1、Designation: D6072/D6072M 09 (Reapproved 2015)Standard Practice forObtaining Samples of Geosynthetic Clay Liners1This standard is issued under the fixed designation D6072/D6072M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the
2、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 practice covers procedures for sampling geosyn-thetic clay liners (GCLs) for the purpose of laboratory te
3、sting.These procedures are designed to ensure that representativesamples are obtained and properly packaged for submittal to atesting laboratory.1.2 The procedures in this practice may be applied to eithersamples of unhydrated GCLs obtained at the project site priorto installation (or at the product
4、ion facility, prior to shipment tothe project site) or samples exhumed from a project site afterinstallation.1.3 It is assumed that the number of samples to be obtainedhas already been determined in the project specification,standard test method, or by prior agreement between thepurchaser and seller
5、. This practice covers only the methods forobtaining a pre-arranged number of samples and does notdescribe methods for obtaining individual specimens from thesample.1.4 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system
6、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 therespons
7、ibility 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.2. Referenced Documents2.1 ASTM Standards:2D4220 Practices for Preserving and Transporting SoilSamplesD4354 Practice for Sampling of Geos
8、ynthetics and RolledErosion Control Products(RECPs) for TestingD4439 Terminology for GeosyntheticsD5888 Guide for Storage and Handling of GeosyntheticClay Liners3. Terminology3.1 Definitions:3.1.1 geosynthetic clay liner (GCL), na manufacturedhydraulic barrier consisting of clay bonded to a layer or
9、 layersof geosynthetics.3.1.2 sample, na portion of a material which is taken fortesting or for record purposes (See Practice D4354).3.1.3 specimen, na specific portion of a material orlaboratory sample upon which a test is performed or which istaken for that purpose (See Practice D4354).3.1.4 For d
10、efinitions of other geosynthetic terms used in thispractice, refer to Terminology D4439.4. Significance and Use4.1 This practice provides a procedure by which samples ofGCL should be obtained for laboratory testing. The practiceapplies to materials obtained prior to installation (either at a jobsite
11、 or at a production facility) or exhumed material afterinstallation.4.2 Only GCL samples obtained in accordance with 5.1 ofthis practice will be considered representative of the actualmanufactured GCL for quality assurance/quality control (QA/QC) purposes4.3 The quantity of GCL received by the labor
12、atory shouldbe sufficient for the preparation of several representative testspecimens for the standardized physical, hydraulic, and me-chanical tests to be performed on the GCLs.4.4 The procedures in this practice should be used by plantand field personnel for obtaining GCL samples for laboratorytes
13、ting.5. Procedure5.1 Obtaining Samples Prior to Installation:1This practice is under the jurisdiction of ASTM Committee D35 on Geosyn-thetics and is the direct responsibility of Subcommittee D35.04 on GeosyntheticClay Liners.Current edition approved Jan. 1, 2015. Published February 2015. Originallya
14、pproved in 1996. Last previous edition approved in 2009 as D6072/D6072M09.DOI: 10.1520/D6072_D6072M-09R15.2For 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 standa
15、rds Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.1.1 In accordance with the project specifications or withPractice D4354, divide the shipment or other given quantity ofGCL into lots, and s
16、elect lot and laboratory samples. This willusually involve the selection of a certain number of finishedGCL rolls from which samples will be cut.5.1.2 Affix on the packaging of the GCL rolls to be sampledadhesive labels or other markings which clearly identify thatthe roll is to be sampled.5.1.3 Rec
17、ord the label information from each roll to besampled for future incorporation into within the qualityassurance/quality control (QA/QC) documentation for theGCL.5.1.4 Segregate the rolls identified for sampling. Refer toGuide D5888 for the proper equipment and techniques forhandling the GCL rolls.5.
18、1.5 Inspect the packaging of the selected GCL rolls fordamage. Describe and record the damage, if any.5.1.6 Remove the outer packaging from the GCL as care-fully as possible, taking precautions not to damage the GCLand to preserve the packaging as much as possible for re-useafter sampling is complet
19、ed.5.1.7 Obtain samples from the selected GCL rolls prior todeployment. If cut on a surface, the surface on which the GCLis cut shall be dry, clean, smooth, hard and free of irregularitiesand potential contaminants.NOTE 1At the discretion of the engineer, shorter or narrower samples,or both, may be
20、obtained provided that the packaging procedures in thisguide are followed.5.1.8 A unique sample number shall be written on thesample. Additional markings should be made on the sample toidentify the machine direction and the top/bottom sides of theGCL.5.1.9 The GCL sample shall then be manually rolle
21、d arounda core at least 75 mm in diameter, in the same direction as thecut. Care should be taken to wind the GCL without slack. Widestrapping tape (50 mm) shall then be wound around the samplein at least two places to secure the loose end. Bentonite lossfrom the sample may be minimized by applying t
22、he tapearound the roll ends.5.1.10 At least two layers of plastic sheeting shall be used towrap the GCL sample roll for shipment to the laboratory, so asto minimize GCL sample disturbance or changes in moisturecontent. A thin cellophane material may be used for the innerwrapping, provided it is woun
23、d securely and repeatedly aroundthe rolled sample. The outer sheeting shall be at least 0.15 mm6 mils in thickness and shall be wrapped to minimize theamount of GCL shifting within the wrapping.5.1.11 To ensure proper sample chain-of-custody tracking,all shipping documents shall indicate the sample
24、number,project name and contact, and laboratory name and contact.5.1.12 If an additional sample from the same GCL roll isrequired for testing, 5.1.6 through 5.1.10 of this practice maybe repeated on the exposed end of the roll until a sufficientamount of GCL is obtained.NOTE 2Additional material cut
25、 from the same roll is still consideredpart of the same sample therefore should not be designated any differentlythan those samples previously obtained from the same roll.5.1.13 Samples should be transmitted to the laboratory in amanner that minimizes the amount elapsed time, samplehandling, disturb
26、ances (such as moisture, vibration, impact,etc.) that could occur in transit. Expedited delivery will help toensure that moisture content changes are minimized.NOTE 3These packaging procedures were developed under theassumption that the area from which specimens are obtained is at least75 mm from th
27、e edges of the sample.5.2 Exhuming Samples After Installation:5.2.1 There are two methods for exhuming GCL samples.Method A is the suggested method for multi-component GCLsor GCLs covered with a geomembrane. Method B is thesuggested method when there is no multi-component GCL noris the GCL covered w
28、ith a geomembrane, although Method Acan be used in cases where larger samples are required.5.2.2 Method AHand Cutting method:5.2.2.1 Using a small backhoe or other piece of constructionequipment carefully excavate a hole at the desired locationdown to within hand shoveling distance of approximately1
29、50 mm 6 in. of the GCL. Once cover removal begins,machinery should not be placed in the area to be exhumed. Tominimize stress on GCL, within 150 mm 6 in. the GCL, theoverlying soil should be removed by hand and any overlyinggeosynthetics shall be cut by hand. Measure the depth of thecover soil, as w
30、ell, the inclination and direction of inclination;for example, south, east, west, north.NOTE 4Once the overlying soil is removed, evaporation of water inthe GCL may occur. Consequently, the GCL should be removed no morethan 30 min from the time the overlying soil is removed. When a GCL isoverlain by
31、 a geomembrane, the geomembrane should remain in placeuntil the GCL is to be sampled. If heating of the geomembrane by solarradiation is a concern during this period, a white fabric or white plasticsheet should be draped over the geomembrane to reflect solar radiation.5.2.2.2 The sample area shall b
32、e large enough such thatspecimens subsequently cut from the removed sample in thelaboratory for testing are no closer than 75 mm from any edge.The sample also must not be cut too close to the side of theexcavation so that the geomembrane and GCL may be repairedor patched as recommended by the manufa
33、cturers.5.2.2.3 If the GCL is overlain with a geomembrane, first thegeomembrane shall be cut over an area larger than thesubsequent GCL sample area and removed prior to cutting theGCL. GCL samples shall be cut with a sharp utility knife orother implement capable of making a clean, straight cutthroug
34、h all the components of the GCL.5.2.2.4 The sample width and length dimensions shall bemeasured and recorded.5.2.2.5 To minimize the potential for bending or distortingthe GCL, the sample shall be kept flat at all times duringremoval and placed upon a nonporous rigid plate. This can beaccomplished b
35、y cutting a notch into the subgrade adjacent tothe GCL, placing the rigid plat into the notch adjacent to theGCL sample and either sliding the GCL onto the plate orsliding the plate below the GCL (see Fig. 1).5.2.2.6 To minimize changes in moisture content, at leasttwo layers of plastic sheeting sha
36、ll be used to wrap the GCLsample and plate for shipment to the laboratory, A thincellophane material may be used for the inner wrapping,D6072/D6072M 09 (2015)2provided the cellophane is wound securely and repeatedlyaround the sample and plate. The outer sheeting shall be at least0.1 mm 4 mils in thi
37、ckness and shall be wrapped tight enoughto minimize the amount of GCL shifting within the wrapping.5.2.2.7 Unique sample identification shall be marked on thewrapped sample.5.2.2.8 If requested and practical, a confining pressure canbe applied upon the GCL sample. This can be accomplishedeither by p
38、lacing a second rigid plate over the GCL prior towrapping and then placing dead weights over the sample, or byplacing the sample in a container and then carefully placing asufficient amount of soil over the sample.5.2.2.9 Sample soils immediately adjacent to the GCL perPractices D4220.5.2.2.10 If re
39、quired, repair and/or patch the geosynthetics inthe excavation as recommended by the manufacturers andbackfill the entire excavation according to the protocol agreedto by the parties involved.5.2.2.11 To ensure proper sample chain-of-custody tracking,all shipping documents shall indicate the sample
40、number,project name and contact, and laboratory name and contact.5.2.2.12 Samples should be transmitted to the laboratory ina manner that minimizes the amount of elapsed time, samplehandling, disturbances (such as moisture loss, distortion,impact, etc.) that could occur in transit. Expedited deliver
41、y willhelp to ensure that moisture content changes are minimized.5.2.2.13 Samples should be stored and handled by thelaboratory in a manner that minimizes the amount of elapsedtime, sample handling, disturbances (such as moisture loss,distortion, impact, etc.) that could occur prior to testing.5.2.3
42、 Method BCoring method:5.2.3.1 Using a small backhoe or other piece of constructionequipment carefully excavate a hole at the desired locationdown to within hand shoveling distance of approximately15 cm 6 in. of the GCL. Carefully remove the remaining soilby hand to within 25 mm 1 in. of the top of
43、the GCL.5.2.3.2 Advance a hand auger with a 150 mm 6 in.diameter, end-sharpened thin-wall sampling tube (see Fig.2(a) into the cover soil to the top of the GCL.NOTE 5ParAide Turf Mender Model #1004 with ParAide Tube BladeModel #1010 has been found satisfactory for this purpose.5.2.3.3 After advancin
44、g the auger to the surface of the GCL,a utility knife should be used to pre-cut the GCL around the150 mm 6 in. diameter inner perimeter of the tube. Thenadvance the auger through the pre-cut GCL and approximately25 mm 1 in. beneath the GCL.FIG. 1 (a) Digging Notch in Subgrade Adjacent to Sample Cove
45、red by Rigid Plate (b) Rigid Plate Placed into Notch Adjacent to GCLSample. (c) GCL sample on Rigid Plate.FIG. 2 (a) Auger and Sampling Tube Next to Spare Sampling TubeTurned on its Side (b) Composite (Soil/GCL/Soil) Sample Ex-tracted from Sampling Tube.D6072/D6072M 09 (2015)35.2.3.4 Withdraw the sa
46、mpler from the soil formation ascarefully as possible in order to minimize disturbance of thesample. The tube can be slowly rotated to shear the material atthe end of the tube, and to relieve water or suction pressures,or both, and improve recovery. Retrieve the auger with itssoil/GCL/soil sample. R
47、emove the thin-wall sampling tube atthe end of the auger, and immediately seal both sample endsassuring that the sample has no way of moving about in thetube.NOTE 6If soil is lost and not flush with either end of the tube, thenspacers or appropriate packing materials should be inserted prior toseali
48、ng the tube end(s) to provide proper confining pressure. Packingmaterials must be nonabsorbent and must maintain their properties toprovide the same degree of sample support with time.5.2.3.5 Unique sample identification shall be marked on theassembly, as well as, field orientation (that is, top, bo
49、ttom).5.2.3.6 If repair of the excavation area is required, firstcarefully fill and compact the hole up to the level of the GCLwith soil. Then patch the sampled GCL hole with a patch ofsimilar GCL that is at least 0.3 m 12 in. beyond the edges ofthe sampled hole placing 0.4 kg/m 0.25 lb/linear foot ofbentonite between the patch and the GCL. Carefully backfillthe entire excavation according to the protocol agreed to by theparties involved.5.2.3.7 To ensure proper sample chain-of-custody tracking,all shipping documents shall indicate the sample numbe
