1、Designation:D610206D610212 Standard Guide for Installation of Geosynthetic Clay Liners 1 This standard is issued under the xed designation D6102; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision.Anumber in
2、 parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval. 1. Scope 1.1 This guide covers directions for the installation of geosynthetic clay liners (GCLs) under eld conditions typically present in environmental l
3、ining applications. 1.2 This guide contains general installation guidelines. It is not intended to replace project-specic installation requirements as found in the contract drawings or specications. In the event of a conict, the requirement of the project specications will supersede the requirements
4、 of this guide. 1.3 This guide does not purport to establish specic procedure for all climatic, geographical, hydraulic, or topographical conditions that may exist at a site. Appropriate installation procedures under atypical eld conditions should be modied as necessary to maintain the integrity of
5、the GCL and adjacent lining system components. 1.4 Different GCLs have different materials of construction with different physical properties.The procedures contained in this guide, therefore, may not be universally applicable to all GCLs under all eld conditions. 1.5 This standard does not purport
6、to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. Referenced Documents 2.1 ASTM Standards: 2 D65
7、3Terminology Relating to Soil, Rock, and Contained Fluids D4439Terminology for Geosynthetics D5888Guide for Storage and Handling of Geosynthetic Clay Liners 3. Terminology 3.1 DenitionsFor denitions of other geosynthetic terms used in this guide, refer to Terminology D4439. For denitions of soils te
8、rms, refer to Terminology D653. 3.1 Denitions of Terms Specic to This Standard:Denitions: 3.2.1 geosynthetic clay liner (GCL), na manufactured hydraulic barrier consisting of clay bonded to a layer or layers of geosynthetics.For denitions of other geosynthetic terms used in this guide, refer to Term
9、inology D4439. For denitions of soils terms, refer to Terminology D653. 3.2 3.3 geosynthetic clay liner (GCL), na manufactured hydraulic barrier consisting of clay bonded to a layer or layers of geosynthetics. 4. Signicance and Use 4.1 Foroptimumperformance,GCLsmustbeinstalledinamannerthatdoesnotimp
10、acttheirphysical,mechanical,orhydraulic properties. 4.2 This guide identies the proper installation procedures and equipment for use by GCLdesigners, inspectors, and installers. 1 This guide is under the jurisdiction ofASTM Committee D35 on Geosynthetics and is the direct responsibility of Subcommit
11、tee D35.04 on Geosynthetic Clay Liners. Current edition approved Jan. 1, 2006July 1, 2012. Published February 2006August 20126. Originally approved in 1997. Last previous edition approved in 20042006 as D610204.06. DOI: 10.1520/D6102-06.10.1520/D6102-12. 2 ForreferencedASTMstandards,visittheASTMwebs
12、ite,www.astm.org,orcontactASTMCustomerServiceatserviceastm.org.For Annual Book ofASTM Standards volume information, refer to the standards Document Summary page on the ASTM website. This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what
13、 changes have been made to the previous version. Because it may not be technically possible to adequately depict all changes accurately,ASTM recommends that users consult prior editions as appropriate. In all cases only the current version of the standard as published by ASTM is to be considered the
14、 official document. Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States 15. Procedure 5.1 ThemethodsandequipmentusedforplacementoftheGCLcanvary,buttheprimaryobjectiveoftheprocessistominimize the potential for GCL damage. The placement met
15、hods and equipment should be evaluated appropriately within this context. 5.2 Subgrade Preparation: 5.2.1 ForprojectswheretheGCListobeplacedoveranearthensubgrade,thesubgradesurfacemustbepreparedandapproved prior to installation in accordance either with project specications or with this guide.The su
16、rface should be rm and unyielding, with no abrupt elevation changes, voids and cracks, ice, or standing water. 5.2.2 The subgrade surface should be smooth and free of vegetation, sharp-edged rocks, stones, sticks, construction debris, and other foreign matter that could contact the GCL. The subgrade
17、 surface shall be compacted in accordance with the project specications. At a minimum, the subgrade should be rolled with a smooth-drum compactor of sufficient weight to remove any excessivewheelruts,footprints,orotherabruptgradechanges.Excessiveruttingshouldbeclearlydenedandquantied.Insome cases 25
18、 mm is the maximum rut depth allowed. Furthermore, all protrusions extending more than 12 mm from the subgrade surface shall either be removed, crushed, or pushed into the surface with a smooth-drum compactor. 5.3 GCL Placement: 5.3.1 All handling of the GCL at the job site should be conducted in ac
19、cordance with Guide D5888. 5.3.2 GCLrollsaretobedeliveredtotheworkingareaofthesiteintheiroriginalpackaging.Immediatelypriortodeployment, the packaging shall be carefully removed without damaging the GCL. NOTE 1The orientation of the GCL (that is, which side faces up) may be important and shall be in
20、 accordance with the engineers requirements. 5.3.3 No equipment that could damage the GCL shall be allowed to travel directly on the GCL. Acceptable installation, for example, may be accomplished such that the GCL is unrolled in front of the backwards-moving deployment equipment, such as a front-end
21、 loader or bulldozer. If the equipment causes rutting of the subgrade, the subgrade must be restored to its originally accepted condition before placement continues. 5.3.4 Care must be taken to minimize the extent to which the GCL is repositioned across the subgrade in order to minimize damage to th
22、e subgrade and to the bottom surface of the GCL.Atemporary geosynthetic subgrade covering commonly known as a slip sheet or rub sheet may be used to reduce friction damage during placement. 5.3.5 The GCL should be placed so that seams are parallel to the direction of the slope. Other industry-accept
23、ed practices for installinggeosyntheticsonslopesshallbefollowedwhereappropriate,tohelpensurethatthestabilityandperformanceoftheGCL is adequate. 5.3.6 AllGCLshouldlieatontheunderlyingsurface,withnowrinklesorfolds,especiallyattheexposededgesofthepanels. 5.3.7 Only as much GCL shall be deployed per wor
24、king day as can be covered in accordance with 5.8. The GCL shall be covered overnight. NOTE 2If the GCL is hydrated when no conning stress is present, it may be necessary to remove and replace the hydrated material. The project engineer, Construction Quality Assurance (CQA) inspector, and GCL suppli
25、er should be consulted for specic guidance if premature hydration is suspected to have occurred. 5.3.8 The GCL should not be installed when it is frozen. 5.3.9 If GCL is placed over geosynthetic, care must be taken as to not damage underlying material with high ground pressure equipment directly on
26、the geosynthetic. 5.4 Anchorage: 5.4.1 At the top of a slope, the end of the GCLroll may be placed in an anchor trench in accordance with the project drawings and specications.The front edge of the trench should be rounded so as to eliminate any sharp corners that could cause excessive stress on the
27、 GCL. 5.4.2 If a trench is used for anchoring the end of the GCL, soil backll should be placed in the trench to provide resistance against pullout. The size and shape of the trench, as well as the appropriate backll procedures, should be in accordance with the project drawings and specications. 5.5
28、Seaming: 5.5.1 GCL seams are constructed by overlapping their adjacent edges. Care should be taken to ensure that the overlap zone is not contaminated with loose soil or other debris. The overlap may require supplemental (powdered or granular) bentonite as directed by the project specications. Geome
29、mbrane-based GCLs also may be welded together. NOTE 3Alternate seaming methods may be approved. 5.5.2 Unlessotherwisespecied,theminimumdimensionofthelongitudinaloverlapshouldbe150mm.End-of-rolloverlapped seams should be constructed similarly but the minimum overlap should measure 500 mm. Care should
30、 be taken to maintain these overlap dimensions at the time of covering in all climatic conditions. NOTE4IthasbeendocumentedthatGCLsmayhavesomepropensityforshrinkageiftheyareleftunderanexposed(thatis,nosoilcoverorconning pressure)geomembraneformonthsoryears.Additionalinformationrelatedtopotentialshri
31、nkagemechanisms,aswellassuggestedmeasurestomitigate shrinkage,areprovidedintwodocumentsfromtheGeosyntheticResearchInstitute,GRIWhitePaper#5(2005)andStandardGuideGRI-GCL-5(2011). D610212 2This issue is not envisioned to occur for the more common situation where soil cover is promptly placed over the
32、geomembrane/GCL composite liner system. 5.5.3 Seams should be constructed such that they are shingled in the direction of the grade in a manner that prevents the potential for ow entering the overlap zone. 5.6 Sealing Around Penetrations and Structures: 5.6.1 Cutting the GCL should be accomplished u
33、sing a sharp utility knife. Frequent blade changes are recommended to avoid damage to the synthetic components of the GCL during the cutting process. 5.6.2 TheGCLshallbesealedaroundpipepenetrationsandstructuresembeddedinthesubgradeinaccordancewiththedesign drawings or as recommended by the manufactu
34、rer. Examples of these details are presented in X1.1. 5.6.3 Contact manufacturer regarding attachments to structures. 5.7 Damage RepairIf the GCLis damaged (torn, punctured, perforated, and so forth) either the entire GCLmust be replaced or the affected area must be repaired by cutting a patch to t
35、above or below the damaged area. The patch shall be obtained from anewGCLrollandshallbecuttosizesuchthataminimumoverlapof300mmisachievedaroundallpartsofthedamagedarea. Dry bentonite or bentonite mastic should be applied around the damaged area prior to placement of the patch. It may be desired to us
36、e an adhesive or other approved means to affix the patch in place so that it is not displaced during cover placement. 5.8 Cover Placement: 5.8.1 Cover soils shall be free of sharp-edged stones or other foreign matter that could damage the GCL. Cover soils should be an approved material with respect
37、to particle size uniformity, moisture content, and chemical compatibility. NOTE 5Recommended cover soils typically have a well-graded particle size distribution ranging between nes and 25 mm. Soils with greater than 50% of material (by weight) larger than 20 mm may require a eld-scale test using the
38、 proposed subgrade surface, cover soil, and placement and compaction equipment. Following construction of the test pad, the GCL should be hydrated for a minimum of 48 h and subjected to the traffic loading necessary to simulate eld conditions. The GCL then can be exhumed and inspected for any damage
39、 to the synthetic components of the GCL and for areas of bentonite displacement. 5.8.2 Soil cover shall be placed over the GCL using construction equipment that minimizes stresses on the GCL.Aminimum of 300 mm of cover shall be maintained between the equipment tires/tracks and the GCLat all times du
40、ring the covering process. The minimum thickness recommendation should be increased in frequently trafficked areas or roadways and for high ground pressure equipment. Construction of a test pad as described in 5.8.1 is recommended for these areas. 5.8.3 Soil cover should be placed in a manner that p
41、revents the soil from entering the GCL overlap zones. 5.8.4 Atemporary cover consisting of a waterproof tarpaulin or plastic sheet to protect GCL end-of-roll until construction the next day is acceptable, provided that the sheet is adequately ballasted and that water cannot enter from the sides. 5.8
42、.5 WhenanothergeosyntheticmaterialisplacedovertheGCL,caremustbetakentoavoidusingequipmentandconstruction practices that could damage the GCL. NOTE 6Although direct vehicular contact with the GCL is to be avoided, lightweight, low ground pressure vehicles (such as 4-wheel all-terrain vehicles)maybeus
43、edtofacilitatetheinstallationoftheoverlyinggeosynthetic.Theprojectengineershouldbecontactedwithspecicrecommendations on the appropriate procedures in this situation. NOTE 7When a textured geomembrane is installed over the GCL, a temporary geosynthetic covering known as a slip sheet or rub sheet may
44、be used to minimize friction during placement and to allow the textured geomembrane to be more easily moved into its nal position. 5.9 Hydration: 5.9.1 In cases where the containment of non-aqueous liquids is required, it may be necessary to hydrate the covered GCLwith water prior to use. Hydration
45、may be accomplished (provided that the clay component of the GCL is covered by permeable materials) by introducing water into the containment area, either by ooding or by the use of sprinklers.The GCLsupplier should be contacted for specic procedures if manual hydration is necessary. 6. Keywords 6.1
46、 geosynthetic clay liner; GCL; installation D610212 3APPENDIX (Nonmandatory Information) X1. GCL Drawings X1.1 Figs. X1.1-X1.4 depict methods that can be employed to connect a GCLto penetrations and structures. It is the engineers responsibility to modify and adapt the drawing as necessary to accoun
47、t for project-specic products and conditions. In the event ofanyconictbetweenthesedrawingsandtheprojectdrawingsandspecications,theproject-specicinformationshallsupersede the information in this appendix. FIG. X1.1Pipe Penetration Cross-Section D610212 4FIG. X1.2Pipe Penetration Isometric View D61021
48、2 5FIG. X1.3GCL Wall Seal-Cross Section D610212 6ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any such patent right
49、s, and the risk of infringement of such rights, are entirely their own responsibility. Thisstandardissubjecttorevisionatanytimebytheresponsibletechnicalcommitteeandmustbereviewedeveryveyearsand ifnotrevised,eitherreapprovedorwithdrawn.Yourcommentsareinvitedeitherforrevisionofthisstandardorforadditionalstandards and should be addressed toASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. If you feel that your comment
