1、Designation: D7701 11Standard Test Method forDetermining the Flow Rate of Water and Suspended Solidsfrom a Geotextile Bag1This standard is issued under the fixed designation D7701; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is used to determine the flow rate ofwater and suspended solids through a geosynthetic perm
3、eablebag used to contain high water content slurry such as dredgedmaterial.1.2 The results for the water and sediment that pass throughthe geotextile bag are shown as liters of water per time period,and the percent total suspended solids in milligrams per liter orparts per million.1.3 The flow rate
4、is the average rate of passage of a quantityof solids and water through the bag over a specific time period.1.4 This test method requires several pieces of specifiedequipment such as an integrated water sampler, analyticalbalance, geotextile container, frame to hold the geotextilecontainer, and clea
5、n containers to collect the decant water anda representative sample of high water content material from theproposed dredge area or slurry source.1.5 The values stated in SI units are to be regarded as thestandard. The values in parentheses are provided for informa-tion only.1.6 This standard does no
6、t 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.2. Referenced Documents2.1 ASTM Standard
7、s:2D123 Terminology Relating to TextilesD653 Terminology Relating to Soil, Rock, and ContainedFluidsD4354 Practice for Sampling of Geosynthetics for TestingD4439 Terminology for GeosyntheticsD4759 Practice for Determining the Specification Confor-mance of Geosynthetics3. Terminology3.1 Definitions:3
8、.1.1 For definitions of other terms relating to geosynthet-ics, refer to Terminology D44393.1.2 For definitions of textile terms, refer to TerminologyD1233.1.3 For definitions of soil terms, refer to TerminologyD6533.1.4 high water content material, n-a slurry of water andsolids exhibiting the prope
9、rties of a liquid, typically having apercent solids by weight smaller than 50% (water contentgreater than 100%), and the size of the solid particles tend to bevery fine grained (0.064 mm).3.2 Definitions of Terms Specific to This Standard:3.2.1 flow rate, nvolume of fluid per unit time, expressedas
10、an average, that passes through a geotextile hanging bag.3.2.2 geotextile hanging bag, nbag, tube, sock, or con-tainer designed and fabricated from a single or a combinationof layers of permeable geosynthetic to retain fine-grainedparticles such as found in dredged material, for subsequentdewatering
11、 of the contained semi fluid materials.4. Summary of Test Method4.1 A geotextile bag is constructed by sewing one or morelayers of geotextiles together to form a container that willsupport and contain a measured amount of saturated dredgedmaterial or other high water content material.4.1.1 The amoun
12、t of water and sediment that flows throughthe geotextile container is collected at given time intervals andmeasured. The amount of sediment passing the geotextilecontainer is determined as the total suspended solids.4.2 Use material from the designated area to be dredged atthe estimated initial perc
13、ent solids as the actual field condi-tions, or the source of the high water content material.5. Significance and Use5.1 This test method may be used as an aid to designgeotextile container systems that contain fine-grained, highwater content slurries such as dredged materials to meet specialenvironm
14、ental or operational requirements. This test is often1This 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 Oct. 1, 2011. Published October 2011. DOI: 10.1520/D
15、7701112For 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.1Copyright ASTM International, 100 Barr Harbor Drive, P
16、O Box C700, West Conshohocken, PA 19428-2959, United States.used to demonstrate the efficacy of geotextile dewatering toregulatory agencies in determining the amount of dredgedmaterial sediment passing through a geotextile and the flowrate for specific high water content materials.5.2 The designer c
17、an use this test method to assess thequantity of fine-grained dredged material sediment that maypass through the geotextile container into the environment.5.3 This test method is intended for evaluation of a specificmaterial, as the results will depend on the specific high watercontent slurry and ge
18、otextile evaluated and the location of thegeotextile container below or above water. It is recommendedthat the user or a design representative perform the test becausegeotextile manufacturers are not typically equipped to handleor test fine-grained slurries.5.4 This test method provides a means of e
19、valuating geo-textile containers with different dredged materials or highwater content materials under various conditions. The numberof times this test is repeated depends on the users and the testconditions.5.5 This test method may not simulate site conditions andthe user is cautioned to carefully
20、evaluate how the results areapplied.6. Apparatus Test A6.1 Wooden Frame, shown in Fig. 1.6.2 Geotextile Container, with eight evenly spaced metalgrommets, 1.52m (5 feet) circumference, 165-cm (65-in.),approximate capacity filled is about 75 L (40 gal), shown inFig. 2.6.3 Three shallow 8-cm (3-in.) d
21、eep, 61-cm (24-in.) diam-eter aluminum pan (hot-water heater drip pan) shown in Fig. 1.6.4 Integrated Water Sampler, a 0.5-L (0.13-gal) deviceused to collect integrated samples of water.6.5 Two large 208-L (55-gal) containers for dredged mate-rial when required.6.6 Stopwatch.6.7 Stirrer, such as a s
22、tirring rod on a portable electric drill.6.8 Dredged Material, from the proposed dredge area.6.9 Crucible.6.10 Membrane Filter Apparatus.6.11 Vacuum Pump.6.12 Sediment-Free Water, prepared from water obtainedfrom the proposed dredged area to soak geotextile containers.Do not use distilled de-ionized
23、 or water from any other source.7. Apparatus Test B7.1 Geotextile Container, with four evenly spaced fabricstraps, 0.92m (3.0 feet) deep and 1.52m (5 feet) circumferenceshown in Fig. 3.7.2 Two 15.2 cm (6 in.) deep, 41.9 cm (16.5 in.) wide and88.3cm (34.75 in.) long clear plastic pan shown in Fig. 3.
24、7.3 1000 mL graduated beaker used to collect and measuresamples of water.7.4 Stopwatch.7.5 Stirrer, such as a paint mixing rod on a portable electricdrill.FIG. 1 Procedure AD7701 1127.6 Dredged Material, from the proposed dredge area orhigh water content slurry from source, 19 Liters (5 U.S.gallons)
25、.7.7 Sediment-Free Water, prepared from water obtainedfrom the proposed dredged area to soak polyester geotextilecontainers. Do not use distilled de-ionized or water from anyother source. Since polypropylene is hydrophobic, pre-soakingis not required.8. Sampling8.1 Geotextile Container8.1.1 Lot Samp
26、le for Geotextile Container-Divide theproduct into lots and take the lot samples as directed in PracticeD4354.8.1.2 Geotextile Container SampleAfter first discarding aminimum of 1 m (3.3 ft) of geotextile from the end of the roll,cut sufficient lengths to fabricate the number of containers forthe ap
27、propriate number of tests. If holes or damaged areas areevident, then damaged areas should be discarded and addi-tional material used. No fabric should be used within 0.2 m (6in.) of a selvedge edge.8.2 Dredged Material or High Water Content MaterialObtain representative samples significant to the d
28、esign ofgeotextile containers. The size and number of samples requiredis dependent upon the number of tests to be performed.Samples should be representative of the wet bulk density, watercontent, and consistency obtained from the dredge, pump, orother source to be placed in the geotextile tube for d
29、ewatering.In some cases, this may mean adding source water to replicatefield conditions.9. Procedure9.1 Geotextile containers provided by the manufacturer areconstructed by sewing one or more geotextile layers ofgeotextile together to form a container. Test A containers shallbe 114-cm (45-in.) insid
30、e circumference and 163 cm (64 in.)long as shown in Fig. 1. A hem edge is provided along thecircumference of the container opening. Eight 1-cm (-in.)diameter metal grommets are evenly spaced about 2.5 cm (1in.) from the hem edge. Fabric seams are constructed by twodouble-lock stitches to contain the
31、 dredged material as it wouldbe in the prototype. Test B containers shall be 0.92m (3.0 feet)FIG. 2 Hanging bag for procedure AD7701 113deep and 1.52m (5 feet) circumference as shown in Fig. 4. Fourevenly spaced straps are sewn to the top finished edge. Fabric9J9 seams are constructed by two double-
32、lock stitches along thesides of the bag. There should be no seam at the bottom of thebag.9.2 When appropriate, pre-wet the geotextile container bysoaking the geotextile in prefiltered water from the proposeddredge area until fabric is fully soaked and saturated. Do notuse distilled de-ionized or wat
33、er from any other source.9.3 Attach the geotextile container to a frame or otherapparatus capable of safely holding 50 pounds, or in the case ofTestA, a sheet metal pipe with 1-cm (3/8-in.) galvanized bolts,washers, and nuts through the eight evenly spaced metalgrommets as shown inFig. 1. There shou
34、ld be a clearance ofabout 20 cm (8 in.) for the bottom of the container above thefloor of the platform to accommodate removal the collectionpans as they fill with sediment and water.9.4 After the soaked geotextile container has drained of freewater, place a dry shallow collector pan as described in
35、6.3 and7.2 under the geotextile container to collect water and sedimentby gravity flow.9.5 For Test A, obtain about 150 to 190 L (40 to 50 gal) ofthe site-specific dredged material in a 208-L(55-gal) container.Thoroughly agitate the dredged materials with the stirrer for 1min to mix in free decant w
36、ater to obtain a uniform consistencythat would be representative of dredged material after excava-tion and placement. Immediately pour this mix through anadequate size funnel attached to the geotextile container andstart the stopwatch simultaneously. For Test B, obtain approxi-mately 19 L (5 gallons
37、) of the site-specific high moisturecontent material. Thoroughly agitate as described above. Takea sample of the initial slurry for determination of percent solidsFIG. 3 Procedure BD7701 114by weight using a mud balance or by sending to a testlaboratory. Pour the mixed slurry into the hanging bag an
38、d startthe stopwatch.9.6 For TestA, as the shallow aluminum pans fill about halffull (about 11 L (3 gal) with water and sediment, remove themand record the time and quantity. Carefully place the water andsediment sample with all visible sediment in approved cleanglass containers marked with the time
39、, quantity, and order inwhich they were collected and recorded. For Test B, removethe shallow container at predetermined time intervals, imme-diately replace with a clean container, measure the volume inthe first container and record. A sample may be saved for lateranalysis. Typical time intervals w
40、ould be 2, 5, 10, 15, 30, 45,60 minutes followed by measurements at longer time intervalsup to 24 hours and a maximum of 48 hours.9.7 ForTestA, collect water and sediment from the drainageof the dredged material in the shallow aluminum pans untildrainage has slowed to less than a 2.5-cm (1-in.) dept
41、h in thepan per 24 hours. This completes the filtrate sample collectionphase of the test.9.8 At the completion of the sample collection, agitate thecollected filtrate in each container with a stirrer until themixture is uniformly mixed, After 1 min of mixing, obtain adepthintegrated suspended solids
42、 sample from the mixturewhile continuing the agitation.NOTE 1With the sampler specified in 6.4, a rate of sampling thatrequires 30 s to reach the bottom of the container and 30 s to return to thesurface is ideal. This sampling procedure allows collection of a sampleover the full depth of the mixture
43、.FIG. 4 Hanging bag for procedure BD7701 1159.9 Place a pre-weighted filter disk either on a membranefilter apparatus or in the bottom of a suitable crucible. Apply avacuum and wash the disk with three successive 20-mLportionof distilled water. Continue suction to remove all traces ofwater from the
44、disk.9.10 Carefully remove the filter disk from the membranefilter apparatus and transfer to an aluminum or stainless steelplanchet. If a crucible is used, remove the crucible and filterdisk combination.9.11 Dry the filter disk for at least1hinanoven at 104C6 1C.9.12 Store in a desiccator until cool
45、ed to room temperature.9.13 Weigh the filter disk to an accuracy of 0.000 01 g.9.14 Place the filter disk in the membrane filter apparatusand return it or the Gooch crucible to the vacuuming andfiltering apparatus.9.15 Under the vacuum, filter the sample of water collectedin 9.79.16 Repeat 9.9 throu
46、gh 9.129.17 An alternative to the method described in paragraphs8.8 through 8.16 is to take the decant water samples to a testlaboratory for determination of Total Suspended Solids andchemistry testing if required.9.18 At the end of the decant water collection period, asample of the dewatered materi
47、al retained within the geotextilebag can be obtained. Using a mud balance or other laboratorymethod, determine the final percent solids by weight of theretained material.10. Calculation10.1 Calculate total suspended solids:Ss5A2B!31000C(1)Where:Ss= suspended solids, ppm;A = weight of dry filter plus
48、 dry residue;B = weight of dry filter; andC = sample volume of suspended material, milliliters.10.2 Calculate the flow rate, FDM, of the dredged materialsediment and water for each sample collected for the geotextilecontainer using Eq 2:FDM5QPtP(2)10.2.1 Correct the flow rate to 20C using Eq 3:F20CF
49、DMUTU20C(3)Where:UT= ratio of viscosity of water at temperature T toviscosity of water at 20C (see Fig. 5).11. Report11.1 State what procedure was employed.11.2 In the report of total suspended solids and flow rate,include the following information:11.2.1 State that the specimens were tested as directed inthis test method. Describe the type of geotextile and seamtested and the sampling method used.11.2.2 Report the number of specimens tested and thedirection(s) tested (if applicable).11.2.3 Report the type of dredged material, initial volume,weight, percent soli
