ASTM D4719-20

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: D4719 − 20
Standard Test Methods for
Prebored Pressuremeter Testing in Soils
This standard is issued under the fixed designation D4719; 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* 1.5 All observed and calculated values shall conform to the
guidelines for significant digits and rounding established in
1.1 This test method covers pressuremeter testing of soils at
Practice D6026.
a given depth in the ground within a suitable prebored, open
1.6 The procedures used to specify how data are collected/
test cavity.The pressuremeter test is an in situ, stress-strain test
recorded and calculated in this standard are regarded as the
performed on the wall of a test cavity using a circular
industry standard. In addition, they are representative of the
cylindricalprobethatisexpandedradially.Toobtainviabletest
results, disturbance of the test cavity must be minimized with significant digits that should generally be retained. The proce-
dures used do not consider material variation, purpose for
minimal clearance between the diameter of the probe and the
test cavity. Alternatively, when preboring does not provide an obtaining the data, special purpose studies, or any consider-
ations for the user’s objectives; and it is common practice to
acceptable test cavity, the probe may be directly inserted into
the ground to form the test cavity. increase or reduce significant digits of reported data to be
commensuratewiththeseconsiderations.Itisbeyondthescope
1.2 This test method includes the procedure for test cavity
of this standard to consider significant digits used in analysis
preparation, inserting the probe, and conducting pressuremeter
methods for engineering design.
tests in both granular and cohesive soils, but does not include
1.7 The text of this standard references notes and footnotes
high pressure testing in rock. Knowledge of the type of soil to
which provide explanatory material. These notes and footnotes
be tested is necessary for assessment of (1) the method of
(excluding those in tables and figures) shall not be considered
preparing the test cavity, (2) the interpretation of the test data,
as requirements of the standard.
and (3) the acceptability of the test results.
1.8 The values stated in SI units are to be regarded as the
1.3 This test method does not cover the self-boring
standard. No other units of measurement are included in this
pressuremeter, for which the hole is drilled by a mechanical or
standard. Reporting of test results in units other than SI shall
jetting tool inside the hollow core of the probe. This test
not be regarded as non-conformance with this test method.
method is limited to the type of pressuremeter that is inserted
into predrilled boreholes or, under certain circumstances, is
1.9 This standard does not purport to address all of the
inserted by driving or pushing.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
1.4 Two alternative testing procedures are provided as
priate safety, health, and environmental practices and deter-
follows:
mine the applicability of regulatory limitations prior to use.
1.4.1 Procedure A—Equal Pressure Increments
1.10 This international standard was developed in accor-
1.4.2 Procedure B—Equal Volume Increments
dance with internationally recognized principles on standard-
NOTE 1—Pressuremeter tests performed in rock or using the self-boring
ization established in the Decision on Principles for the
pressuremeterfollowsimilartestprocedurestothosedescribedherein,but
Development of International Standards, Guides and Recom-
do not fall within the scope of this test method.
mendations issued by the World Trade Organization Technical
NOTE 2—Strain-controlled tests also can be performed, whereby the
Barriers to Trade (TBT) Committee.
probe volume is increased at a constant rate and corresponding pressures
are measured. Strain-controlled tests may yield different results than the
2. Referenced Documents
procedures described in this test method.
2.1 ASTM Standards:
D653 Terminology Relating to Soil, Rock, and Contained
1 Fluids
These test methods are under the jurisdiction ofASTM Committee D18 on Soil
and Rock and is the direct responsibility of Subcommittee D18.02 on Sampling and
Related Field Testing for Soil Evaluations.
Current edition approved Jan. 1, 2020. Published January 2020. Originally For referenced ASTM standards, visit the ASTM website, www.astm.org, or
approved in 1987. Last previous edition approved in 2007 as D4719 – 07, which contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
was withdrawn January 2016 and reinstated in January 2020. DOI: 10.1520/D4719- Standards volume information, refer to the standard’s Document Summary page on
20. the ASTM website.
*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
D4719 − 20
D1586 Test Method for Standard PenetrationTest (SPT) and 4.2 An open test cavity is typically prepared for the probe
Split-Barrel Sampling of Soils by preboring a hole with an appropriate diameter. The various
D1587 Practice for Thin-Walled Tube Sampling of Fine- tools and methods available to prepare the cavity produce
Grained Soils for Geotechnical Purposes different degrees of disturbance. The test cavity may also be
D2113 Practice for Rock Core Drilling and Sampling of created by inserting the pressuremeter probe directly into the
Rock for Site Exploration ground, usually within a slotted tube. However, direct insertion
D3740 Practice for Minimum Requirements for Agencies may significantly affect test results. Recommended method(s)
Engaged in Testing and/or Inspection of Soil and Rock as of test cavity preparation, described below, depend on soil
Used in Engineering Design and Construction conditions at the test site.
D5778 Test Method for Electronic Friction Cone and Piezo-
NOTE 4—It is recommended that several drilling techniques be avail-
cone Penetration Testing of Soils
able on the site to determine which method will provide the most suitable
D6026 Practice for Using Significant Digits in Geotechnical
test hole.
Data
5. Significance and Use
3. Terminology
5.1 This test method provides a radial stress-strain response
3.1 Definitions: ofthesoilinsitu.Apressuremetermodulusandalimitpressure
are obtained for use in geotechnical analysis and foundation
3.1.1 For definitions of common technical terms used in this
design. Correlations of the test results to soil strength and
standard, refer to Terminology D653.
stiffness and to engineering design applications are generally
3.2 Definitions of Terms Specific to This Standard:
empirical, and deviation from the methodology described in
3.2.1 limit pressure (p ), n—the pressure at which the probe
l
this test method may have undesirable effects.
volume reaches twice the original soil cavity volume.
NOTE 5—As with other in situ and laboratory test methods, the user
3.2.2 pressuremeter modulus (E ), n—the modulus calcu-
p
should consider whether results from this test are appropriate for the
lated from the slope of the pseudo-elastic portion of the
intended design use. Considerations may include whether the test directly
corrected pressure-volume curve, which includes little to no
measures strength or stiffness, the orientation of loading, the level of
induced strain, insertion or borehole disturbance effects, soil sensitivity,
creep.
soil saturation, drainage effects, and the robustness of the test equipment,
3.2.3 unload-reload modulus (E ), n—the pressuremeter
R
etc.
modulus calculated from an unload-reload loop.
5.2 The results of this test method are dependent on the
clearance between the test cavity and probe and the degree of
4. Summary of Test Method
ground disturbance caused by test cavity preparation and probe
4.1 The pressuremeter test consists of placing an inflatable,
insertion, all of which shall be considered during interpretation
cylindrical probe into a test cavity in the ground and then
of the test results. This disturbance is particularly significant in
expandingtheprobeintheradialdirectionwhilemeasuringthe
very soft clays and very loose sands. Disturbance may not be
changes in volume and pressure of the probe. The probe is
eliminated completely but shall be minimized for the prebored
inflated by equal pressure increments (Procedure A) or by
pressuremeter design rules to be applicable.
equal volume increments (Procedure B), and the test is
NOTE 6—The quality of the result produced by this standard is
terminated when yielding in the soil becomes disproportion-
dependent on the competence of the personnel performing it, and the
ately large. A conventional limit pressure for the soil is
suitability of the equipment and facilities used. Agencies that meet the
estimated from the last few readings of the test, and a soil criteria of Practice D3740 are generally considered capable of competent
and objective testing/sampling/ inspection/etc. Users of this test method
pressuremeter modulus is calculated from pressure-volume
are cautioned that compliance with Practice D3740 does not in itself
changes read during the test. The test must be performed in a
assure reliable results. Reliable results depend on many factors; Practice
test cavity with a diameter only slightly larger than that of the
D3740 provides a means of evaluating some of those factors.
probe. If this requirement is not met, the test could terminate
without reaching sufficient probe expansion in the soil to
6. Apparatus
permit evaluation of the limit pressure. The test cavity should
6.1 The pressuremeter apparatus consists of an inflatable
be of circular cylindrical shape. The instrument is either of the
probe placed inside a test cavity formed in the ground, lines
type where the change in volume of the probe is directly
connecting the probe to ground surface, and a control unit at
measured by an incompressible liquid or the type where feeler
the ground surface that is used to pressurize and monitor the
gages are used to determine the change in radius in the probe.
probe during the test. The same rods used to prepare the test
The volume-measuring type of system must be well protected
cavity are typically used to place the probe for testing.
against any volume losses throughout the system, while the
6.2 Probe—The probe shall be cylindrical and flexible for
feeler-typeprobemustbesensitivetorelativelysmalldisplace-
ments. Both types of measuring systems must be calibrated for inflation against the wall of the test cavity. The design of the
probe shall allow drill fluid in a borehole to flow freely past it
the effects of system pressurization.
without disturbing the borehole wall during insertion or re-
NOTE 3—This test method refers primarily to the type of apparatus
moval. Typical probe dimensions are indicated in Table 1.
where volume changes are recorded during the test. For the system
6.2.1 Hydraulic or Electronic Probe—The probe is either of
measuring probe radius change, alternate evaluation methods are given in
the notes. the hydraulic type or of the electronic type. A hydraulic probe
D4719 − 20
TABLE 1 Typical Probe and Borehole Dimensions
cellandtriple-cellpressuremetersthecombinedheightofallof
Probe Hole Diameter Borehole Diameter the cells shall be at least six probe diameters.
Diameter Designation Nominal (mm) Max. (mm)
6.2.3 Probe Walls—The flexible walls of the probe consist
(mm)
of a single rubber membrane (single-cell design) or of an inner
44 AX 45 53
58 BX 60 70 rubber membrane fitted with an outer flexible sheath or cover
74 NX 76 89
(triple-cell design), which will initially expand to contact the
test cavity wall as pressure is applied in the test cell and then
will deform the test cavity as pressure is further increased. In
is one in which all test data are measured indirectly at the
a coarse-grained material like gravel, a steel sheath made of
ground surface; no data are transmitted electronically from the
thin overlapping metal strips is often used.The accuracy of the
probe to the surface. In hydraulic probes, the test cell expan-
test will be impaired if the membrane cannot conform to the
sion is computed by measuring the quantity of fluid injected
shape of the test cavity.
into the test system and adjusting this volume for the system
NOTE 7—Various membrane and sheath, or cover, materials may be
compliance. The pressure in the test cell is computed as the
used to better accommodate different soil types; identify the membrane
sum of the pressure measured at the ground surface and the
and sheath, or cover, used in the report.
hydrostatic pressure between the surface gage and the test cell.
6.2.4 Measuring Devices—For the hydraulic probe, changes
Anelectronicprobeisoneinwhichthepressureinthetestcell,
in volume of the test cell of the probe are measured by the
or the expansion of the test cell, or both, are measured by
control unit. Alternatively, changes in the probe radius can be
devices inside the test cell, and the data are transmitted
measured by the use of feelers in the electronic apparatus.
electronically to a recorder at the ground surface. In the
Provisions to measure the change in probe radius in three
electronic probe, the test cell expansion may be measured
directions at 120° angles shall be provided with the electronic
electronically by the change in length of radial feelers using
apparatus.The measuring cell shall be prevented from expand-
linear variable differential transformers (LVDTs) or by strain
ing in the vertical direction by guard cells or other effective
gages. The pressure inside the test cell may be measured
restraints in the hydraulic apparatus.
electronically by a pressure transducer.
6.3 Lines—In the hydraulic apparatus, the lines connecting
6.2.2 Types of Probe—The hydraulic probe is of a single-
the probe to the readout device typically consist of plastic
cell or triple-cell design. Electronic probes typically have a
tubing. To reduce measuring errors, a coaxial tubing can be
single-cell design. The single-cell contains only a test cell that
used,wherebytheinnertubingispreventedfromexpandingby
changes in volume as the probe is pressurized. The triple-cell
gas pressure acting on its exterior surface. By applying the
probe contains upper and lower cells (guard cells) to provide
correct gas pressure, expansion of the inner tubing is reduced
effective end restraint against vertical expansion of the central
to a minimum. Single tubing can also be used. In both cases,
test cell and ensure purely radial expansion of the test cell (Fig.
the correction for volume losses given in 7.3 applies. Elec-
1a ). The stresses induced in the ground surrounding the test
tronic lines need special protection against groundwater.
cavitybytheguardcellsalsoenablethetestcelltoinducemore
uniform, purely radial stresses in the ground. For both single
6.4 Control Unit—The control unit includes a mechanism to
applypressure(ProcedureA)orvolume(ProcedureB)inequal
increments to the probe and readout devices to display the
Baguelin, F., Jézéquel, J.F., and Shields, D.H., “The Pressuremeter and
pressure and volume. The equipment using the hydraulic
Foundation Engineering,” Trans Tech Publications, Series on Rock and Soil
system and guard cells shall also include a regulator that
Mechanics, Vol 2, No. 4, 1978, p. 47.
maintains the pressure in the gas circuit below the fluid
pressure in the measuring cell. The magnitude of pressure
difference between gas and fluid must be adjustable to com-
pensate for hydrostatic pressures developing in the probe. In
the electronic system the volume change readings are replaced
by an electronic readout of the change in the probe radius.
6.5 Slotted Tube—A steel tube (Fig. 1b) with a series of
longitudinalslots(usuallysix)cutthroughittoallowforlateral
expansion is used sometimes as a protective housing when the
probe is driven, vibrodriven, or pushed into deposits where this
techniqueisapplicable(Table2).Thepressuremetertestisthen
performed within the slotted tube.
6.6 Accuracy and Readability of Measurements—Pressure
gages or transducers used to measure pressure shall have an
accuracy of 0.25 % or less of their full-scale span (FS) and
shall be readable to the nearest 10 kPa or less. Volume change
measurements shall have an accuracy of 0.25 % or less of their
FIG. 1 a) Basic Principles of the Triple Cell Design Pressureme-
FS and shall be readable to the nearest 1 mL or less. Systems
ter (Baguelin, Jézéquel and Shields, 1978), b) Slotted Tube with
Probe used to directly measure changes in test cell radius shall
D4719 − 20
A
TABLE 2 Guidelines for Selection of Borehole Preparation Methods and Tools
Rotary Driven
Pilot Hole Pilot Hole Hand Auger
Drilling Pushed Contin- Hand Driven Vibro-
Drilling and Drilling and With Bottom Core Rotary
With Bottom Thin uous Auger or Vibro- driven or
Soil Type Subsequent Simul- Discharge of Barrel Percus-
Discharge of Wall Flight in the driven Pushed
Sampler taneous Prepared Drilling sion
Prepared Sampler Auger Dry Sampler Slotted
Pushing Shaving Mud
Mud Tube
B B B
Clayey soils Soft 2 2 22 1 NR 1 NR NR NR NR
B
Firm to stiff 1 12 2 NR 1 1 NR NR NR NR
B B B
Stiff to hard 1 2 1 1 1 NA NA NA 1 2 NR
C B B B
Silty soils Above GWL 1 2 22 1 1 2 2 NR NR NR
C B B
Under GWL 1 NR NR 2 NR NR 1 NR NR NR NR
C B
Sandy soils Loose and above GWL 1 NR NR 2 2 2 1 2 NA NR NR
C B
Loose and below GWL 1 NR NR 2 NR NR 1 NR NA NR NR
B B
Medium to dense 1 NR NR 2 1 1 1 2 NR 2 NR
Sandy gravel or Loose 2 NA NA NA NA NA NA NR NA 2 2
D
gravely sands Dense NR NA NA NA NR NA NA NR NA 2 1
below GWL
B
Weathered rock . 1 NA 2 NA 1 NA NA 1 2 2 NR
A
1 is first choice; 2 is second choice; NR is not recommended; and NA is nonapplicable.
B
Method applicable only under certain conditions (see text for details).
C
GWL is groundwater level.
D
Pilot hole drilling required beforehand.
provide an accuracy of 0.25 % or less of the probe diameter must be deducted to obtain the actual pressure applied to the
and shall be readable to the nearest 0.1 mm or less. soil. Calibrations for membrane resistance shall be performed
by inflating the probe, completely exposed to the atmosphere,
7. Calibration of the Test Apparatus
with the probe placed at the level of the pressure gage.
7.2.1 Apply pressure in 10-kPa increments for ProcedureA
7.1 Perform calibrations for pressure and volume losses
and hold each increment for 60 s. Make volume readings after
after making any change in the test equipment that could affect
60 s of elapsed time. When Procedure B is used, increase the
these losses, that is, new membrane, lines, etc. In addition,
volume of the probe in increments equal to 5 % of the probe’s
repeat the pressure loss calibration after no more than ten tests,
zero volume. Apply each volume increase in about 10 s and
and the volume loss calibration at the beginning of each testing
hold constant for 30 s. Continue steps in both procedures until
day. Pressure loss calibrations have a more significant effect on
the maximum probe volume is reached. Plot results on a
test results in soft or loose soils, and in this case, require
pressureversusvolumeplot.Theresultingcurveisthepressure
additional calibrations for better accuracy. Additional calibra-
calibration curve. The pressure correction (P ) is the pressure
tions are also appropriate following tests performed to high
c
loss obtained from the calibration curve for the volume reading
deformation or high pressure and when the membrane has
(V)(Fig. 2).
visible signs of wear or damage.
r
7.2.2 The appropriate pressure correction (P ) must be
7.1.1 The control unit, lines, and probe of hydraulic systems
c
deducted from each of the pressure readings obtained during
must be calibrated as a complete system, and must be deaired
following manufacturer recommendations prior to calibration.
7.1.2 If measuring radius increase, then substitute radius
readings for all references to volume readings in this section.
7.1.3 The volume of the probe with the test apparatus at
atmosphericpressureshallbeestablishedduringthecalibration
process so that all tests begin with the same deflated volume as
during the calibrations. This is the zero volume, V,ofthe
probe. The volume readout of the control unit used for
hydraulic systems shall be adjusted to read zero with the probe
at the zero volume.
7.1.4 The temperature of the system shall be maintained as
closely as possible to the temperatures the system will encoun-
ter during testing. Avoid calibration in temperatures that are
significantly different than those that will be tested. If signifi-
cant temperature variations cannot be controlled during
calibration, the ambient temperature during calibration shall be
noted.
7.2 Pressure Losses—Pressure losses (P ) occur due to the
c
elasticity of the probe walls. The pressure readings obtained
NOTE 1—The schematic graphs are not to scale; each calibration
during the test on the readout device include the pressure
requires different volumes and pressures.
required to expand the probe walls. This membrane resistance FIG. 2 Calibration for Volume and Pressure Losses
D4719 − 20
the test. The maximum value of P shall be less than 50 % of
c
the limit pressure as defined in 10.6.
7.3 Volume Losses—Volume losses (V ) occur due to expan-
c
sion of the tubing and compressibility of any part of the test
apparatus, including the probe and the liquid. Calibration is
performed by pressurizing the equipment with the probe inside
heavy duty steel casing or pipe with an inside diameter that is
slightly larger than the probe diameter and a wall thickness of
atleast6mm.Asuggestedprocedureistoincreasethepressure
in steps of 100 kPa or 500 kPa, depending on whether the
probe is designed for a maximum expansion pressure of 2.5
MPa or 5.0 MPa, respectively. Each pressure increment shall
be reached within 20 s and, once in contact with the steel tube,
be held constant for 60 s. Record all volumes to the nearest 1
mL. The resulting graph of injected volume (V ) at the end of
r
each pressure increment (P ) is the volume calibration curve.
r
FIG. 3 DepthH for Determination of Hydrostatic Pressure in
Thezerovolume(V )isobtainedbyfittingastraightlinetothe Probe
curve and determining the intercept V at zero pressure, as
i
shown in Fig. 2. V can be used to estimate (V ) as follows:
i 0
pressure gages.This pressure must accordingly be added to the
V 5 ~π⁄4!LD 2 V (1)
0 i i
pressure readings obtained on the readout device.
where:
7.6 For triple cell pressuremeters, the pressure of the guard
D = inside diameter of the heavy duty steel casing or pipe cells (P ) must be set below the actual pressure generated in
i G
recorded to the nearest 1 mm, and the probe to provide effective end restraint. This is obtained by
L = length of the measuring cell recorded to the nearest 1 subtracting this pressure from the test pressures as follows:
mm.
P 5 P 1P 2 P (4)
G R δ d
7.3.1 The volume loss correction (V ) of the test apparatus
c
where:
for a particular pressure is obtained by using the factor (a)
P = guard cell pressure, kPa,
G
corresponding to the slope of the volume versus pressure
P = pressure reading on control unit, kPa,
R
calibration plot (Fig. 2) as follows:
P = hydrostatic pressure between control unit and probe,
δ
V 5 V 2 aP (2)
c r r kPa (see 7.5), and
P = pressure differences between guard cells and measur-
d
7.3.2 The appropriate volume loss correction (V ) must be
c
ing cell, kPa (usually twice the limit pressure of the
deducted from each volume measured during the test. This
membrane).
correctionisrelativelysmallinsoilsandcanbeneglectedifthe
7.6.1 Atabulation of gas and liquid pressures for a pressure
correction is less than 0.1 % of the nominal volume of the
difference of P = 100 kPa for various test depths is shown in
probe’suninflatedtestcell(V )per100kPaofpressure.Invery
d
Table 3.
hard soils or rock, the correction is significant and must be
applied. In no case shall this correction exceed 0.5 % of the
8. Test Cavity Preparation
nominal volume of the probe’s uninflated test cell (V ) per 100
kPa of pressure. 8.1 The pressuremeter test is performed within a test cavity
in the ground. Whenever possible, prebore an open test cavity.
7.4 Corrections for temperature changes and head losses
Alternatively, the test cavity may be formed by inserting the
due to circulating liquid are usually small and disregarded in
probe directly into the ground.Two conditions are necessary to
routine tests for soils. For tests at depths greater than 50 m,
obtain a satisfactory test cavity: the diameter of the prebored
special procedures are required to account for head losses.
hole shall meet the specified tolerances, and the equipment and
7.5 Unless the pressure within the test cell is measured
directly by a pressure transducer, the hydrostatic pressure (P )
δ
TABLE 3 Pressure Compensation for Guard Cells Based on Test
in kPa exerted on the probe by the column of liquid in the
Depth
testing equipment must be determined as follows:
Test Depth H, m Pressure from Head of Gas Pressure
P 5 H 3 δ (3) Test Liquid on Probe P, Reduction on Readout
δ t
A
kPa Gages P , kPa
d
where: 0 0 –100
5 50 –50
H = depth of probe below the control unit, m, and
10 100 0
δ = unit weight of the test liquid in the instrument, kN/m .
15 150 +50
t
20 200 +100
7.5.1 Thetestdepthoftheprobe(H)isthedistancefromthe
A
To maintain guard cell pressure 100 kPa below the measuring cell pressure,
center of the pressure gage to the center of the probe (Fig. 3).
deduct (–) or add (+) these pressures to the guard cell circuit.
Pressure P is exerted on the probe but is not registered by the
δ
D4719 − 20
methods used to prepare the test cavity shall cause the least
possible disturbance to the surrounding soil. Pressuremeter
testsinsoilmustbeperformedimmediatelyafterthetestcavity
is formed.
8.2 The preparation of a satisfactory borehole is the most
important step in obtaining an acceptable pressuremeter test.
An indication of the quality of the test cavity is given by the
magnitude of scatter of the test points and by the shape of the
pressuremetercurveobtained.Fig.4showsthetypicalshapeof
a pressuremeter curve obtained from a prebored test cavity.
Fig.5showsapressuremetercurveobtainedwhentheborehole
is too small or when the test is performed in a swelling soil.
Fig. 6 shows a cur
...