ASTM D6706-01(2021)
(Test Method)Standard Test Method for Measuring Geosynthetic Pullout Resistance in Soil
Standard Test Method for Measuring Geosynthetic Pullout Resistance in Soil
SIGNIFICANCE AND USE
5.1 The pullout test method is intended as a performance test to provide the user with a set of design values for the test conditions examined.
5.1.1 The test method is applicable to all geosynthetics and all soils.
5.1.2 This test method produces test data, which can be used in the design of geosynthetic-reinforced retaining walls, slopes, and embankments, or in other applications where resistance of a geosynthetic to pullout under simulated field conditions is important.
5.1.3 The test results may also provide information related to the in-soil stress-strain response of a geosynthetic under confined loading conditions.
5.2 The pullout resistance versus normal stress plot obtained from this test is a function of soil gradation, plasticity, as-placed dry unit weight, moisture content, length and surface characteristics of the geosynthetic, and other test parameters. Therefore, results are expressed in terms of the actual test conditions. The test measures the net effect of a combination of pullout mechanisms, which may vary depending on type of geosynthetic specimen, embedment length, relative opening size, soil type, displacement rate, normal stress, and other factors.
5.3 Information between laboratories on precision is incomplete. In cases of dispute, comparative tests to determine if there is a statistical bias between laboratories may be advisable.
SCOPE
1.1 Resistance of a geosynthetic to pullout from soil is determined using a laboratory pullout box.
1.2 The test method is intended to be a performance test conducted as closely as possible to replicate design or as-built conditions. It can also be used to compare different geosynthetics, soil types, etc., and thereby be used as a research and development test procedure.
1.3 The values stated in SI units are to be regarded as standard. The values stated in parentheses are provided for information only.
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D6706 − 01 (Reapproved 2021)
Standard Test Method for
Measuring Geosynthetic Pullout Resistance in Soil
This standard is issued under the fixed designation D6706; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 Resistance of a geosynthetic to pullout from soil is 3.1 Definitions of Terms Specific to This Standard:
determined using a laboratory pullout box.
3.1.1 apertures, n—the open spaces in geogrids which
enable soil interlocking to occur.
1.2 The test method is intended to be a performance test
conducted as closely as possible to replicate design or as-built
3.1.2 atmosphere for testing geosynthetics, n—air main-
conditions. It can also be used to compare different
tained at a relative humidity of 60 6 10 % and a temperature
geosynthetics,soiltypes,etc.,andtherebybeusedasaresearch
of 21 6 2 °C (70 6 4 °F).
and development test procedure.
3.1.3 cross-machine direction, n—the direction in the plane
1.3 The values stated in SI units are to be regarded as
of the geosynthetic perpendicular to the direction of manufac-
standard. The values stated in parentheses are provided for
ture.
information only.
3.1.4 failure, n—a defined point at which a material ceases
1.4 This standard does not purport to address all of the
to be functionally capable of its intended use.
safety concerns, if any, associated with its use. It is the
3.1.5 geosynthetic, n—a planar product manufactured from
responsibility of the user of this standard to establish appro-
polymeric material used with soil, rock, earth, or other geo-
priate safety, health, and environmental practices and deter-
technical engineering related material as an integral part of a
mine the applicability of regulatory limitations prior to use.
man-made project, structure, or system. (D4439)
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3.1.6 junction, n—the point where geogrid ribs are intercon-
ization established in the Decision on Principles for the
nected in order to provide structure and dimensional stability.
Development of International Standards, Guides and Recom-
3.1.7 machine direction, n—the direction in the plane of the
mendations issued by the World Trade Organization Technical
geosynthetic parallel to the direction of manufacture.
Barriers to Trade (TBT) Committee.
3.1.8 pullout, n—the movement of a geosynthetic over its
2. Referenced Documents
entire embedded length, with initial pullout occurring when the
back of the specimen moves, and ultimate pullout occurring
2.1 ASTM Standards:
when the movement is uniform over the entire embedded
D123 Terminology Relating to Textiles
length.
D653 Terminology Relating to Soil, Rock, and Contained
Fluids
3.1.9 pullout force, (kN),n—force required to pull a geo-
D3080 Test Method for Direct Shear Test of Soils Under
synthetic out of the soil during a pullout test.
Consolidated Drained Conditions
3.1.10 pullout resistance, (kN/m),n—the pullout force per
D4354 Practice for Sampling of Geosynthetics and Rolled
width of geosynthetic measured at a specified condition of
Erosion Control Products (RECPs) for Testing
displacement.
D4439 Terminology for Geosynthetics
3.1.11 rib, n—the continuous elements of a geogrid which
are either in the machine or cross-machine direction as
This test method is under the jurisdiction of ASTM Committee D35 on
manufactured.
Geosynthetics and is the direct responsibility of Subcommittee D35.01 on Mechani-
cal Properties.
3.1.12 ultimate pullout resistance, (kN/m),n—the maxi-
Current edition approved Sept. 1, 2021. Published September 2021. Originally
mum pullout resistance measured during a pullout test.
approved in 2001. Last previous edition approved in 2013 as D6706 – 01 (2013).
DOI: 10.1520/D6706-01R21.
3.1.13 wire gauge, n—a displacement gauge consisting of a
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
non-extensiblewireattachedtothegeosyntheticandmonitored
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
by connection to a dial extensometer or electronic displace-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. ment transducer.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6706 − 01 (2021)
3.2 For definitions of other terms used in this test method, geosynthetic specimen, embedment length, relative opening
refer to Terminologies D123, D653, and D4439. size, soil type, displacement rate, normal stress, and other
factors.
4. Summary of Test Method
5.3 Information between laboratories on precision is incom-
4.1 Inthismethod,ageosyntheticisembeddedbetweentwo
plete. In cases of dispute, comparative tests to determine if
layers of soil, horizontal force is applied to the geosynthetic,
there is a statistical bias between laboratories may be advis-
and the force required to pull the geosynthetic out of the soil is
able.
recorded.
4.2 Pullout resistance is obtained by dividing the maximum 6. Apparatus
load by the test specimen width.
6.1 Pullout Box—An open rigid box consisting of two
4.3 The test is performed while subjected to normal com- smooth parallel sides, a back wall, a horizontal split removable
pressive stresses which are applied to the top soil layer. door, a bottom plate, and a load transfer sleeve. The door is at
the front as defined by the direction of applied pullout force.A
4.4 A plot of maximum pullout resistance versus applied
typical box is shown in Fig. 1.
normal stress is obtained by conducting a series of such tests.
6.1.1 The box should be square or rectangular with mini-
mum dimensions 610 mm (24 in.) long by 460 mm (18 in.)
5. Significance and Use
wide by 305 mm (12 in.) deep, if sidewall friction is
5.1 The pullout test method is intended as a performance
minimized, otherwise the minimum width should be 760 mm
test to provide the user with a set of design values for the test
(30 in.). The dimensions should be increased, if necessary, so
conditions examined.
that minimum width is the greater of 20 times the D85 of the
5.1.1 The test method is applicable to all geosynthetics and
soil or six times the maximum soil particle size, and the
all soils.
minimum length greater than five times the maximum geosyn-
5.1.2 Thistestmethodproducestestdata,whichcanbeused
thetic aperture size. The box shall allow for a minimum depth
inthedesignofgeosynthetic-reinforcedretainingwalls,slopes,
of150mm(6in.)aboveandbelowthegeosynthetic.Thedepth
and embankments, or in other applications where resistance of
of the soil in the box above or below the geosynthetic shall be
a geosynthetic to pullout under simulated field conditions is
a minimum of six times the D85 of the soil or three times the
important.
maximum particle size of the soil, whichever is greater. The
5.1.3 The test results may also provide information related
box must allow for at least 610 mm (24 in.) embedment length
to the in-soil stress-strain response of a geosynthetic under
beyond the load transfer sleeve and a minimum specimen
confined loading conditions.
length to width ratio of 2.0. It should be understood that when
5.2 Thepulloutresistanceversusnormalstressplotobtained
testing large aperture geosynthetics the actual pullout box may
from this test is a function of soil gradation, plasticity,
have to be larger than the stated minimum dimensions.
as-placed dry unit weight, moisture content, length and surface
NOTE 1—To remove sidewall friction as much as possible, a high-
characteristics of the geosynthetic, and other test parameters.
density polyethylene (HDPE) geomembrane should be bonded to the
Therefore, results are expressed in terms of the actual test
inside surfaces of the pullout box.The sidewalls may also be covered with
conditions.The test measures the net effect of a combination of
a layer of silk fabric, which has been shown to eliminate adhesion and has
pullout mechanisms, which may vary depending on type of a very low friction value. Alternatively, a lubricant can be spread on the
FIG. 1 Experimental Setup for Geosynthetic Pullout Testing
D6706 − 01 (2021)
sidewalls of the box and thin sheets of polyethylene film used to minimize
6.3 Pullout Force Loading Device—Pullout force must be
the sidewall friction. It should be also noted that the effect of sidewall
supplied by a device with the ability to pull the geosynthetic
friction on the soil-geosynthetic interface can also be eliminated if a
horizontally out of the pullout box. The force must be at the
minimum distance is kept between the specimen and the sidewall. This
same level with the specimen.The pullout system must be able
minimum distance is recommended to be 150 mm (6 in.).
to apply the pullout force at a constant rate of displacement,
6.1.2 The box shall be fitted with a metal sleeve at the
slow enough to dissipate soil pore pressures as outlined in Test
entrance of the box to transfer the force into the soil to a
MethodD3080.Ifexcessporepressuresarenotanticipatedand
sufficient horizontal distance so as to significantly reduce the
in the absence of a material specification, apply the pullout
stress on the door of the box. The sleeve, as shown in Fig. 2,
forceatarateof1mm/min 610%,andthepulloutrateshould
shall consist of two thin plates (no more than 13 mm (0.5 in.)
be monitored during testing; see Note 2. Also, a device to
thick) extending the full width of the pullout box and into the
measure the pullout force such as a load cell or proving ring
pullout box a minimum distance of 150 mm (6 in.) but it is
recommendedthatthisdistanceequalthetotalsoildepthabove must be incorporated into the system and shall be accurate
orbelowthegeosynthetic.Theplatesshallbetaperedasshown within 60.5 % of its full-scale range.
in Fig. 2, such that at the point of load application in the soil,
NOTE 2—Pullout tests may also be conducted using a constant stress
the plates forming the sleeve are no more then 3 mm (0.12 in.)
loading approach. This approach can be achieved using one of the three
thick. The plates shall be rigidly separated at the sides with
methods described: (1) controlled stress rate method (short-term loading
spacers and be sufficiently stiff such that normal stress is not
condition) where the pullout force is applied to the geosynthetic under a
transferred to the geosynthetic between the plates.
uniform rate of load application, not exceeding 2 kN/m/min until pullout
or failure of the geosynthetic is achieved; (2) incremental stress method
6.2 Normal Stress Loading Device—Normal stress applied
(short-term loading condition) where the pullout force is applied in
to the upper layer of soil above the geosynthetic must be
uniform or doubling increments and held for a specific time before
constant and uniform for the duration of the test. To maintain
proceedingtothenextincrement,asagreedtobythepartiesinvolveduntil
a uniform normal stress, a flexible pneumatic or hydraulic
pullout or failure of the geosynthetic is achieved; and (3) constant stress
diaphragm-loading device which is continuous over the entire (creep) method (long-term loading condition) where the pullout force is
applied using one of the first two methods mentioned above to achieve the
pullout box area should be used and capable of maintaining the
required constant stress for the test. The constant stress is maintained and
applied normal stress within 62 % of the required normal
the test specimen is monitored over time for the duration of time agreed
stress. Normal stresses utilized will depend on testing require-
to by the parties involved (i.e., typically 100 to 10 000 h depending on
ments; however, stresses up to 250 kPa (35 psi) should be
application). It should be noted that the constant stress procedures
anticipated.Arecommended normal stress-loading device is an
described above have not been widely researched and comparisons with
air bag as shown in Fig. 2. the constant strain method have not been determined.
FIG. 2 Cross-Sectional Detail View for Geosynthetic Pullout Setup
D6706 − 01 (2021)
modification is the addition of a metal rod behind the back flange which
6.4 Displacement Indicators—Horizontal displacement of
allowsloopingofthematerialaroundtherodandbackintotheclamp.The
the geosynthetic is measured at the entrance of the pullout box
use of epoxy bonding within the clamp is generally recommended when
and at several locations on the embedded portion of the
accurate measurement of the geosynthetic displacements within the soil
specimen. Measurements outside the door at the pullout box
are required.
entrance are made by a dial extensometer or electronic dis-
6.6 Soil Preparation Equipment—Use equipment as neces-
placement transducers (e.g. liner variable differential trans-
sary for the placement of soils at desired conditions. This may
formers (LVDTs) can be used) mounted to the box frame to
include compaction devices such as vibratory or “jumping-
read against a plate attached to the specimen near the door.
jack” type compaction, or hand compaction hammers. Soil
6.4.1 Determine the displacement of the geosynthetic at a
container or hopper, leveling tools, and soil placement/removal
minimum of three equally spaced distances from the clamping
tools may be required.
plates. Displacement measurements within the box may em-
6.7 Miscellaneous Equipment—Measurement and trimming
ploy any of several methods, which place sensors or gauge
equipment as necessary for geosynthetic preparation, a timing
connectors directly on the geosynthetic and monitor their
device, and soil property testing equipment if desired.
change in location remotely. One such device utilizes wire
gauges, which are protected from normal stress by a surround-
7. Geosynthetic Sampling
ing tube, which runs from a location mounted on the specimen
7.1 Lot Sample—Divide the product into lots and for any lot
to the outside of the box where displacements are measured by
to be tested, take the lot samples as directed in Practice D4354;
a dial indicator or electronic displacement transducer.Atypical
see Note 4.
instrumentation setup is shown in Fig. 3.
6.4.2 All dial gauges or electronic measurement devices NOTE 4—Lots of geosy
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