Engineering Design and Construction1This 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 May 1, 2013.
15、Published July 2013. Originally approvedin 1999. Last previous edition approved in 2006 as D6467 06a. DOI: 10.1520/D6467-13E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information
16、, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
17、PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization
18、 Technical Barriers to Trade (TBT) Committee.1D4318 Test Methods for Liquid Limit, Plastic Limit, andPlasticity Index of SoilsD6026 Practice for Using Significant Digits in GeotechnicalData3. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, refer to Terminology D653.3.2 De
19、finitions of Terms Specific to This Standard:3.2.1 consolidatedsoil specimen condition after primaryconsolidation under a specific normal stress.3.2.2 preshearedsoil specimen condition after shearing toat least one revolution of the ring in the direction of shear tocreate a failure surface prior to
20、drained shearing.3.2.3 residual shear forcethe shear force is the averageforce being applied to the specimen when the shear resistanceneither increases nor decreases with continued shear displace-ment.3.2.4 residual shear strengththe minimum constant resis-tance of soil to shear along a fully develo
21、ped failure surfaceand equals the residual shear force divided by the cross-sectional area of the specimen.3.2.5 drained residual strength statethe state at which asoil exhibits residual shear strength and shear stress sheardisplacement relationship becomes almost horizontal.4. Summary of Test Metho
22、d4.1 This test method consists of placing the specimen in theannular specimen container, applying a predetermined normalstress through the top loading platen, providing for wetting anddraining of the specimen (optional); consolidating the speci-men under the normal stress; decreasing the normal stre
23、ss toyield an overconsolidated specimen; preshearing the specimenby rotating the specimen container against the top loadingplaten for one revolution; applying a constant rate of sheardeformation rotation; and measuring the torque/shearing forceand rotation displacement until a constant value of shea
24、ringresistance is reached.5. Significance and Use5.1 The ring shear test is suited to the relatively rapiddetermination of drained residual shear strength because of theshort drainage path through the thin specimen, and the capa-bility of testing one specimen under different normal stresses toquickl
25、y obtain a shear strength envelope.5.2 The test results are primarily applicable to assess theshear strength in slopes that contain a preexisting shear surface,such as old landslides, soliflucted slopes, and sheared beddingplanes, joints, or faults.5.3 The apparatus allows a reconstituted specimen t
26、o beoverconsolidated and presheared prior to drained shearing.This simulates the field conditions that lead to a preexistingshear surface along which the drained residual strength can bemobilized.5.4 The ring shear device keeps the cross-sectional area ofthe shear surface constant during shear and s
27、hears the specimencontinuously in one rotational direction for any magnitude ofdisplacement. This allows clay particles to become orientedparallel to the direction of shear and a residual strengthcondition to develop.NOTE 1Notwithstanding the statements on precision and bias con-tained in this test
28、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 PracticeD3740 are generally considered capable of competent testing. Users ofthis test method are caution
29、ed that compliance with Practice D3740 doesnot ensure reliable testing. Reliable testing depends on several factors;Practice D3740 provides a means of evaluating some of those factors.6. Apparatus6.1 Shear Device, to hold the specimen securely betweentwo porous discs. The shear device provides a mea
30、n forapplying a normal stress to the faces of the specimen, formeasuring changes in thickness of the specimen, for permittingdrainage of water through the porous discs at the top andbottom boundaries of the specimen, and for submerging thespecimen in water. The device is capable of applying a torque
31、to the specimen along a shear plane parallel to the faces of thespecimen. A number of different ring shear devices are com-mercially available, in practice, or are being developed so ageneral description of a ring shear device is presented withoutschematic diagrams. The location of the shear plane d
32、ependson the configuration of the apparatus. As a result, the shearplane may be located near a soil/porous disc interface or at themid-height of the specimen if an upper ring can be separatedfrom a bottom ring as is done in a direct shear box. The deviceshall have low friction along the inner and ou
33、ter walls of thespecimen container developed during shearing. Friction maybe reduced by having the shear plane occur at the top of thespecimen container, modifying the specimen container wallswith low-friction material. The frames that hold the specimenshall be sufficiently rigid to prevent their di
34、stortion duringshearing. The various parts of the shear device shall be made ofa material such as stainless steel, bronze, or coated aluminumthat is not subject to corrosion by moisture or substances withinthe soil. Dissimilar metals, which may cause galvanic action,are not permitted.6.2 Specimen Co
35、ntainer, a device containing an annularcavity for the soil specimen with an inside diameter not lessthan 50 mm (2 in.) and an inside to outside diameter ratio notless than 0.6.The container has provisions for drainage throughthe top and bottom. The initial specimen depth, before con-solidation and p
36、reshearing, is not less than 5 mm (0.2 in.). Themaximum particle size is limited to 10 % of the initialspecimen height as stated in the test specimen description.6.3 Torque Arm/Loading Platen Assembly, may have differ-ent bearing stops for the proving rings, load cells, or force ortorque transducers
37、 to provide different options for the torquemeasurement.6.4 Porous Discs, two bronze or stainless steel porous discsmounted on the top loading platen and the bottom of thespecimen container cavity to allow drainage from the soilspecimen along the top and bottom boundaries. The inserts aidin transfer
38、 of shear stress to the top and bottom boundaries ofD6467 1312the specimen. The inserts must be sufficiently serrated todevelop a strong interlock with the soil specimen. The perme-ability of the inserts shall be substantially greater than that ofthe soil, but shall be textured fine enough to preven
39、t excessiveintrusion of the soil into the pores of the insert. The outer andinner diameters of the inserts shall be 0.1 mm (0.004 in.) less,and greater than those of the specimen annular cavity, respec-tively. The serration should have a depth of between 10 and15 % of the initial specimen height. Th
40、e porous discs shall beclean and free from cracks, chips, and nonuniformities. Newporous discs should be boiled for at least 10 minutes and left inthe water to cool to ambient temperature before use. Immedi-ately after each use, clean the porous discs with a nonabrasivebrush and boil to remove clay
41、particles that may reduce theirpermeability.NOTE 2Exact criteria for porous disc texture and permeability havenot been established. The grade of the porous disc shall be fine enough toprevent intrusion of soil into the pores. For normal soil testing, medium-grade inserts with a permeability of about
42、 5.0 104to 1.0 103cm/s(0.5 to 1.0 103ft/year) are appropriate for testing silts and clays. It isimportant that the permeability of the porous disc is not reduced by thecollection of soil particles in the pores of the insert; hence frequentchecking and cleaning (by flushing and boiling, or by ultraso
43、nic cleaning)is required to ensure that the permeability is not reduced.6.5 Loading Devices:6.5.1 Device for Applying and Measuring the NormalForceNormal force is usually applied by a lever-loadingyoke that is activated by dead weights (masses) or by anyautomatic loading mechanism. The device shall
44、be capable ofrapidly applying and maintaining the normal force to within61 % of the specified force.6.5.2 Device for Shearing the SpecimenThis device shallbe capable of shearing the specimen at a uniform rate ofrotation, with less than 65 % deviation. The rate to be applieddepends upon the consolida
45、tion characteristics of the soil (see9.5.1). The rate is usually maintained with an electric motorand gear box arrangement.6.6 Shear Force Measurement Device, two proving rings,load cells, in combination with a lever arm or a torquetransducers accurate to measure a force of 0.2 N (0.05 lbf).6.7 Wate
46、r Bath, container for the shear device and waterneeded to inundate the specimen.6.8 Controlled High-Humidity EnviromentFor preparingthe specimen, such that the water content gain or loss duringspecimen rehydration is minimized.6.9 Deformation IndicatorsDial gage, or other suitabledevice, capable of
47、measuring the change in thickness of thespecimen, with a sensitivity of 0.0025 mm (0.0001 in.). Etchedscale on circumference of the ring base to measure the degreestraveled, and thus the shear displacement, or other methodscapable of obtaining a sensitivity of 2.6.10 Equipment for Determination of W
48、ater Content, inaccordance in Test Method D2216.6.11 Miscellaneous Equipment, including timing devicewith a second hand, site-specific, test water (distilled ordemineralized), mortar, pestle, spatulas, razor blades,straightedge, and so forth.7. Test Specimen7.1 The sample used for specimen preparati
49、on is to besufficiently large so that a ring shear specimen and specimensfor index property tests can be prepared.7.2 If an intact specimen is desired, the sample obtainedfrom the shear surface should be trimmed to produce anannular specimen. Trimming of specimen can be accomplishedusing an annular trimming ring to facilitate trimming andinsertion of the specimen into the annular specimen container.A field shear surface may consist of small seams of clayeymaterial surrounded by material with a coarser gradation. If so,only the clayey shear zone material sh
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