ASTM_D_7498_-_D_7498M_-_09_2022.pdf

Designation:D7498/D7498M09(Reapproved 2022)Standard Test Method forVertical Strip Drains Using a Large-Scale ConsolidationTest1This standard is issued under the fixed designation D7498/D7498M;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 is a performance test which measuresthe effectiveness of vertical strip drains on the time rates ofconsolidation of compressible soils from construction projectsites.1.1.1 It is expected that the design agency will be respon-sible for performing this test.It is not intended to be amanufacturer-performed test.1.2 This test method is applicable to all vertical strip drains.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system are not necessarily exact equivalents;therefore,toensure conformance with the standard,each system shall beused independently of the other,and values from the twosystems shall not be combined.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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization 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:2D4354 Practice for Sampling of Geosynthetics and RolledErosion Control Products(RECPs)for TestingD4439 Terminology for Geosynthetics3.Terminology3.1 DefinitionsFor definitions related to geosynthetics,seeTerminology D4439.3.2 Definitions of Terms Specific to This Standard:3.2.1 vertical strip drains,na geocomposite consisting ofa geotextile cover and drainage core installed vertically intosoil to provide drainage for accelerated consolidation of soils.4.Summary of Test Method4.1 This test method describes procedures for determiningthe effectiveness of vertical strip drains used under specifiedsoil conditions to enhance the time rate of consolidation ofcompressible soils.4.2 A specimen of the vertical strip drain is inserted in thetest chamber and compressible soil from the project site isremolded around the vertical strip drain,such that the drain isin a similar position as it would be on the project site.4.3 The top of the soil is sealed with a wax seal,such thatdrainage only occurs through the vertical strip drain.Thevertical strip drain protrudes up through the seal.4.4 Asand drainage blanket is placed on top of the wax seal,such that the vertical strip drain drains into the sand blanket.4.5 A rubber cup seal provides the means of applyingincremental loads in a similar manner to a standard soilsconsolidation test.4.6 A similar setup is used,only with a 50 mm 2 in.sanddrain in place of the vertical strip drain.4.7 The coefficients of consolidation are determined fromthe test results for both the vertical strip drain and the sanddrain.Time rates of consolidation are then compared.4.8 Persons performing this test shall have knowledge in theconsolidation testing of soils.5.Significance and Use5.1 As this is a time-intensive test,it should not be consid-ered as an acceptance test for commercial shipments ofprefabricated vertical strip drains.5.2 Prior to the development of vertical strip drains,when itwas desired to increase the rate of consolidation of a compress-ible soil on a construction project,large-diameter sand drains1This test method is under the jurisdiction of ASTM Committee D35 onGeosynthetics and is the direct responsibility of Subcommittee D35.03 on Perme-ability and Filtration.Current edition approved May 1,2022.Published May 2022.Originallyapproved in 2009.Last previous edition approved in 2014 as D7498/D7498M 09(2014)1.DOI:10.1520/D7498_D7498M-09R22.2For 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 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 Technical Barriers to Trade(TBT)Committee.1were installed.Vertical strip drains can be installed in areaswhe