1、Designation: D7880/D7880M 13Standard Test Method forDetermining Flow Rate of Water and Suspended SolidsRetention from a Closed Geosynthetic Bag1This standard is issued under the fixed designation ; the number immediately following the designation indicates the year of originaladoption or, in the cas
2、e of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () 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 geos
3、ynthetic permeableclosed bag used to contain high water content slurry such asdredged material.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 millio
4、n.1.3 The flow rate 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 bag, stand clear PVC pipes, testing fr
5、ame,and clean containers to collect the decant water and a repre-sentative sample of high water content material from theproposed dredge area or slurry source.1.5 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may no
6、t be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibilit
7、y 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:2D123 Terminology Relating to TextilesD653 Terminology Relating to Soil, Rock, and ContainedFluidsD43
8、54 Practice for Sampling of Geosynthetics and RolledErosion Control Products(RECPs) for TestingD4439 Terminology for Geosynthetics3. Terminology3.1 Definitions:3.1.1 For definitions of other terms relating togeosynthetics, refer to Terminology D4439.3.1.2 For definitions of textile terms, refer to T
9、erminologyD123.3.1.3 For definitions of soil terms, refer to TerminologyD653.3.1.4 high water content material, na slurry of water andsolids exhibiting the properties of a liquid, typically having apercent solids by weight smaller than 50 % (water contentgreater than 100 %), and the size of the soli
10、d particles tend tobe very 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 an average, that passes through a geotextile hanging bag.3.2.2 geotextile hanging bag, nbag, tube, sock, or con-tainer designed and fabri
11、cated from a single or a combinationof layers of permeable geosynthetic to retain finegrainedparticles such as found in dredged material, for subsequentdewatering of the contained semi fluid materials.4. Summary of Test Method4.1 A geotextile bag is constructed by sewing one or morelayers of geotext
12、iles together to form a closed container with anentry clear PVC pipe providing entry to the bag. The bag willsupport and contain a measured amount of saturated dredgedmaterial or other high water content material.4.2 The amount of water and sediment that flows throughthe geotextile container is coll
13、ected at given time intervals andmeasured. The amount of sediment passing the geotextilecontainer is determined as the total suspended solids.4.3 Use material from the designated area to be dredged atthe estimated initial percent solids as the actual fieldconditions, or the source of the high water
14、content material.1This 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 July 1, 2013. Published July 2013. DOI: 10.1520/D7880_D7880M132For referenced ASTM stand
15、ards, 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
16、 19428-2959. United States15. 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 specialenvironmental or operational requirements. This test is oftenused to demon
17、strate 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 can use this test method to assess thequantity of fine-grained dredged mat
18、erial 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 geotextile evaluated and the location of thegeotextile container below or a
19、bove 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 evaluating geo-textile containers with different dredged materials or high
20、water 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 evaluate how the results areapplied.6. Apparatus6.1 Frame. Shown in Fig.
21、1.6.2 Geosynthetic Bag (container), unfilled bag dimensionsshall be approximately 53 cm 21 in. length approximately53 cm 21 in. width to produce a filled bag capacity of 1 ft3.Bag shall have all the sides sawed using the same stitch patternand seam along the entire edge.6.2.1 The Geosynthetic Bag (c
22、ontainer) shall have a 50.8mm 2.0 in. diameter female adaptor coarse threaded PVCflange installed at the top side of the bag. The center of theFIG. 1 Test Equipment, Bag and FrameD7880/D7880M 132adapter should be located at the center of the two transversalaxis of the bag. Shown in Fig. 1.6.3 Collec
23、tion Container approximate capacity filled about75 L 20 gal, suitable to capture filtrate and proportionatelysized to allow placement under the testing frame. Shown inFig. 1.6.4 “Stand” Pipe made from 50.8 mm 2.0 in. diameter andat least 1.10 m 43.30 in. in length clear PVC or other suitableplastic.
24、 “Stand” Pipe shall include a threaded male adapter tofacilitate connection the female PVC flange.6.5 Funnel.6.6 IntegratedWater Sampler, a 0.5-L0.13-gal device usedto collect integrated samples of water.6.7 Stopwatch.6.8 Stirrer, such as a stirring rod on a portable electric drill.6.9 Dredged Mater
25、ial, from the proposed dredge area.6.10 Gooch Crucible.6.11 Membrane Filter Apparatus.6.12 Vacuum Pump.7. Sampling7.1 Geotextile Container:7.1.1 Lot Sample for Geotextile ContainerDivide theproduct into lots and take the lot samples as directed in PracticeD4354.7.1.2 Geotextile Container SampleAfter
26、 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 appropriate number of tests. If holes or damaged areas areevident, then damaged areas should be discarded and addi-tional material used. No fabric shoul
27、d be used within 0.2 m 6in. of a selvedge edge.7.2 Dredged Material or High Water Content MaterialObtain representative samples significant to the design ofgeotextile containers. The size and number of samples requiredis dependent upon the number of tests to be performed.Samples should be representa
28、tive of the wet bulk density, watercontent, and consistency obtained from the dredge, pump, orother source to be placed in the geotextile tube for dewatering.In some cases, this may mean adding source water to replicatefield conditions.8. Procedure8.1 When appropriate, pre-wet the geotextile contain
29、er bysoaking the geotextile in prefiltered water from the proposeddredge area until fabric is fully soaked and saturated. Do notuse distilled de-ionized or water from any other source.8.2 Place the geotextile container on top of the framecapable of safely holding 50 lb. There should be a clearance o
30、fabout 20 cm 8 in. for the bottom of the container above thefloor of the platform to accommodate removal of the collectionpans as they fill with sediment and water. Insert and secure theclear stand pipe in the threaded adaptor.8.3 After the soaked geotextile container has drained of freewater, place
31、 a dry shallow collector pan as described in 6.3under the geotextile container to collect water and sediment bygravity flow.8.4 Collect approximately 55 to 95 L 15 to 25 gal ofsludge into a suitable container and mix to ensure uniformity.NOTE 1Alarger sample of sludge may be required if a low percen
32、tageof solids is present.8.5 Assemble the testing frame if necessary and place asuitable collection container or under the frame to catch theeffluent during testing.8.6 Fill the geosynthetic bag by pouring the sludge into thetop of the “stand” pipe. A smaller bucket and funnel can beutilized to faci
33、litate this process. The “stand” pipe should belifted off of the bottom of the geosynthetic bag; otherwise, theintroduced sludge may back up in the pipe and overflow. Thisshould no longer be of concern once the test bag has accumu-lated some volume of sludge.8.7 Fill the geosynthetic bag with sludge
34、 as rapidly aspossible until the sludge rises in the “stand” pipe to apre-determined height corresponding to an agreed head pres-sure.8.8 Collect effluent samples from the bag. The effluentshould be examined for clarity and samples may be taken fortesting.8.9 If samples are to be collected for testi
35、ng, carefully placethe water sample with all visible sediment in approved cleanglass containers marked with the time, quantity, and order inwhich they were collected and recorded.Astopwatch should beutilized to determine the elapsed time that each sample wascollected.8.10 Empty the collection contai
36、ner and collect the waterand sediment for sampling in approved clean glass containersmarked with the time, quantity, and order in which they werecollected and recorded.8.11 Continue to collect the water and sediment for sam-pling from the collection container for about one week or untildrainage has
37、slowed to less than a 25.4-mm 1-in. depth in thecontainer per 24 h. This completes the filtrate sample collectionphase of the test.8.12 At the completion of the sample collection, agitate thecollected filtrate in each of the glass containers with a stirreruntil the mixture is uniformly mixed, After
38、1 min of mixing,obtain a depth-integrated suspended solids sample from themixture while continuing the agitation.NOTE 2With the sampler specified in 6.3, 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 allow
39、s collection of a sampleover the full depth of the mixture.8.13 Place a pre-weighted filter disk either on a membranefilter apparatus or in the bottom of a suitable Gooch crucible.Apply a vacuum and wash the disk with three successive20-mL portion of distilled water. Continue suction to removeall tr
40、aces of water from the disk.D7880/D7880M 1338.14 Carefully remove the filter disk from the membranefilter apparatus and transfer to an aluminum or stainless steelplanchet. If a Gooch crucible is used, remove the crucible andfilter disk combination.8.15 Dry the filter disk for at least1hinanoven at 1
41、04C6 1C.8.16 Store in a desiccator until cooled to room temperature.9. Calculation9.1 Calculate total suspended solids:Ss 5(A 2 B) 31000C(1)where:Ss= suspended solids, ppm;A = weight of dry filter plus dry residue;B = weight of dry filter; andC = sample volume of suspended material, millilitres.9.2
42、Calculate the flow rate, FDM, of the dredged materialsediment and water for each sample collected for the geotextilecontainer using Eq 2:FDM5QPtp(2)where:QP= quantity of dredged material sediment and water col-lected in the aluminum pans for each sample.tp= time is measured in minutes for each sampl
43、e collected.9.2.1 Correct the flow rate to 20C using Eq 3:F20C5FDMUTU20C(3)where:UT= ratio of viscosity of water at temperature T to viscosityof water at 20C (see Fig. 2).10. Report10.1 In the report of total suspended solids and flow rate,include the following information:10.1.1 State that the spec
44、imens were tested as directed inthis test method. Describe the type of geotextile and seamtested and the sampling method used.FIG. 2 Flow Rate to 20CD7880/D7880M 13410.1.2 Report the number of specimens tested and thedirection(s) tested (if applicable).10.1.3 Report the type of dredged material, ini
45、tial volume,weight, and height of material used and any data showingpertinent physical properties of the dredged material soil.10.1.4 Report mass of sediment collected in pan.10.1.5 Report complete test data including temperature ofthe water, recorded flow rates, length of test, and suspendedsolids
46、content for each dredged material and water samplecollected and total average values for all tests.10.1.6 Give a statement of any deviation from the describedtest method.11. Precision and Bias11.1 PrecisionThe precision of the procedure in this testmethod for measuring suspended solids and flow rate
47、s forgeotextile containers for dredged material containment systemswill be established within five years.11.2 BiasThe procedure in this test method for measuringsuspended solids and flow rate of a geotextile container systemmay be biased because of different geotextile containergeometries, container
48、 surface area, container volume, type ofdredged material, or whether the container is submerged or notsubmerged. The test method described is simply an index testto determine the relative difference in flow rate and suspendedsolids with the use of various geotextile systems and varioustypes of dredg
49、ed materials. The sediments determined forsubmerged containers would be much less than for non-submerged containers because the pressure gradient and flowrate is very small for submerged containers and is caused onlyby the slow release of pore water pressure during sedimenta-tion and consolidation of the dredged material.12. Keywords12.1 contaminated dredged materials; dredged materials;flow rates; geotextile containers; suspended solidsASTM International takes no position respecting the validity of any patent rights asserted in connecti
