Standard Test Method for Hydraulic Conductivity of Essentially Saturated Peat

SIGNIFICANCE AND USE
Values of hydraulic conductivity determined by this test method may be useful in making rough preliminary estimates of the initial rates of drainage and compression of peat deposits when the only effective stress increase on the deposit is that resulting from a moderate, gradual lowering of the water table.
Even under light, sustained loads, peat will undergo dramatic volume changes that influence (decrease) the hydraulic conductivity of the deposit by several orders of magnitude. This test method does not offer provisions for the determination of the relationship between hydraulic conductivity and the void ratios corresponding to increasing stress levels. Therefore, this test method is not suitable for applications involving grade increases, such as embankment construction or placement of access berms alongside drainage ditches.
Undisturbed specimens from apparently homogeneous peat deposits at the same location often exhibit significantly different hydraulic conductivity properties due to variations in material composition and sampling procedure.
Note 1—The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D 3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D 3740 does not in itself ensure reliable results. Reliable results depend on many factors; Practice D 3740 provides a means of evaluating some of those factors.
SCOPE
1.1 This test method covers the determination of the hydraulic conductivity (permeability) of essentially saturated, intact cylindrical specimens of peat when the hydraulic conductivity is greater than 1 10-7 m/s (1 10-5 cm/s). During the test, the specimens are contained in the core holder, or in right, regular cylindrical sections cut from the sampling tube in which they were originally obtained in the field.
1.2 Hydraulic conductivity is calculated on the basis of the measured constant flow rate through the specimen under constant head. For verification, flow rate determinations may be made at two or more values of constant head with corresponding calculations of hydraulic conductivity.
1.3 The values stated in SI units are to be regarded as the standard.
1.4 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026.
1.4.1 The procedures used to specify how data are collected/recorded and calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that should generally be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user's objectives, and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analysis methods for engineering design.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

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ASTM D4511-00(2006) - Standard Test Method for Hydraulic Conductivity of Essentially Saturated Peat
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D4511–00 (Reapproved 2006)
Standard Test Method for
Hydraulic Conductivity of Essentially Saturated Peat
This standard is issued under the fixed designation D4511; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* 2. Referenced Documents
1.1 This test method covers the determination of the hy- 2.1 ASTM Standards:
draulic conductivity (permeability) of essentially saturated, D653 Terminology Relating to Soil, Rock, and Contained
intact cylindrical specimens of peat when the hydraulic con- Fluids
−7 −5
ductivityisgreaterthan1 310 m/s(1 310 cm/s).During D1587 PracticeforThin-WalledTubeSamplingofSoilsfor
the test, the specimens are contained in the core holder, or in Geotechnical Purposes
right,regularcylindricalsectionscutfromthesamplingtubein D2434 Test Method for Permeability of Granular Soils
which they were originally obtained in the field. (Constant Head)
1.2 Hydraulic conductivity is calculated on the basis of the D2974 TestMethodsforMoisture,Ash,andOrganicMatter
measured constant flow rate through the specimen under of Peat and Other Organic Soils
constant head. For verification, flow rate determinations may D3740 Practice for Minimum Requirements for Agencies
be made at two or more values of constant head with Engaged in Testing and/or Inspection of Soil and Rock as
corresponding calculations of hydraulic conductivity. Used in Engineering Design and Construction
1.3 The values stated in SI units are to be regarded as the D4220 Practices for Preserving and Transporting Soil
standard. Samples
1.4 All observed and calculated values shall conform to the D4753 Guide for Evaluating, Selecting, and Specifying
guideforsignificantdigitsandroundingestablishedinPractice Balances and Standard Masses for Use in Soil, Rock, and
D6026. Construction Materials Testing
1.4.1 Theproceduresusedtospecifyhowdataarecollected/ D6026 PracticeforUsingSignificantDigitsinGeotechnical
recorded and calculated in this standard are regarded as the Data
industry standard. In addition, they are representative of the 2.2 NRC Document:
significant digits that should generally be retained. The proce- Peat Testing Manual
dures used do not consider material variation, purpose for
3. Terminology
obtaining the data, special purpose studies, or any consider-
ations for the user’s objectives, and it is common practice to 3.1 Definitions—For common definitions of terms in this
standard, refer to Terminology D653.
increase or reduce significant digits of reported data to be
commensuratewiththeseconsiderations.Itisbeyondthescope 3.2 Definitions of Terms Specific to This Standard:
3.2.1 deaerated (de-aired) water—water in which the
of this standard to consider significant digits used in analysis
methods for engineering design. amount of dissolved gas (air) has been reduced.
3.2.2 flow rate—the quantity of water flowing through the
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the test specimen in a given period of time, when subjected to a
certain constant head differential.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 3.2.3 soaking—placement of a specimen in water for the
purpose of removing gas contained in the pore space, through
bility of regulatory limitations prior to use.
bouyancy, and replacement with water to cause saturation of
the specimen. This method of saturation does not effectively
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
Rock and is the direct responsibility of Subcommittee D18.04 on Hydrologic
Properties of Soil and Rock.
Current edition approved Feb. 1, 2006. Published March 2006. Originally For referenced ASTM standards, visit the ASTM website, www.astm.org, or
approved in 1992. Last previous edition approved in 2000 as D4511–00. DOI: contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
10.1520/D4511-00R06. Standards volume information, refer to the standard’s Document Summary page on
Forfurtherinformation,see“MethodsforMeasurementofSaturatedHydraulic the ASTM website.
Conductivity,” Peat Testing Manual, Technical Memorandum No. 125, NRC National Research Council of Canada, Publications Section, Building R–88,
Canada, pp. 80–84. Ottawa, Canada K1A 0R6. Out of print.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4511–00 (2006)
remove all the gas contained in the specimen and does not 6.1.4 Direct proportionality of flow velocity with hydraulic
prevent the continuous slow formation of gas from decompo- gradients below certain values, after which flow becomes
sition under anaerobic conditions. turbulent.
6.2 All other types of flow involving partial saturation of
4. Significance and Use
void space, turbulent flow, and unsteady state of flow are
4.1 Values of hydraulic conductivity determined by this test
transient in character and yield variable and time-dependent
method may be useful in making rough preliminary estimates
valuesofhydraulicconductivity;therefore,theyrequirespecial
oftheinitialratesofdrainageandcompressionofpeatdeposits
test conditions and procedures.
when the only effective stress increase on the deposit is that
resultingfromamoderate,gradualloweringofthewatertable.
7. Apparatus
4.2 Even under light, sustained loads, peat will undergo
7.1 Flow Device—TheflowdeviceshallbeasshowninFig.
dramatic volume changes that influence (decrease) the hydrau-
1, fitted with the following components:
lic conductivity of the deposit by several orders of magnitude.
7.1.1 Constant-Head Filter Tank, as shown in Fig. 1 ofTest
This test method does not offer provisions for the determina-
Method D2434, to supply water and to remove most of the air
tionoftherelationshipbetweenhydraulicconductivityandthe
from the water. The tank shall be fitted with a suitable siphon.
voidratioscorrespondingtoincreasingstresslevels.Therefore,
NOTE 2—Alternatively, deaerated water may be used, supplied from a
thistestmethodisnotsuitableforapplicationsinvolvinggrade
self-siphoning burette with attached inverted flask (minimum 750-mL
increases, such as embankment construction or placement of
capacity), filled with deaerated water, and closed with a rubber stopper
access berms alongside drainage ditches.
holding a tube, 150 cm (6 in.) long with the end cut diagonally.
4.3 Undisturbed specimens from apparently homogeneous
7.1.2 Upper Reservoir, of the same diameter as the sam-
peat deposits at the same location often exhibit significantly
pling cylinder and approximately 150 cm (6 in.) high.
different hydraulic conductivity properties due to variations in
7.1.3 Wire-Screen Support, fabricated from a ring clamp,
material composition and sampling procedure.
with an inside diameter greater than the specimen cylinder and
NOTE 1—The quality of the result produced by this standard is
covered with 425-µm (No. 40) wire mesh screening.
dependent on the competence of the personnel performing it, and the
7.1.4 Circular Disk, cut from 425-µm (No. 40) wire mesh
suitability of the equipment and facilities used. Agencies that meet the
screening, with a diameter 1 mmm smaller than that of the
criteria of Practice D3740 are generally considered capable of competent
specimen.
and objective testing/sampling/inspection/etc. Users of this standard are
7.1.5 Funnel, with a head diameter at least 10% larger than
cautioned that compliance with Practice D3740 does not in itself ensure
reliable results. Reliable results depend on many factors; Practice D3740 that of the specimen cylinder.
provides a means of evaluating some of those factors.
7.1.6 Two 400-mL Beakers.
7.2 Balance—Abalanceorscaleconformingtotherequire-
5. Interferences
ments of Specification D4753, readable (with no estimate) to
5.1 Due to the generally fibrous texture and extremely high
0.1% of the test mass, or better.
compressibilityofpeat,presentsamplingtechnologiesmaynot
7.3 Miscellaneous Apparatus and Materials, such as ther-
be able to obtain samples truly representative of the in situ
mometers, timer reading to nearest second, soaking pan, pipe
conditions. Disturbance caused by sampling and specimen
cutters, trimming knife, cheese cloth, rubber bands, vinyl
preparation as well as heterogeneity existing in situ may cause
electrical tape, and micro-crystalline wax.
the hydraulic conductivity determined using this method to be
significantly different than the in situ hydraulic conductivity.
8. Specimen Preparation and Set Up
5.2 There are no provisions in this test method for verifica-
8.1 Specimens shall have a minimum diameter of 73 mm
tion of compliance with the fundamental test conditions listed
(2.87 in.). The height-to-diameter ratio shall be between 1 and
in 6.1.1 and 6.1.2. The assumption is made that these condi-
2.
tions are satisfied if the flow rate, with time, is a linear
8.2 Prepare specimens from tube samples secured in accor-
relationship.
dance with Practice D1587, or other acceptable undisturbed
5.3 Theresultofthetestmaybeinfluencedbyflowthrough
sampling procedure, yielding cylindrical samples obtained in
open passages between the specimen and the rigid wall of the
tight-fitting, rigid-metal core holders (Note 3). Preserve and
specimencontainer.Ifsuchaconditionissuspectedorvisually
transport the specimens in accordance with the practice for
verified, notice thereof should be made in the test report.
Group D samples in Practices D4220 (Note 4).
6. Fundamental Test Conditions
NOTE 3—Samples of fibrous peat from shallow depths can be secured
6.1 The following ideal test conditions are prerequisite for with the least amount of disturbance using a rotary type sampling device
equipped with a thin cutting edge, serrated with saw-teeth.
laminar flow of water through porous media under constant-
NOTE 4—The integrity of a sample contained in a sampler liner or core
head conditions:
holderisbestpreservedifthesampleendsaretrimmedflushwiththeends
6.1.1 Continuity of flow with no volume change during a
of the liner and capped using tight-fitting, rigid-metal end caps, securely
test,
taped in place and dipped in micro-crystalline wax.
6.1.2 Flow with the void space saturated with water and no
air bubbles in the voids,
6.1.3 Flow in the steady state with no changes in hydraulic
S
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