ASTM_D_7499_-_D_7499M_-_09_2014.pdf

Designation:D7499/D7499M09(Reapproved 2014)Standard Test Method forMeasuring Geosynthetic-Soil Resilient Interface ShearStiffness1This standard is issued under the fixed designation D7499/D7499M;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.Scope1.1 This test method details how cyclic loading is applied togeosynthetics embedded in soil to determine the apparentstiffness of the soilgeosynthetic interface.1.2 Resilient interface shear stiffness describes the shearstiffness between a geosynthetic and its surrounding soil underconditions of small cyclic loads.1.3 This test method is intended to provide properties fordesign.The test method was developed for mechanistic em-pirical pavement design methods requiring input of the resilientinterface shear stiffness.The use of this parameter from thistest method for other applications involving cyclic loadingshould be evaluated on a case-by-case basis.It can also be usedto compare different geosynthetics,soil types,etc.,and therebybe used as a research and development test procedure.1.4 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.1.5 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.This standard mayinvolve hazardous materials,and equipment.2.Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD653 Terminology Relating to Soil,Rock,and ContainedFluidsD3080/D3080M Test Method for Direct Shear Test of SoilsUnder Consolidated Drained ConditionsD4439 Terminology for GeosyntheticsD4354 Practice for Sampling of Geosynthetics and RolledErosion Control Products(RECPs)for Testing3.Terminology3.1 For definitions of other terms used in this test methodrefer to Terminologies D123,D653,and D4439.3.2 Definitions of Terms Specific to This Standard:3.2.1 apertures,nthe open spaces in geogrids whichenable soil interlocking to occur.3.2.2 atmosphere for testing geosynthetics,nair main-tained at a relative humidity of 60 6 10%and a temperatureof 21 6 2C 70 6 4F.3.2.3 cross-machine direction,nthe direction in the planeof the geosynthetic perpendicular to the direction of manufac-ture.3.2.4 failure,nan arbitrary point at which a materialceases to be functionally capable of its intended use.3.2.5 geosynthetic,na planar product manufactured frompolymeric material used with soil,rock,earth,or other geo-technical engineering related material as an integral part of aman-made project,structure,or system.3.2.6 geosynthetic-soil resilient interface shear stiffness,na parameter that describes the apparent stiffness of theinterface between the soil and the geosynthetic determined bycalculating the slope of the shear stress,shear displacementcurve as the embedded geosynthetic is subjected to a cyclicload.3.2.7 junction,nthe point where geogrid ribs are intercon-nected in order to provide structure and dimensional stability.3.2.8 machine direction,nthe direction in the plane of thegeosynthetic parallel to the direction of manufacture.3.2.9 pullout,nthe movement of a geosynthetic over itsentire embedded length,with initial pullout occurring when theback of the specimen moves,and ultimate pullout occurringwhen the movement is uniform over the entire embeddedlength.1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechani-cal Properties.Current edition approved Sept.1,2014.Published September 2014.Originallyapproved in 2009.Last previous edition approved in 2009 as D7499/D7499M09.DOI:10.1520/D7499_D7499M-09R14.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.10 pullout force,(kN),nforce required to pull ageosynthetic out of the soil during a pullout test.3.2.11 pullout resistance,(kN/m),nthe pullout force perwidth of geosynthetic measured at a specified condition ofdisplacement.3.2.12 rib,nthe continuous elements of a geogrid whichare either in the machine or cross-machine direction asmanufactured.3.2.13 wire gage,na displacement gage consisting of anon extensible wire att