ASTM D5093-02(2008)
(Test Method)Standard Test Method for Field Measurement of Infiltration Rate Using Double-Ring Infiltrometer with Sealed-Inner Ring
Standard Test Method for Field Measurement of Infiltration Rate Using Double-Ring Infiltrometer with Sealed-Inner Ring
SIGNIFICANCE AND USE
This test method provides a means to measure low infiltration rates associated with fine-grained, clayey soils, and are in the range of 1 × 10−7 m/s to 1 × 10−9 m/s.
This test method is particularly useful for measuring liquid flow through soil moisture barriers such as compacted clay liner or covers used at waste disposal facilities, for canal and reservoir liners, for seepage blankets, and for amended soil liners such as those used for retention ponds or storage tanks.
The purpose of the sealed inner ring is to: (1) provide a means to measure the actual amount of flow rather than a drop in water elevation which is the flow measurement procedure used in Test Method D 3385 and (2) to eliminate evaporation losses.
The purpose of the outer ring is to promote one-dimensional, vertical flow beneath the inner ring. The use of large diameter rings and large depths of embedments helps to ensure that flow is essentially one-dimensional.
This test method provides a means to measure infiltration rate over a relatively large area of soil. Tests on large volumes of soil can be more representative than tests on small volumes of soil.
The data obtained from this test method are most useful when the soil layer being tested has a uniform distribution of pore space, and when the density and degree of saturation and the hydraulic conductivity of the material underlying the soil layer are known.
Changes in water temperature can introduce significant error in the volume change measurements. Temperature changes will cause water to flow in or out of the inner ring due to expansion or contraction of the inner ring and the water contained within the inner ring.
The problem of temperature changes can be minimized by insulating the rings, by allowing enough flow to occur so that the amount of flow resulting from a temperature change is not significant compared to that due to infiltration, or by connecting and disconnecting the bag from the inner ring when the water in the inner...
SCOPE
1.1 This test method describes a procedure for measuring the infiltration rate of water through in-place soils using a double-ring infiltrometer with a sealed inner ring.
1.2 This test method is useful for soils with infiltration rates in the range of 1 × 10−7 m/s to 1 × 10−10 m/s. When infiltration rates ≥1 × 10−7 m/s are to be measured Test Method D 3385 shall be used.
1.3 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice D 6026.
1.3.1 The method used to specify how data are collected, calculated, or recorded in this standard is not directly related to the accuracy to which the data can be applied in design or other uses, or both. How one applies the results obtained using this standard is beyond its scope.
1.4 This test method provides a direct measurement of infiltration rate, not hydraulic conductivity. Although the units of infiltration rate and hydraulic conductivity are similar, there is a distinct difference between these two quantities. They cannot be directly related unless the hydraulic boundary conditions, such as hydraulic gradient and the extent of lateral flow of water are known or can be reliably estimated.
1.5 This test method can be used for natural soil deposits, recompacted soil layers, and amended soils such as soil bentonite and soil lime mixtures.
1.6 The values stated in SI units are to be regarded as standard. The values in parentheses are for information only.
1.7 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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Designation:D5093 −02(Reapproved 2008)
Standard Test Method for
Field Measurement of Infiltration Rate Using Double-Ring
Infiltrometer with Sealed-Inner Ring
This standard is issued under the fixed designation D5093; 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
2.1 ASTM Standards:
1.1 This test method describes a procedure for measuring
the infiltration rate of water through in-place soils using a D653Terminology Relating to Soil, Rock, and Contained
Fluids
double-ring infiltrometer with a sealed inner ring.
D3385Test Method for Infiltration Rate of Soils in Field
1.2 Thistestmethodisusefulforsoilswithinfiltrationrates
Using Double-Ring Infiltrometer
−7 −10
intherangeof1×10 m/sto1×10 m/s.Wheninfiltration
−7 D3740Practice for Minimum Requirements for Agencies
rates ≥1×10 m/s are to be measured Test Method D3385
Engaged in Testing and/or Inspection of Soil and Rock as
shall be used.
Used in Engineering Design and Construction
1.3 All observed and calculated values shall conform to the
D6026Practice for Using Significant Digits in Geotechnical
guideforsignificantdigitsandroundingestablishedinPractice
Data
D6026.
3. Terminology
1.3.1 The method used to specify how data are collected,
calculated,orrecordedinthisstandardisnotdirectlyrelatedto
3.1 Definitions:
theaccuracytowhichthedatacanbeappliedindesignorother
3.1.1 infiltration—downward entry of liquid into a porous
uses, or both. How one applies the results obtained using this
body.
standard is beyond its scope.
3.1.2 infiltration rate, I—quantity of liquid entering a po-
3 2
1.4 This test method provides a direct measurement of
rous material (m ) per unit area (m ) per unit time (s),
infiltration rate, not hydraulic conductivity.Although the units
expressed in units of m/s.
of infiltration rate and hydraulic conductivity are similar, there
3.1.3 infiltrometer—a device used to pond liquid on a
is a distinct difference between these two quantities. They
porous body and to allow for the measurement of the rate at
cannot be directly related unless the hydraulic boundary
which liquid enters the porous body.
conditions, such as hydraulic gradient and the extent of lateral
3.1.4 Fordefinitionsofothertermsusedinthistestmethod,
flow of water are known or can be reliably estimated.
see Terminology D653.
1.5 This test method can be used for natural soil deposits,
recompacted soil layers, and amended soils such as soil
4. Summary of Test Method
bentonite and soil lime mixtures.
4.1 The infiltration rate of water through soil is measured
1.6 The values stated in SI units are to be regarded as
usingadouble-ringinfiltrometerwithasealedorcoveredinner
standard. The values in parentheses are for information only.
ring (Fig. 1). The infiltrometer consists of an open outer and a
sealed inner ring. The rings are embedded and sealed in
1.7 This standard does not purport to address all of the
trenches excavated in the soil. Both rings are filled with water
safety concerns, if any, associated with its use. It is the
such that the inner ring is submerged.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4.2 The rate of flow is measured by connecting a flexible
bility of regulatory limitations prior to use.
bag filled with a known weight of water to a port on the inner
ring.Aswaterinfiltratesintothegroundfromtheinnerring,an
equal amount of water flows into the inner ring from the
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland
Rock and is the direct responsibility of Subcommittee D18.04 on Hydrologic
Properties and Hydraulic Barriers. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Sept. 1, 2008. Published September 2008. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1990. Last previous edition approved in 2002 as D5093–02. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D5093-02R08. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5093−02 (2008)
5.8 The problem of temperature changes can be minimized
by insulating the rings, by allowing enough flow to occur so
that the amount of flow resulting from a temperature change is
not significant compared to that due to infiltration, or by
connectinganddisconnectingthebagfromtheinnerringwhen
the water in the inner ring is at the same temperature.
5.9 If the soil being tested will later be subjected to
increased overburden stress, then the infiltration rate can be
expected to decrease as the overburden stress increases. Labo-
ratory hydraulic conductivity tests are recommended for stud-
iesoftheinfluenceoflevelofstressonthehydraulicproperties
FIG. 1 Schematic Of A Double-Ring Infiltrometer With A Sealed
Inner Ring
of the soil.
NOTE1—Thequalityoftheresultproducedbythisstandarddependson
the competence of the personnel performing it and the suitability of the
equipment and facilities being used. Agencies that meet the criteria of
flexible bag.After a known interval of time, the flexible bag is
Practice D3740 are generally considered capable of competent and
removedandweighed.Theweightloss,convertedtoavolume, objective testing, sampling, inspection, etc. Users of this standard are
cautioned that compliance with Practice D3740 does not in itself ensure
is equal to the amount of water that has infiltrated into the
reliable results. Reliable results depend on many factors; Practice D3740
ground. An infiltration rate is then determined from this
provides a means of evaluating some of those factors
volume of water, the area of the inner ring, and the interval of
time. This process is repeated and a plot of infiltration rate
6. Apparatus
versus time is constructed. The test is continued until the
6.1 Infiltrometer Rings—The rings shall be constructed of a
infiltration rate becomes steady or until it becomes equal to or
stiff, corrosion-resistant material such as metal, plastic, or
less than a specified value.
fiberglass. The shape of the rings can be circular or square.
However,squareringsarerecommendedbecauseitiseasierto
5. Significance and Use
excavate straight trenches in the soil. The rings can be of any
5.1 This test method provides a means to measure low
size provided: (1) the minimum width or diameter of the inner
infiltration rates associated with fine-grained, clayey soils, and
ring is 610 mm (24 in.); and (2) a minimum distance of 610
−7 −9
are in the range of 1×10 m/s to 1×10 m/s.
mm is maintained between the inner and outer ring. The
5.2 This test method is particularly useful for measuring following is a description of a set of rings that can be
liquid flow through soil moisture barriers such as compacted constructed from commonly available materials, incorporates
clay liner or covers used at waste disposal facilities, for canal the requirements described above, and has worked well in the
andreservoirliners,forseepageblankets,andforamendedsoil field.
liners such as those used for retention ponds or storage tanks. 6.1.1 Outer Ring—Asquare ring (Fig. 2) comprised of four
sheets of aluminum approximately 3.6 m by 910 mm by 2 mm
5.3 The purpose of the sealed inner ring is to: (1) provide a
(12 ft by 36 in. by 0.080 in.) The top edge of the aluminum
means to measure the actual amount of flow rather than a drop
sheetisbent90°inordertoproviderigidity.Aholeisprovided
in water elevation which is the flow measurement procedure
in the center of the top edge. One edge of each sheet is bent
used in Test Method D3385 and ( 2) to eliminate evaporation
90°. Holes are drilled along each side edge so that the sheets
losses.
canbeboltedatthecorners.Aflatrubbergasketprovidesaseal
5.4 The purpose of the outer ring is to promote one-
at each corner. A wire cable approximately 15 m long with a
dimensional, vertical flow beneath the inner ring. The use of
clamp may be needed to tie the top edges together.
large diameter rings and large depths of embedments helps to
6.1.2 Inner Ring—Asquare ring (Fig. 3), 1.52 m (5 ft) on a
ensure that flow is essentially one-dimensional.
side, made of fiberglass provided with two ports. The top is
shaped in such a way as to vent air from the ring as it is filled.
5.5 This test method provides a means to measure infiltra-
tion rate over a relatively large area of soil. Tests on large
volumes of soil can be more representative than tests on small
volumes of soil.
5.6 The data obtained from this test method are most useful
when the soil layer being tested has a uniform distribution of
pore space, and when the density and degree of saturation and
the hydraulic conductivity of the material underlying the soil
layer are known.
5.7 Changes in water temperature can introduce significant
error in the volume change measurements. Temperature
changeswillcausewatertoflowinoroutoftheinnerringdue
to expansion or contraction of the inner ring and the water
contained within the inner ring. FIG. 2 Panel For Outer Ring
D5093−02 (2008)
6.5.4 Hand Shovel, garden type.
6.6 Levels—A surveyor’s level and rod and a carpenter’s
level.
6.7 Buckets—Fivebucketswithacapacityofapproximately
20 L (5 gal.)
6.8 Blocks—Cinder blocks to serve as a platform for the
flexible bag.
6.9 Cover—An opaque cover to place on top of the outer
ring.Thecovercanbeatarporplywoodsupportedbywooden
beams.
6.10 Grout—A bentonite grout for filling the trenches and
sealing the rings in place.
6.11 Mixing Equipment—Alarge (four bag) grout mixer for
mixing the bentonite grout.
6.12 Trowel.
6.13 Thermometer—Readable to 0.5°C with a range of 0 to
50°C.
6.14 Scale—Capacity of 4000 g and an accuracy of 1 g.
6.15 Watch—Readable to 1 s.
6.16 Water Supply—Preferably water of the same quality as
that involved in the problem being examined. Approximately
5600 L (1400 gal) are needed for this test.
6.17 Splash Guard—Plywood, rubber sheet, or burlap 600
by 600 mm (2 by 2 ft).
7. Test Site
7.1 The test requires an area of approximately 7.3 by 7.3 m
FIG. 3 Inner Ring
(24 by 24 ft).
7.2 The slope to the test area should be no greater than
A port is provided at the highest point so that any air that
approximately 3%.
accumulates in the ring during the test can be flushed out. One
7.3 The test may be set up in a pit if infiltration rates are
port must be located at the top of the ring.The other port must
desired at depth rather than at the surface.
be located beneath the top port. A150 mm (6 in.) skirt, that is
7.4 The test area shall be covered with a sheet of plastic to
embedded into the soil, is provided along the edge of the ring.
keep the surface from drying.
Barbed fittings that accept flexible tubing are attached to the
ports. Handles are provided at each corner of the inner ring.
7.5 Representative samples of the soil to be tested shall be
taken before and after the test to determine its moisture
6.2 FlexibleBag—Twoclearflexiblebagswithacapacityof
content,density,andspecificgravity.Thethicknessofthelayer
1000 to 3000 mL. Intravenous bags available from medical
being tested shall be determined as well as the approximate
supplystoresworkwell.Ameansforattachingashut-offvalve
hydraulic conductivity of the layer beneath it.
to the bag shall be provided. The shut-off valve shall be
providedwithabarbedfittingthatwillconnecttotheinlettube
8. Procedure
on the inner ring.
8.1 Assembly of Outer Ring—Wipe off gaskets and side
6.3 Tubing—Clear, flexible tubing approximately 4.5 m (15
edges of the outer ring. Align gasket between the edges and
ft) long with a minimum ID of 6 mm ( ⁄4 in.)
bolt edges together.
6.4 Scissors or Knife.
8.2 Excavation of Trenches:
6.5 Excavation Tools. 8.2.1 Place both rings on the area to be tested. Center the
6.5.1 Mason’s Hammer—Hammer with a blade approxi- inner ring within the outer ring. Make sure that the outer ring
mately 120 mm long and 40 mm wide. is square by using the tape measure to check that the length of
6.5.2 Trenching Machine—Capable of excavating a trench the diagonals are equal.
with a maximum width of 150 mm (6 in.) and a depth of 460 8.2.2 If plastic is covering the test area, cut out thin strips
mm (18 in.) along the edge of each ring so that the trenches can be
6.5.3 Chain Saw—(Optional—see Note 2) Equipped with a excavated.Leaveasmuchoftheplasticonaspossibleinorder
carbide-tipped chain and bar. to keep the soil from drying.
D5093−02 (2008)
8.2.3 Usethebottomedgeofeachringtoscribealineonthe 8.3.9 Use the carpenter’s level to make sure that the ring is
ground to use as a guide for excavating the trenches. level.
8.3.10 Useatroweltopushthegroutagainstboththeinside
8.2.4 Note the orientation of the rings and set them aside.
and the outside of the ring to ensure a good seal.
8.2.5 Use the surveyor’s level and check the ground eleva-
8.3.11 Cover the grout with plastic to prevent desiccation.
tionwherethecornersofeachringwillbe.Notethehighspots
8.3.12 Place several cinder blocks between the inner and
and excavate deeper in these areas so that the rings will be
outer rings in the vicinity of the ports on the inner ring. These
level.
blocks will be used as a platform to stand on when connecting
8.2.6 Use the trenching machine and excavate a trench for
the fittings to the inner ring and also to support the flexible
the outer ring. The trench should be about 146 mm (18 in.)
bags. The blocks should be no higher than 100 mm (4 in.)
deep. Excavate deeper at high spots.
8.3.13 Pilesoilalongtheoutsideoftheouterringtoaheight
8.2.7 Use a small hand shovel to remove any loose material
of at least 30 cm (12 in.) This soil places an overburden
in the trenches.
pressureonthegroutthatwillpreventitfrombeingpushedout
8.2.8 Place the outer ring in the trench and use the carpen-
of the trench when the rings are filled with water.
ter’s level to check that the top of the ring is reasonably level
(630 mm). Also check that the outer ring is square. Remove
8.4 Filling the Rings:
the ring and excavate any areas keeping the ring from being
8.4.1 Fill two buckets with water and place one on each
level and square.
back corner of the inner ring. The buckets are placed on the
8.2.9 Set the outer ring aside and cover the trenches to inner ring to counteract the uplift force that acts on the ring as
prevent the soil from drying. it is being filled. Make sure that the buckets are placed on the
8.2.10 Usethemason’shammerandexc
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it 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 version
of the standard as published by ASTM is to be considered the official document.
Designation:D5093–90(Reapproved 1997) Designation: D 5093 – 02 (Reapproved 2008)
Standard Test Method for
Field Measurement of Infiltration Rate Using a Double-Ring
Infiltrometer with a Sealed-Inner Ring
This standard is issued under the fixed designation D5093; 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
1.1 Thistestmethoddescribesaprocedureformeasuringtheinfiltrationrateofwaterthroughin-placesoilsusingadouble-ring
infiltrometer with a sealed inner ring.
−7 −10
1.2 This test method is useful for soils with infiltration rates in the range of 1 310 m/s to 1 310 m/s. When infiltration
−7
rates$1 310 m/s are to be measured Test Method D3385 shall be used.
1.3This test method provides a direct measurement of infiltration rate, not hydraulic conductivity. Although the units of
infiltration rate and hydraulic conductivity are similar, there is a distinct difference between these two quantities. They cannot be
directly related unless the hydraulic boundary conditions, such as hydraulic gradient and the extent of lateral flow of water are
known or can be reliably estimated.
1.4This test method can be used for natural soil deposits, recompacted soil layers, and amended soils such as soil bentonite and
soil lime mixtures.
1.5The values stated in SI units are to be regarded as standard. The values in parentheses are for information only.
1.6
1.3 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice
D6026.
1.3.1 The method used to specify how data are collected, calculated, or recorded in this standard is not directly related to the
accuracytowhichthedatacanbeappliedindesignorotheruses,orboth.Howoneappliestheresultsobtainedusingthisstandard
is beyond its scope.
1.4 This test method provides a direct measurement of infiltration rate, not hydraulic conductivity. Although the units of
infiltration rate and hydraulic conductivity are similar, there is a distinct difference between these two quantities. They cannot be
directly related unless the hydraulic boundary conditions, such as hydraulic gradient and the extent of lateral flow of water are
known or can be reliably estimated.
1.5 Thistestmethodcanbeusedfornaturalsoildeposits,recompactedsoillayers,andamendedsoilssuchassoilbentoniteand
soil lime mixtures.
1.6 The values stated in SI units are to be regarded as standard. The values in parentheses are for information only.
1.7 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.
2. Referenced Documents
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained Fluids
D3385Test Method for Infiltration Rate of Soils in Field Using Double Ring Infiltrometers Test Method for Infiltration Rate
of Soils in Field Using Double-Ring Infiltrometer
D3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in
Engineering Design and Construction
D6026 Practice for Using Significant Digits in Geotechnical Data
ThistestmethodisunderthejurisdictionofASTMCommitteeD-18onSoilandRockandisthedirectresponsibilityofSubcommitteeD18.04onHydrologicProperties
of Soil and Rocks.
Current edition approved June 29, 1990. Published August 1990.
This test method is under the jurisdiction ofASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.04 on Hydrologic Properties
and Hydraulic Barriers.
Current edition approved Sept. 1, 2008. Published September 2008. Originally approved in 1990. Last previous edition approved in 2002 as D5093–02.
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.For Annual Book of ASTM Standards
, Vol 04.08.volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 5093 – 02 (2008)
3. Terminology
3.1 Definitions:
3.1.1 infiltration—downward entry of liquid into a porous body.
3 2
3.1.2 infiltrationrate,I—quantityofliquidenteringaporousmaterial(m )perunitarea(m )perunittime(s),expressedinunits
of m/s.
3.1.3 infiltrometer—adeviceusedtopondliquidonaporousbodyandtoallowforthemeasurementoftherateatwhichliquid
enters the porous body.
3.1.4 For definitions of other terms used in this test method, see Terminology D653.
4. Summary of Test Method
4.1 The infiltration rate of water through soil is measured using a double-ring infiltrometer with a sealed or covered inner ring
(Fig. 1). The infiltrometer consists of an open outer and a sealed inner ring. The rings are embedded and sealed in trenches
excavated in the soil. Both rings are filled with water such that the inner ring is submerged.
4.2 The rate of flow is measured by connecting a flexible bag filled with a known weight of water to a port on the inner ring.
As water infiltrates into the ground from the inner ring, an equal amount of water flows into the inner ring from the flexible bag.
After a known interval of time, the flexible bag is removed and weighed. The weight loss, converted to a volume, is equal to the
amount of water that has infiltrated into the ground.An infiltration rate is then determined from this volume of water, the area of
the inner ring, and the interval of time. This process is repeated and a plot of infiltration rate versus time is constructed. The test
is continued until the infiltration rate becomes steady or until it becomes equal to or less than a specified value.
5. Significance and Use
5.1 Thistestmethodprovidesameanstomeasurelowinfiltrationratesassociatedwithfine-grained,clayeysoils,andareinthe
−7 −9
range of 1 310 m/s to 1 310 m/s.
5.2 Thistestmethodisparticularlyusefulformeasuringliquidflowthroughsoilmoisturebarrierssuchascompactedclayliner
or covers used at waste disposal facilities, for canal and reservoir liners, for seepage blankets, and for amended soil liners such
as those used for retention ponds or storage tanks.
5.3 The purpose of the sealed inner ring is to: (1) provide a means to measure the actual amount of flow rather than a drop in
water elevation which is the flow measurement procedure used in Test Method D3385 and ( 2) to eliminate evaporation losses.
5.4 Thepurposeoftheouterringistopromoteone-dimensional,verticalflowbeneaththeinnerring.Theuseoflargediameter
rings and large depths of embedments helps to ensure that flow is essentially one-dimensional.
5.5 This test method provides a means to measure infiltration rate over a relatively large area of soil. Tests on large volumes
of soil can be more representative than tests on small volumes of soil.
5.6 The data obtained from this test method are most useful when the soil layer being tested has a uniform distribution of pore
space, and when the density and degree of saturation and the hydraulic conductivity of the material underlying the soil layer are
known.
5.7 Changesinwatertemperaturecanintroducesignificanterrorinthevolumechangemeasurements.Temperaturechangeswill
cause water to flow in or out of the inner ring due to expansion or contraction of the inner ring and the water contained within
the inner ring.
5.8 The problem of temperature changes can be minimized by insulating the rings, by allowing enough flow to occur so that
the amount of flow resulting from a temperature change is not significant compared to that due to infiltration, or by connecting
and disconnecting the bag from the inner ring when the water in the inner ring is at the same temperature.
5.9 If the soil being tested will later be subjected to increased overburden stress, then the infiltration rate can be expected to
decrease as the overburden stress increases. Laboratory hydraulic conductivity tests are recommended for studies of the influence
of level of stress on the hydraulic properties of the soil.
NOTE 1—The quality of the result produced by this standard depends on the competence of the personnel performing it and the suitability of the
equipment and facilities being used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective
FIG. 1 Schematic Of A Double-Ring Infiltrometer With A Sealed
Inner Ring
D 5093 – 02 (2008)
testing, 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 of evaluating some of those factors
6. Apparatus
6.1 InfiltrometerRings—Theringsshallbeconstructedofastiff,corrosion-resistantmaterialsuchasmetal,plastic,orfiberglass.
The shape of the rings can be circular or square. However, square rings are recommended because it is easier to excavate straight
trenches in the soil. The rings can be of any size provided: (1) the minimum width or diameter of the inner ring is 610 mm (24
in.); and (2) a minimum distance of 610 mm is maintained between the inner and outer ring. The following is a description of a
set of rings that can be constructed from commonly available materials, incorporates the requirements described above, and has
worked well in the field.
6.1.1 Outer Ring—Asquare ring (Fig. 2) comprised of four sheets of aluminum approximately 3.6 m by 910 mm by 2 mm (12
ft by 36 in. by 0.080 in.) The top edge of the aluminum sheet is bent 90° in order to provide rigidity. A hole is provided in the
center of the top edge. One edge of each sheet is bent 90°. Holes are drilled along each side edge so that the sheets can be bolted
at the corners. A flat rubber gasket provides a seal at each corner. A wire cable approximately 15 m long with a clamp may be
needed to tie the top edges together.
6.1.2 Inner Ring—Asquare ring (Fig. 3), 1.52 m (5 ft) on a side, made of fiberglass provided with two ports.The top is shaped
in such a way as to vent air from the ring as it is filled. A port is provided at the highest point so that any air that accumulates
intheringduringthetestcanbeflushedout.Oneportmustbelocatedatthetopofthering.Theotherportmustbelocatedbeneath
thetopport.A150mm(6in.)skirt,thatisembeddedintothesoil,isprovidedalongtheedgeofthering.Barbedfittingsthataccept
flexible tubing are attached to the ports. Handles are provided at each corner of the inner ring.
6.2 Flexible Bag—Twoclearflexiblebagswithacapacityof1000to3000mL.Intravenousbagsavailablefrommedicalsupply
stores work well. A means for attaching a shut-off valve to the bag shall be provided. The shut-off valve shall be provided with
a barbed fitting that will connect to the inlet tube on the inner ring.
6.3 Tubing—Clear, flexible tubing approximately 4.5 m (15 ft) long with a minimum ID of 6 mm ( ⁄4 in.)
6.4 Scissors or Knife.
6.5 Excavation Tools.
6.5.1 Mason’s Hammer—Hammer with a blade approximately 120 mm long and 40 mm wide.
6.5.2 Trenching Machine—Capable of excavating a trench with a maximum width of 150 mm (6 in.) and a depth of 460 mm
(18 in.)
6.5.3 Chain Saw—(Optional—see Note 1Note 2) Equipped with a carbide-tipped chain and bar.
6.5.4 Hand Shovel, garden type.
6.6 Levels—A surveyor’s level and rod and a carpenter’s level.
6.7 Buckets—Five buckets with a capacity of approximately 20 L (5 gal.)
6.8 Blocks—Cinder blocks to serve as a platform for the flexible bag.
6.9 Cover—Anopaquecovertoplaceontopoftheouterring.Thecovercanbeatarporplywoodsupportedbywoodenbeams.
6.10 Grout—A bentonite grout for filling the trenches and sealing the rings in place.
6.11 Mixing Equipment—A large (four bag) grout mixer for mixing the bentonite grout.
6.12 Trowel.
6.13 Thermometer—Readable to 0.5°C with a range of 0 to 50°C.
6.14 Scale—Capacity of 4000 g and an accuracy of 1 g.
6.15 Watch—Readable to 1 s.
6.16 Water Supply—Preferablywaterofthesamequalityasthatinvolvedintheproblembeingexamined.Approximately5600
L (1400 gal) are needed for this test.
6.17 Splash Guard—Plywood, rubber sheet, or burlap 600 by 600 mm (2 by 2 ft).
7. Test Site
7.1 The test requires an area of approximately 7.3 by 7.3 m (24 by 24 ft).
FIG. 2 Panel For Outer Ring
D 5093 – 02 (2008)
FIG. 3 Inner Ring
7.2 The slope to the test area should be no greater than approximately 3%.
7.3 The test may be set up in a pit if infiltration rates are desired at depth rather than at the surface.
7.4 The test area shall be covered with a sheet of plastic to keep the surface from drying.
7.5 Representative samples of the soil to be tested shall be taken before and after the test to determine its moisture content,
density, and specific gravity. The thickness of the layer being tested shall be determined as well as the approximate hydraulic
conductivity of the layer beneath it.
8. Procedure
8.1 Assembly of Outer Ring—Wipe off gaskets and side edges of the outer ring.Align gasket between the edges and bolt edges
together.
8.2 Excavation of Trenches:
8.2.1 Placebothringsontheareatobetested.Centertheinnerringwithintheouterring.Makesurethattheouterringissquare
by using the tape measure to check that the length of the diagonals are equal.
8.2.2 If plastic is covering the test area, cut out thin strips along the edge of each ring so that the trenches can be excavated.
Leave as much of the plastic on as possible in order to keep the soil from drying.
8.2.3 Use the bottom edge of each ring to scribe a line on the ground to use as a guide for excavating the trenches.
8.2.4 Note the orientation of the rings and set them aside.
8.2.5 Use the surveyor’s level and check the ground elevation where the corners of each ring will be. Note the high spots and
excavate deeper in these areas so that the rings will be level.
8.2.6 Use the trenching machine and excavate a trench for the outer ring. The trench should be about 146 mm (18 in.) deep.
Excavate deeper at high spots.
8.2.7 Use a small hand shovel to remove any loose material in the trenches.
8.2.8 Place the outer ring in the trench and use the carpenter’s level to check that the top of the ring is reasonably level (630
mm). Also check that the ou
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