1、Designation: D6102 15Standard Guide forInstallation of Geosynthetic Clay Liners1This standard is issued under the fixed designation D6102; 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 paren
2、theses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers directions for the installation ofgeosynthetic clay liners (GCLs) under field conditions typi-cally present in environmental lining
3、applications.1.2 This guide contains general installation guidelines. It isnot intended to replace project-specific installation require-ments as found in the contract drawings or specifications. Inthe event of a conflict, the requirement of the project specifi-cations will supersede the requirement
4、s of this guide.1.3 This guide does not purport to establish specific proce-dure for all climatic, geographical, hydraulic, or topographicalconditions that may exist at a site. Appropriate installationprocedures under atypical field conditions should be modifiedas necessary to maintain the integrity
5、 of the GCL and adjacentlining system components.1.4 Different GCLs have different materials of constructionwith different physical properties. The procedures contained inthis guide, therefore, may not be universally applicable to allGCLs under all field conditions.1.5 The values stated in SI units
6、are to be regarded asstandard. No other units of measurement are included in thisstandard.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 establish appro-priate safety and health practic
7、es and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and ContainedFluidsD4439 Terminology for GeosyntheticsD5888 Guide for Storage and Handling of GeosyntheticClay Liners2.2 GRI Document:3GRI-GC
8、L-5 Standard Guide for Design Considerations forGeosynthetic Clay Liners (GCLs) in Various Applications3. Terminology3.1 Definitions: For definitions of other geosynthetic termsused in this guide, refer to Terminology D4439. For definitionsof soils terms, refer to Terminology D653.3.2 Definitions of
9、 Terms Specific to This Standard:3.2.1 fresh water, nwater with a salinity less than 0.5 partsper thousand.3.2.2 geosynthetic clay liner (GCL), na manufacturedhydraulic barrier consisting of clay bonded to a layer or layersof geosynthetics.4. Significance and Use4.1 For optimum performance, GCLs mus
10、t be installed in amanner that does not impact their physical, mechanical, orhydraulic properties.4.2 This guide identifies the proper installation proceduresand equipment for use by GCL designers, inspectors, andinstallers.5. Procedure5.1 The methods and equipment used for placement of theGCL can v
11、ary, but the primary objective of the process is tominimize the potential for GCL damage. The placementmethods and equipment should be evaluated appropriatelywithin this context.5.2 Subgrade Preparation:5.2.1 For projects where the GCL is to be placed over anearthen subgrade, the subgrade surface mu
12、st be prepared andapproved prior to installation in accordance either with projectspecifications or with this guide. The surface should be firmand unyielding, with no abrupt elevation changes, voids andcracks, ice, or standing water.1This guide is under the jurisdiction ofASTM Committee D35 on Geosy
13、ntheticsand is the direct responsibility of Subcommittee D35.04 on Geosynthetic ClayLiners.Current edition approved May 1, 2015. Published July 2015. Originally approvedin 1997. Last previous edition approved in 2012 as D610212. DOI: 10.1520/D6102-15.2For referenced ASTM standards, visit the ASTM we
14、bsite, 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.3Available from Geosynthetic Institute, 475 Kedron Avenue, Folsom, PA19033-1208, http:/www.geosynthetic-instit
15、ute.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.2.2 The subgrade surface should be smooth and free ofvegetation, sharp-edged rocks, stones, sticks, constructiondebris, and other foreign matter that could contact the GCL.The
16、subgrade surface shall be compacted in accordance withthe project specifications. At a minimum, the subgrade shouldbe rolled with a smooth-drum compactor of sufficient weight toremove any excessive wheel ruts, footprints, or other abruptgrade changes. Excessive rutting should be clearly defined andq
17、uantified. In some cases 25 mm is the maximum rut depthallowed. Furthermore, all protrusions extending more than 12mm from the subgrade surface shall either be removed,crushed, or pushed into the surface with a smooth-drumcompactor.5.3 GCL Placement:5.3.1 All handling of the GCL at the job site shou
18、ld beconducted in accordance with Guide D5888.5.3.2 GCL rolls are to be delivered to the working area ofthe site in their original packaging. Immediately prior todeployment, the packaging shall be carefully removed withoutdamaging the GCL.NOTE 1The orientation of the GCL (that is, which side faces u
19、p) maybe important and shall be in accordance with the engineers requirements.5.3.3 No equipment that could damage the GCL shall beallowed to travel directly on the GCL. Acceptable installation,for example, may be accomplished such that the GCL isunrolled in front of the backwards-moving deploymente
20、quipment, such as a front-end loader or bulldozer. If theequipment causes rutting of the subgrade, the subgrade must berestored to its originally accepted condition before placementcontinues.5.3.4 Care must be taken to minimize the extent to whichthe GCL is repositioned across the subgrade in order
21、tominimize damage to the subgrade and to the bottom surface ofthe GCL. A temporary geosynthetic subgrade covering com-monly known as a slip sheet or rub sheet may be used to reducefriction damage during placement.5.3.5 The GCL should be placed so that seams are parallelto the direction of the slope.
22、 Other industry-accepted practicesfor installing geosynthetics on slopes shall be followed whereappropriate, to help ensure that the stability and performance ofthe GCL is adequate.5.3.6 All GCL should lie flat on the underlying surface, withno wrinkles or folds, especially at the exposed edges of t
23、hepanels.5.3.7 Only as much GCL shall be deployed per working dayas can be covered in accordance with 5.8. The GCL shall becovered overnight.NOTE 2If the GCL is hydrated when no confining stress is present, itmay be necessary to remove and replace the hydrated material. The projectengineer, Construc
24、tion Quality Assurance (CQA) inspector, and GCLsupplier should be consulted for specific guidance if premature hydrationis suspected to have occurred.5.3.8 The GCL should not be installed when it is frozen.5.3.9 If GCLis placed over geosynthetic, care must be takenas to not damage underlying materia
25、l with high groundpressure equipment directly on the geosynthetic.5.4 Anchorage:5.4.1 At the top of a slope, the end of the GCL roll may beplaced in an anchor trench in accordance with the projectdrawings and specifications. The front edge of the trenchshould be rounded so as to eliminate any sharp
26、corners thatcould cause excessive stress on the GCL.5.4.2 If a trench is used for anchoring the end of the GCL,soil backfill should be placed in the trench to provide resistanceagainst pullout. The size and shape of the trench, as well as theappropriate backfill procedures, should be in accordance w
27、iththe project drawings and specifications.5.5 Seaming:5.5.1 GCL seams are constructed by overlapping theiradjacent edges. Care should be taken to ensure that the overlapzone is not contaminated with loose soil or other debris. Theoverlap may require supplemental (powdered or granular)bentonite as d
28、irected by the project specifications.Geomembrane-based GCLs also may be welded together.NOTE 3Alternate seaming methods may be approved.5.5.2 Unless otherwise specified, the minimum dimensionof the longitudinal overlap should be 150 mm. End-of-rolloverlapped seams should be constructed similarly bu
29、t theminimum overlap should measure 500 mm. Care should betaken to maintain these overlap dimensions at the time ofcovering in all climatic conditions.NOTE 4It has been documented that GCLs may have some propensityfor shrinkage if they are left under an exposed (that is, no soil cover orconfining pr
30、essure) geomembrane for months or years. Additional infor-mation related to potential shrinkage mechanisms, as well as suggestedmeasures to mitigate shrinkage, are provided in two documents from theGeosynthetic Research Institute, GRI White Paper #5 (2005)4,3andStandard Guide GRI-GCL-5 (2011). This
31、issue is not envisioned to occurfor the more common situation where soil cover is promptly placed overthe geomembrane/GCL composite liner system.5.5.3 Seams should be constructed such that they areshingled in the direction of the grade in a manner that preventsthe potential for flow entering the ove
32、rlap zone.5.6 Sealing Around Penetrations and Structures:5.6.1 Cutting the GCL should be accomplished using asharp utility knife. Frequent blade changes are recommendedto avoid damage to the synthetic components of the GCLduring the cutting process.5.6.2 The GCL shall be sealed around pipe penetrati
33、ons andstructures embedded in the subgrade using granular bentonite,powdered bentonite, or bentonite paste, in accordance with thedesign drawings or as recommended by the manufacturer.Examples of these details are presented in X1.1.5.6.3 Contact manufacturer regarding attachments to struc-tures.5.7
34、Damage RepairIf the GCL is damaged (torn,punctured, perforated, and so forth) either the entire GCL mustbe replaced or the affected area must be repaired by cutting apatch to fit above or below the damaged area. The patch shallbe obtained from a new GCL roll and shall be cut to size suchthat a minim
35、um overlap of 300 mm is achieved around all parts4Koerner, R. M., and Koerner, G. R., “In-Situ Separation of GCLPanels BeneathExposed Geomembranes,” 2005.D6102 152of the damaged area. Dry granular or powdered bentonite orbentonite paste should be applied around the damaged areaprior to placement of
36、the patch. It may be desired to use anadhesive or other approved means to affix the patch in place sothat it is not displaced during cover placement.5.8 Cover Placement:5.8.1 Cover soils shall be free of sharp-edged stones or otherforeign matter that could damage the GCL. Cover soils shouldbe an app
37、roved material with respect to particle sizeuniformity, moisture content, and chemical compatibility.NOTE 5Recommended cover soils typically have a well-gradedparticle size distribution ranging between fines and 25 mm. Soils withgreater than 50 % of material (by weight) larger than 20 mm may require
38、a field-scale test using the proposed subgrade surface, cover soil, andplacement and compaction equipment. Following construction of the testpad, the GCL should be hydrated for a minimum of 48 h and subjected tothe traffic loading necessary to simulate field conditions. The GCL thencan be exhumed an
39、d inspected for any damage to the synthetic compo-nents of the GCL and for areas of bentonite displacement.5.8.2 Soil cover shall be placed over the GCL using con-struction equipment that minimizes stresses on the GCL. Aminimum of 300 mm of cover shall be maintained between theequipment tires/tracks
40、 and the GCL at all times during thecovering process. The minimum thickness recommendationshould be increased in frequently trafficked areas or roadwaysand for high ground pressure equipment. Construction of a testpad as described in 5.8.1 is recommended for these areas.5.8.3 Soil cover should be pl
41、aced in a manner that preventsthe soil from entering the GCL overlap zones.5.8.4 A temporary cover consisting of a waterproof tarpau-lin or plastic sheet to protect GCLend-of-roll until constructionthe next day is acceptable, provided that the sheet is adequatelyballasted and that water cannot enter
42、 from the sides.5.8.5 When another geosynthetic material is placed over theGCL, care must be taken to avoid using equipment andconstruction practices that could damage the GCL.NOTE 6Although direct vehicular contact with the GCL is to beavoided, lightweight, low ground pressure vehicles (such as 4-w
43、heelall-terrain vehicles) may be used to facilitate the installation of theoverlying geosynthetic. It is recommended that a test pad be constructedon a site-specific basis to evaluate the feasibility and effect of directvehicular traffic. The project engineer should be contacted with specificrecomme
44、ndations on the appropriate procedures in this situation. A testpad need not be constructed if the project engineer determines that thereis already sufficient information available to allow the use of the directvehicular contact proposed for the project.NOTE 7When a textured geomembrane is installed
45、 over the GCL, atemporary geosynthetic covering known as a slip sheet or rub sheet maybe used to minimize friction during placement and to allow the texturedgeomembrane to be more easily moved into its final position.5.9 Hydration:5.9.1 In cases where the containment of non-aqueous liq-uids is requi
46、red, it may be necessary to hydrate the coveredGCL with fresh water prior to use. Hydration may be accom-plished (provided that the clay component of the GCL iscovered by permeable materials) by introducing water into thecontainment area, either by flooding or by the use of sprinklers.The GCL suppli
47、er should be contacted for specific proceduresif manual hydration is necessary.6. Keywords6.1 GCL; geosynthetic clay liner; installationAPPENDIX(Nonmandatory Information)X1. GCL DRAWINGSX1.1 Figs. X1.1-X1.4 depict methods that can be employedto connect a GCL to penetrations and structures. It is the
48、engineers responsibility to modify and adapt the drawing asnecessary to account for project-specific products and condi-tions. In the event of any conflict between these drawings andthe project drawings and specifications, the project-specificinformation shall supersede the information in this appen
49、dix.D6102 153FIG. X1.1 Pipe Penetration Cross-SectionD6102 154FIG. X1.2 Pipe Penetration Isometric ViewD6102 155FIG. X1.3 GCL Wall Seal-Cross SectionD6102 156ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technica
