1、Designation: D 5101 01 (Reapproved 2006)Standard Test Method forMeasuring the Soil-Geotextile System Clogging Potential bythe Gradient Ratio1This standard is issued under the fixed designation D 5101; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a performance test applicablefor determining the soil-geotextil
3、e system permeability andclogging behavior for cohesionless soils under unidirectionalflow conditions.1.2 The values stated in SI units are to be regarded asstandard. The values in parentheses are for information only.1.3 This standard does not purport to address all of thesafety concerns, if any, a
4、ssociated 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 Standards:2D 123 Terminology Relating to TextilesD 653 Terminolog
5、y Relating to Soil, Rock, and ContainedFluidsD 737 Test Method for Air Permeability of Textile FabricsD 4354 Practice for Sampling of Geosynthetics for TestingD 4439 Terminology for Geosynthetics3. Terminology3.1 Definitions:3.1.1 clogging potential, nin geotextiles, the tendency fora given fabric t
6、o lose permeability due to soil particles thathave either lodged in the fabric openings or have built up arestrictive layer on the surface of the fabric.3.1.2 geotextile, na permeable geosynthetic comprisedsolely of textiles.3.1.3 gradient ratio, nin geotextiles, the ratio of thehydraulic gradient t
7、hrough a soil-geotextile system to thehydraulic gradient through the soil alone.3.1.4 hydraulic gradient, i, s (D)the loss of hydraulichead per unit distance of flow, dH/dL.3.1.5 For definitions of other textile terms, refer to Termi-nology D 123. For definitions of other terms related to geotex-til
8、es, refer to Terminology D 4439 and Terminology D 653.3.2 Symbols and Acronyms:3.2.1 CO2the chemical formula for carbon dioxide gas.3.2.2 CHDthe acronym for constant head device.4. Summary of Test Method4.1 This test method requires setting up a cylindrical, clearplastic permeameter (see Fig. 1 and
9、Fig. 2) with a geotextileand soil, and passing water through this system by applyingvarious differential heads. Measurements of differential headsand flow rates are taken at different time intervals to determinehydraulic gradients. The following test procedure describesequipment needed, the testing
10、procedures, and calculations.5. Significance and Use5.1 This test method is recommended for evaluating theperformance of various soil-geotextile systems under con-trolled test conditions. Gradient ratio values obtained may beplotted and used as an indication of the soil-geotextile systemclogging pot
11、ential and permeability. This test method is notappropriate for initial comparison or acceptance testing ofvarious geotextiles. The test method is intended to evaluategeotextile performance with specific on-site soils. It is im-proper to utilize the test results for job specifications ormanufacturer
12、s certifications.5.2 It is important to note the changes in gradient ratiovalues with time versus the different system hydraulic gradi-ents, and the changes in the rate of flow through the system(see Section 11 and Annex A1.).6. Apparatus and Supplies6.1 Soil-Geotextile Permeameter(three-piece unit)
13、equipped with support stand, soil-geotextile support screen,piping barriers (caulk), clamping brackets, and plastic tubing(see Fig. 2). Both 100-mm (4-in.) and 150-mm (6-in.) diameterpermeameters are described.6.2 Two Constant Water Head Devices, one mounted on ajack stand (adjustable) and one stati
14、onary (Fig. 3).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 June 1, 2006. Published June 2006. Originallyapproved in 1990. Last previous edition appro
15、ved in 2001 as D 5101 01.2For 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 standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 B
16、arr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.3 Soil Leveling Device (Fig. 4).6.4 Manometer Board, of parallel glass tubes and measuringrulers.6.5 Two Soil Support Screens, of approximately 5 mm(No. 4) mesh.6.6 Soil Support Cloth, of 150 m (No. 100) mesh, orequival
17、ent geotextile.6.7 Thermometer (0 to 50 6 1C).6.8 Graduated Cylinder, 100 6 1cm3capacity.6.9 Stopwatch.6.10 Balance, or scale of at least 2-kg capacity and accurateto 61g.6.11 Carbon Dioxide, (CO2), gas supply and regulator.6.12 Geotextile.6.13 Water Recirculation System.6.14 Water Deairing System,
18、with a capacity of approxi-mately 1700 L/day (500 gal/day).6.15 Algae Inhibitor, or micro screen.6.16 150-m Mesh Screen, (No. 100), or equivalent geo-textile for manometer ports.6.17 Soil Sample Splitter (optional).6.18 Pan, for drying soil.6.19 Mortar and Pestle, for pulverizing soil.6.20 Wooden ro
19、d, 20-mm (34 in.) diameter by 150 mm(6 in.) long.7. Sampling and Test Specimens7.1 Lot Sample and Laboratory SampleTake a lot sampleand laboratory samples as directed in Practice D 4354. Forlaboratory samples, take a full width swatch of geotextile fromeach roll of material in the lot sample at leas
20、t1m(3ft)longcut from the end of the roll after discarding the first metre ofmaterial from the outside of the roll.7.2 Test SpecimenCut one circular specimen from eachswatch in the laboratory sample with the specimen having adiameter of 110 mm (4.33 in.) or 165 mm (6.50 in.). Take thespecimen from th
21、e center of the swatch.8. Conditioning8.1 Test Water Preparation:8.1.1 Test water should be maintained at room temperatureabout 16 to 27C (60 to 80F), and deaired to a dissolvedoxygen content of 6 ppm or less before introducing it topermeameter system. This will reduce or eliminate the prob-lems ass
22、ociated with air bubbles forming within the testapparatus.8.1.2 An algae inhibitor or micro screen should be used toeliminate any algae buildup in the system.8.2 Specimen Conditions:8.2.1 Condition the specimen by soaking it in a container ofdeaired water for a period of 2 h. Dry the surface of thes
23、pecimen by blotting prior to inserting in the permeameter.9. Procedure9.1 Preparation of Apparatus:9.1.1 Thoroughly clean and dry permeameter sections.9.1.2 Close all valves and cover the inside openings of allmanometer ports with fine wire mesh or lightweight nonwovenfabric (the equivalent of No. 1
24、00 mesh).9.1.3 Lubricate all O-ring gaskets.9.2 Permeameter Preassembly:9.2.1 Stand center section of the permeameter on end andplace a soil support cloth 110 mm (4.33 in.) or 165 mm (6.5 in.)in diameter on recessed permeameter flanges.9.2.2 Insert the support screen 110 mm (4.33 in.) or 165 mm(6.5
25、in.) in diameter on top of the support cloth with the meshside against the cloth.9.2.3 Align and insert top section of the permeameter intocenter section and press until there is a tight fit to secure thesupport cloth and screen in place. Ensure that all gasket edgessecure against the support cloth,
26、 support bracket, and betweenthe center and top permeameter sections.9.2.4 Invert and place permeameter into holding stand.9.3 Process Soil:The test is to be performed on 10 mm (38 in.) material.The material passing the 10 mm (38 in.) and retained on the No.10 sieve is subject to a second round of g
27、rinding to ensure thatthe sample has been broken down into individual grains.9.3.1 Thoroughly air dry the soil sample as received fromthe field.This shall be done for a minimum of three days. Grindthe sample in a mortar with a rubber-tipped pestle (or in someFIG. 1 Geotextile PermeameterD 5101 01 (2
28、006)2other way that does not cause breakdown of individual grains),to reduce the particle size to a maximum of 10 mm (38 in.).Select a representative sample of the amount required, approxi-mately 1350 g (or 3000 g for the 150-mm (6-in.) diameter), toperform the test by the method of quartering or by
29、 the use ofa soil splitter.9.3.2 Select that portion of the air-dried sample selected forpurpose of tests and record the mass as the mass of the total testsample uncorrected for hygroscopic moisture. Separate the testsample by sieving with a 2-mm (No. 10) sieve. Grind thatfraction retained on the 2-
30、mm (No. 10) sieve in a mortar witha rubber-covered pestle until the aggregations of soil particlesare broken up into the separate grains.9.3.3 Mix the fractions passing the 2-mm (No. 10) sievealong with the portion that was retained on the 2-mm (No. 10)sieve to form the test soil. All particles larg
31、er than 10 mm (38in.) should be eliminated.9.4 Soil PlacementThe following procedures offer twooptions to the user. The first is a “standard” placement whilethe second is a “field condition” placement. The placementprocedure is a critical aspect of the test and may significantlyinfluence the test re
32、sults.9.4.1 Standard Placement Method:9.4.1.1 Weigh out approximately 1350 g of airdried pro-cessed soil (or 3000 g for the 150-mm (6-in.) diameter).9.4.1.2 Place air-dried processed soil above the supportcloth to a depth of 103 mm (4.12 in.). The final depth of soilafter settlement will be approxim
33、ately 100 mm (4 in.). The soilshould be placed in 25-mm (1-in.) to 40-mm (112-in.) layers,making sure that no voids exist along the permeameter walls atmanometer ports, or the caulk piping barriers. The soil shall beplaced carefully into the permeameter with a scoop or appro-priate tool with a maxim
34、um drop of the soil no greater than25 mm (1 in.). Consolidation of each layer shall consist ofFIG. 2 SectionGeotextile PermeameterD 5101 01 (2006)3tapping the side of the permeameter six times with a woodenrod, 20 mm (34 in.) by 150 mm (6 in.) in diameter.9.4.1.3 When the level of the soil in the pe
35、rmeameterreaches a depth of 100 mm (4 in.), insert the soil levelingdevice (Fig. 4), with the notch down, on the top edges of thepermeameter. Continue placing soil and rotating the levelingdevice until the total soil height of 103 mm (4.12 in.) isreached.9.4.1.4 Remove the soil leveler and any exces
36、s soil. Deter-mine the mass of the soil in the permeameter for unit weightcalculations.NOTE 1The standard soil placement procedure results in a relativelyloose soil condition and is conservative for many applications. If a densityapproximating actual field soil conditions is desirable, the field con
37、ditionprocedure should be used. It should be recognized, however, thatpredicting field soil conditions may be very difficult due to constructioninstallation procedures that generally disturb and loosen soils adjacent tothe geotextile.9.4.2 Field Condition Soil Placement Method:9.4.2.1 Based on the d
38、esired field dry density, weigh out theprocessed dry soil required to achieve the target dry density inthe permeameter used with a 100 mm (4 in.) soil height.9.4.2.2 Place the dry soil in four one-inch lifts using the endof the wooden dowel to compact the soil, making sure that novoids exist along t
39、he permeameter walls at the manometerports or the caulk piping barriers.9.4.2.3 Fill the permeameter to achieve the soil height of100 mm (4 in.). Determine the mass of soil used for unit weightcalculations.NOTE 2Should the target density be unachievable without increasingthe compaction effort, recor
40、d the density actually achieved. While thelooser condition may be somewhat more conservative, the dry placementand CO2purge are considered critical to reliable results.9.5 Permeameter Assembly and Setup:9.5.1 Clean the inner flange of the center section of thepermeameter and insert the geotextile to
41、 be tested.9.5.2 Insert the support screen on top of the geotextile withthe mesh side against the geotextile.9.5.3 Align and insert the bottom section of the permeame-ter into the center section and press tightly to secure thegeotextile and support screen. The soil will compress from103 mm (4.12 in.
42、) to approximately 100 mm (4 in.) when thebottom section is secured. Check gaskets to ensure contact ismade between permeameter sections, support screen, andgeotextile.9.5.4 Secure the permeameter sections together withinclamp brackets and tighten bolts on bracket rods evenly.9.5.5 Invert permeamete
43、r into holding stand so that thegeotextile will be below the soil level.9.5.6 Connect the inflow and outflow constant head devices(CHD) to their corresponding permeameter ports (see Fig. 3)with plastic tubing. The outflow CHD is attached to the bottompermeameter port and the inflow CHD is attached t
44、o the toppermeameter port.9.5.7 Connect all manometer tubes (1 through 5) to theircorresponding permeameter manometer ports, and all overflowtubes to their corresponding outlet ports.9.6 Saturating the Soil/Geotextile System:FIG. 3 Geotextile Permeameter “Set Up” DiagramD 5101 01 (2006)49.6.1 Open t
45、he top vent valve, and close off the permeame-ter water outlet hose.9.6.2 Backfill permeameter with water through the outflowCHD until the water level is approximately 10 mm (38 in.)below the open manometer port 6. Stop waterflow into thepermeameter by clamping off the hose between outflow CHDand pe
46、rmeameter.9.6.3 Expel oxygen and other gases in the permeameter andsoil system by (1) attaching a carbon dioxide (CO2) line tomanometer port 6, and (2) regulating the gas flow at 2 L/minand purging the system for 5 min.9.6.4 After 5 min of gas saturation, seal off (plug) the openend of each manomete
47、r tube (1 through 5) and continue topurge the system with CO2for an additional 5 min with onlythe top vent valve open.9.6.5 Remove the CO2gas line and replace the No. 6manometer hose. Remove the seals (plugs or clamps) from allmanometer tubes (1 through 5).9.6.6 Loosen the hose clamp between the out
48、flow CHD andpermeameter, and fill the soil section of the permeameter withwater. Filling is accomplished by adding water to and raisingthe level on outflow CHD slowly. Start with outflow CHD at 25mm (1 in.) above the geotextile level and raise 25 mm (1 in.)every 30 min until water level is 50 mm (2
49、in.) above the topsupport screen bracket. This slow saturating process is neces-sary to prevent air pockets or internal soil movement duringloading.9.6.7 Clamp the hose between outflow CHD and permeame-ter to prevent flow. Continue to raise the water level in thepermeameter by filling from the top inlet through the inflowCHD. The outflow CHD should be clamped so that no flowoccurs through the system. The water level should be raiseduntil water flows from the top vent valve. Position outflowCHD so that its overflow outlet is approximately 25 mm (1 i
