1、Designation: D5856 95 (Reapproved 2007)D5856 15Standard Test Method forMeasurement of Hydraulic Conductivity of Porous MaterialUsing a Rigid-Wall, Compaction-Mold Permeameter1This standard is issued under the fixed designation D5856; the number immediately following the designation indicates the yea
2、r oforiginal adoption or, in the case of revision, the 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 covers laboratory measurement of the h
3、ydraulic conductivity (also referred to as coeffcient of permeability)of laboratory-compacted materials with a rigid-wall, compaction-mold permeameter.1.2 This test method may be used with laboratory-compacted specimens that have a hydraulic conductivity less than or equalto 1 105 m/s. The hydraulic
4、 conductivity of compacted materials that have hydraulic conductivities greater than 1 105 m/smay be determined by Test Method D2434.1.3 UnitsThe values stated in SI units are to be regarded as the standard, unless other units are specifically given. By traditionin U.S. practice, hydraulic conductiv
5、ity is reported in centimetres per second, cm/s, although the common SI units for hydraulicconductivity are metres per second.m/s.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establi
6、sh appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and Contained FluidsD698 Test Methods for Laboratory Compaction Characteristics of Soil Using Standard
7、Effort (12 400 ft-lbf/ft3 (600 kN-m/m3)D854 Test Methods for Specific Gravity of Soil Solids by Water PycnometerD1557 Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3 (2,700kN-m/m3)D2216 Test Methods for Laboratory Determination of Water (Moistu
8、re) Content of Soil and Rock by MassD2434 Test Method for Permeability of Granular Soils (Constant Head) (Withdrawn 2015)3D3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used inEngineering Design and ConstructionD4753 Guide for Evaluating
9、, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and ConstructionMaterials TestingD5084 Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible WallPermeameterE145 Specification for Gravity-Convection and Forced-Ventilation
10、 Ovens3. Terminology3.1 Definitions of Terms Specific to This Standard:Definitions:3.1.1 fluxquantity of flow per unit area per unit time.3.1.1 hydraulic conductivity, kthe rate of discharge of water under laminar flow conditions through a unit cross-sectional areaof a porous medium under a unit hyd
11、raulic gradient and standard temperature conditions (20C).1 This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.04 on Hydrologic Propertiesand Hydraulic Barriers.Current edition approved May 1, 2007June 1, 2015. Publi
12、shed July 2007July 2015. Originally approved in 1995. Last previous edition approved in 20022007 asD585695(2002)D585695(2007).e1. DOI: 10.1520/D5856-95R07.10.1520/D5856-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Ann
13、ual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an i
14、ndication of what changes have been made to the previous version. Becauseit 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 versionof the standard as published by ASTM is to b
15、e considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.1.1 DiscussionThe term coeffcient of permeability is often used instead of hydraulic conductivity ,conductivity, but hydraulic conductivity is used
16、exclusively in this test method. A more complete discussion of the terminology associated with Darcys law is given in theliterature4.3.1.3 pore volume of flowthe cumulative quantity of outflow from a test specimen divided by the volume of pore space in thespecimen.3.1.2 For common definitions of oth
17、ertechnical terms used in this test method seestandard, refer to Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 fluxquantity of flow per unit area per unit time.3.2.2 pore volume of flowthe cumulative quantity of outflow from a test specimen divided by the volume of pore s
18、pace in thespecimen.4. Significance and Use4.1 This test method applies to one-dimensional, laminar flow of water within laboratory-compacted, porous materials such assoil.4.2 The hydraulic conductivity of porous materials generally decreases with an increasing amount of air in the pores of themater
19、ial. This test method applies to porous materials containing little or no air. The test method is designed to minimize theamount of air in the test specimen. However, this test method does not ensure complete saturation of the test specimen with water.In cases where it is essential to saturate the t
20、est specimen fully with water, the compacted specimen may be tested using TestMethod D5084.4.3 This test method applies to permeation of porous materials with water. Permeation with other liquids, such as chemicalwastes, can be accomplished using procedures similar to those described in this test me
21、thod. However, this test method is onlyintended to be used when water is the permeant liquid.4.4 It is assumed that Darcys law is valid and that the hydraulic conductivity is essentially unaffected by hydraulic gradient.The validity of DarcysDarcys law may be evaluated by measuring the hydraulic con
22、ductivity of the specimen at three hydraulicgradients; if all measured values are similar (within 25 %), then DarcysDarcys law may be taken as valid. However, when thehydraulic gradient acting on a test specimen is changed, the state of stress will also change, and, if the specimen or pore fluid isc
23、ompressible, the volume of the test specimen or pore fluid will change. Thus, some change in hydraulic conductivity may occurwhen the hydraulic gradient is altered, even in cases where DarcysDarcys law is valid.4.5 One potential problem with this method of testing is the possibility that water will
24、flow along the interface between the testspecimen and the compaction/permeameter ring. The problem tends to be of minimal significance for materials that swell whenexposed to water (for example, compacted, clayey soils) but can be a very serious problem for materials that might tend to shrinkand pul
25、l away from the walls of the permeameter. Test Method D5084 is recommended for any material that tends to shrink whenexposed to the permeant liquid.4.6 The correlation between results obtained with this test method and the hydraulic conductivities of in-place, compactedmaterials has not been fully i
26、nvestigated. Experience has sometimes shown that flow patterns in small, laboratory-prepared testspecimens do not necessarily follow the same patterns on large field scales and that hydraulic conductivities measured on smalltest specimens are not necessarily the same as larger-scale values. Therefor
27、e, the results should be applied to field situations withcaution and by qualified personnel.NOTE 1The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of theequipment and facilities used. Agencies that meet the criteri
28、a of Practice D3740 are generally considered capable of competent and objectivetesting/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself ensure reliable results.Reliable results depend on many factors; Practice D3740 provides a means
29、 of evaluating some of those factors.5. Apparatus5.1 Hydraulic SystemConstant head (Test Method A), falling head (Test Methods B, C, and D), or constant rate of flow (TestMethod E) systems may be used provided they meet the criteria outlined as follows:5.1.1 Constant HeadThe system must be capable o
30、f maintaining a constant hydraulic pressure or head to within 6 5 % 65 %and shall include means to measure hydraulic pressures or heads to within the prescribed tolerance. In addition, the head loss acrossthe test specimen must be held constant to within 6 5 % 65 % and shall be measured with the sam
31、e accuracy or better. Pressuresshall be measured by a pressure gage,gauge, electronic pressure transducer, or any other device of suitable accuracy. Head of liquidin a standpipe may be measured with a graduated pipette,pipet, ruler, scale, or other device of suitable accuracy.4 Olson, R. E., and Dan
32、iel, D. E., “Measurement of the Hydraulic Conductivity of Fine-Grained Soils,” Symposium on Permeability and Groundwater ContaminantTransport, ASTM STP 746, ASTM, 1981, pp. 1864.D5856 1525.1.2 Falling HeadThe system shall allow for measurement of the applied head loss, thus hydraulic gradient, to wi
33、thin65 %within 65 % or better at any time. In addition, the ratio of initial head loss divided by final head loss over an interval of timeshall be measured such that this computed ratio is accurate to within65 %.65 %.The head loss shall be measured with a pressuregage,gauge, electronic pressure tran
34、sducer, engineersengineers scale, graduated pipette,pipet, or any other device of suitableaccuracy. Falling head tests may be performed with either a constant tailwater elevation (Test Method B), rising tailwater elevation(Test Method C), or increasing tailwater elevation (Test Method D).5.1.3 Const
35、ant Rate of FlowThe system must be capable of maintaining a constant rate of flow through the specimen to within6 5 % 65 % or better. Flow measurement or control shall be by calibrated syringe, graduated pipette,pipet, or other device ofsuitable accuracy. The head loss across the specimen shall be m
36、easured to an accuracy of65 %65 % or better using an electronicpressure transducer or other device of suitable accuracy.Ameans to ensure that the head being measured is not affected by sidewallleakage should be included. More information on testing with a constant rate of flow is given in the litera
37、ture5.5.2 Flow Measurement SystemBoth inflow and outflow volumes shall be measured or controlled. Flow volumes shall bemeasured by a graduated accumulator, graduated pipette,pipet, graduated cylinder, vertical standpipe in conjunction with anelectronic pressure transducer, marriotte bottle, or other
38、 volume-measuring device of suitable accuracy. For long-term tests,evaporative losses may be significant and should be accounted for using a suitable correction procedure.5.2.1 Flow AccuracyRequired accuracy for the quantity of flow measured over an interval of time is 6 5 % 65 % or better.5.2.2 Hea
39、d LossesHead losses in the tubes, valves, porous end pieces, and filter paper may lead to error. To guard against sucherrors, the permeameter shall be assembled with no specimen inside (but with any porous end pieces or sheets of filter paper thatwill be used) and then the hydraulic system filled. I
40、f a constant or falling head test is to be used, the hydraulic pressures or headsthat will be used in testing a specimen shall be applied, and the rate of flow measured with an accuracy of 6 5 % 65 % or better.This rate of flow shall be at least ten times greater than the rate of flow that is measur
41、ed when a specimen has been compactedinside the permeameter and the same hydraulic pressures or heads are applied. If a constant rate of flow test is to be used, the rateof flow to be used in testing a specimen shall be supplied to the permeameter and the head loss measured. The head loss withouta s
42、pecimen shall be less than 0.1 times the head loss when a specimen is present.5.3 Permeameter CellThe permeameter cell shall consist of a rigid-wall compaction mold into which the material to be testedis compacted and in which the compacted material is permeated; and two end plates to control flow i
43、nto and out of the testspecimen. A swell ring may be provided as discussed in 5.3.2. The permeameter shall be designed and operated so that permeantwater flows downward through the test specimen, although upward flow may be used if the top of the specimen is protected fromupward movement by a rigid
44、porous element.5.3.1 Compaction Mold/Permeameter RingThe compaction mold/permeameter ring shall be constructed of a rigid materialthat will not be damaged during compaction of the test specimen and that will not undergo adverse chemical reactions with thetest material or permeant water. Materials su
45、ch as steel, aluminum, brass, plastic, and glass have been used. The mold shall besufficiently rigid so that its expansion when the permeameter is pressurized is negligibly small. The mold can be any cylindricalshape so long as: the cross-sectional area along the direction of flow does not vary by m
46、ore than62 %;62 %; height and diameterare each 25 25 mm; height does not vary by more than 6 1 %, 61 %, and the largest particle and clod size in the compactedspecimen is 16 the lesser of the height or diameter.5.3.2 Swell RingThe top of the permeameter may be designed to function in one of three wa
47、ys: (1) to allow no restraint againstswelling (see Fig. 1), in which case a swell ring separates the compaction mold/permeameter ring from the top plate; (2) to allowno swelling of the test specimen (see Fig. 2), in which case no swell ring is provided; or (3) to control the vertical stress that isa
48、pplied to the test specimen (see Fig. 3), in which case a swell ring may or may not be needed, depending upon how the top plateis designed and how the vertical stress is applied. If a swell ring is used, it shall be constructed of a rigid material that will notreact adversely with the test material
49、or permeant water, shall have the same diameter or width as the compactionmold/permeameter ring, and shall be sufficiently high to allow free swelling of the test specimen or to accommodate stress-controlapparatus. Sand may be placed in the swell ring to minimize erosion of the specimen from influent flow provided that the sandis included in the measurement of head losses in the permeameter (see 5.2.2).5.3.3 Stress-Control ApparatusIf the upper surface of the compacted test specimen is subjected to a controlled vertical stress,the stre
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