ASTM D5780-95
(Test Method)Standard Test Method for Individual Piles in Permafrost Under Static Axial Compressive Load
Standard Test Method for Individual Piles in Permafrost Under Static Axial Compressive Load
SCOPE
1.1 This test method covers procedures for testing individual vertical piles to determine response of the pile to static compressive load applied axially to the pile. This test method is applicable to all deep foundation units in permafrost that function in a manner similar to piles regardless of their method of installation. This test method is divided into the following sections: Section Referenced Documents 2 Terminology 3 Significance and Use 4 Installation of Test Piles 5 Apparatus for Applying Loads 6 Apparatus for Measuring Movements 7 Safety Requirements 8 Loading Procedures 9 Standard Test Procedures 10 Procedures for Measuring Pile Movements 11 Report 12 Precision and Bias 13 Keywords 14
1.2 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only.
1.3 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. Specific precautionary statements are given in Section 8.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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Designation: D 5780 – 95
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Individual Piles in Permafrost Under Static Axial
Compressive Load
This standard is issued under the fixed designation D 5780; 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 (e) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
This test method has been prepared to cover methods of axial load testing of piles in permafrost. The
provisions permit the introduction of more detailed requirements and procedures when required to
satisfy the objectives of the test program. The procedures herein produce a relationship between
applied load and pile settlement for conditions of ground temperature at the time of test. The results
may be interpreted to establish long-term load capacity of piles in permafrost.
1. Scope as the standard. The SI units given in parentheses are for
information only.
1.1 This test method covers procedures for testing indi-
1.3 This standard does not purport to address all of the
vidual vertical piles to determine response of the pile to static
safety concerns, if any, associated with its use. It is the
compressive load applied axially to the pile. This test method
responsibility of the user of this standard to establish appro-
is applicable to all deep foundation units in permafrost that
priate safety and health practices and determine the applica-
function in a manner similar to piles regardless of their method
bility of regulatory limitations prior to use. Specific precau-
of installation. This test method is divided into the following
tionary statements are given in Section 8.
sections:
Section
2. Referenced Documents
Referenced Documents 2
Terminology 3
2.1 ASTM Standards:
Significance and Use 4
D 653 Terminology Relating to Soil, Rock, and Contained
Installation of Test Piles 5
Fluids
Apparatus for Applying Loads 6
Apparatus for Measuring Movements 7
2.2 ANSI Standard:
Safety Requirements 8
B 30.1 Safety Code for Jacks
Loading Procedures 9
Standard Test Procedures 10
3. Terminology
Procedures for Measuring Pile Movements 11
Report 12
3.1 Definitions:
Precision and Bias 13
3.1.1 The standard definitions of terms and symbols relating
Keywords 14
to soil and rock mechanics is Terminology D 653.
NOTE 1—Apparatus and procedures designated “optional” are to be
3.2 Definitions of Terms Specific to This Standard:
required only when included in the project specifications or if not
3.2.1 adfreeze bond strength—the strength of the bond
specified, may be used only with the approval of the engineer responsible
for the foundation design. The word “shall” indicates a mandatory developed between frozen soil and the surface of the pile.
provision and “should” indicates a recommended or advisory provision.
3.2.2 base load—a load equivalent to the design load
Imperative sentences indicate mandatory provisions. Notes, illustrations,
adjusted for test pile geometry and expected ground tempera-
and appendixes included herein are explanatory or advisory.
ture.
NOTE 2—This test method does not include the interpretation of test
3.2.3 creep load—that load applied to measure a rate of
results or the application of test results to foundation design. See
displacement.
Appendix X1 for comments regarding some of the factors influencing the
3.2.4 creep load increment—an incremental load applied to
interpretation of test results. A qualified geotechnical engineer should
interpret the test results for predicting pile performance and capacity. a pile to determine the rate of displacement at 10 % of a failure
load or at 100 % of a design load.
1.2 The values stated in inch-pound units are to be regarded
3.2.5 design active layer—the maximum depth of annual
thaw anticipated surrounding the pile under design conditions.
This test method is under the jurisdiction of ASTM Committee D-18 on Soil
and Rock and is the direct responsibility of Subcommittee D18.19 on Frozen Soils Annual Book of ASTM Standards, Vol 04.08.
and Rock. Available from American National Standards Institute, 11 W. 42nd St., 13th
Current edition approved Sept. 10, 1995. Published January 1996. Floor, New York, NY 10036.
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5780
3.2.6 failure (in piles)—pile displacement that is occurring loads must be evaluated separately.
at an increasing rate with time under the action of a constant
5. Installation of Test Pile(s)
load, incremental pile displacement that is increasing for
5.1 Install the test pile according to the procedures and
uniform time increments, or a creep rate which exceeds 100 %
specifications used for the installation of the production piles.
of the design creep rate when loaded to 100 % of the design
load.
NOTE 3—Because the pile behavior will be influenced by the soil type,
3.2.7 failure load—that load applied to a pile to cause
temperature, ice content, and pore water salinity, the engineer must ensure
that adequate information is available for soil/ice conditions at the
failure to occur.
construction site to determine their effect on the pile performance (that is,
3.2.8 failure load increment—the load increment applied to
test pile should be installed in the same condition as the production
a pile that causes failure within a specified time period.
piles—preferably at the same site).
3.2.9 freezeback—for the purpose of this test method, free-
5.2 The design and installation of the test pile shall address
zeback shall be defined as the attainment of a subfreezing
the effects of end bearing, as opposed to the shear resistance on
temperature at each ground temperature measuring point lo-
the shaft of the pile. Address end bearing by measuring its
cated below the design active layer, which have attained
effect, eliminating its effect, or accounting for its effect
equilibrium with the surrounding soil.
analytically. Measure end bearing by attaching a load cell to
3.2.10 ice-poor—frozen soil with a high solids concentra-
the tip of the pile prior to installation or by attaching a series
tion whose behavior is characterized mainly by soil particle
of strain gages along the length of the pile prior to installation.
contacts.
Eliminate end bearing by attaching a compressible layer to the
3.2.11 ice-rich—frozen soil with a moderate to low solids
tip of the pile prior to installation or by providing a void
concentration whose behavior is characterized by ice particle
beneath the tip of the pile.
contacts.
5.3 Install thermistors or other temperature-measuring de-
3.2.12 pile, driven—a pile driven into the ground with an
vices adjacent to the test pile to determine the ground tempera-
impact or vibratory pile hammer.
ture profile adjacent to the pile. Measure ground temperature in
3.2.13 pile, grouted—a pile placed in an oversized, pre-
frozen ground at a minimum of three locations along the length
drilled hole and backfilled with a sand, cement grout.
of pile; for piles longer than 10 ft (3 m), it is recommended that
3.2.14 pile, slurried—a pile placed in an oversized, pre-
ground temperatures be measured at 5-ft (1.5-m) depth inter-
drilled hole and backfilled with a soil/water slurry.
vals. Install the temperature-measuring devices in contact with
3.2.15 subfreezing temperature—any temperature below the
the exterior pile surface; for slurried piles, installation may be
actual freezing temperature of the soil water combination being
as shown in Fig. 1; for driven piles, installation may be as
used.
shown in Fig. 2.
3.2.16 time to failure—the total time from the start of the
5.4 Measure ground temperatures periodically using the
current test load increment to the point at which failure begins
installed temperature-measuring devices to determine when
to occur.
freezeback occurs.
4. Significance and Use
5.5 Where freezeback of soils adjacent to the pile is aided
4.1 This test method will provide a relationship between by the circulation of cold air or liquid coolant, discontinue such
time to failure, creep rate, and displacement to failure for cooling when the measured ground temperatures become equal
specific failure loads at specific test temperatures as well as a to the desired ground temperature for the pile test; significant
relationship between creep rate and applied load at specific test overcooling shall not be permitted to occur. When freezeback
temperatures for loads less than failure loads. of soils adjacent to the test piles is aided by a designed cooling
4.2 Pile design for specific soil temperatures may be con- system, such designed cooling system shall also be applied in
trolled by either limiting long-term stress to below long-term a similar manner to all reaction piles to ensure freezeback of
strength or by limiting allowable settlement over the design life the reaction piles.
of the structure. It is the purpose of this test method to provide 5.6 Isolate the surface of the test pile from the surrounding
the basic information from which the limiting strength or soil or ice over the depth of the design active layer. This may
long-term settlement may be evaluated by geotechnical engi- be accomplished by using a sleeve or casing. For slurried piles,
neers. a greased wrapping or other technique that will essentially
4.3 Data derived from pile tests at specific ground tempera- eliminate the transfer of shear forces between the pile and the
tures that differ from the design temperatures must be corrected surrounding soil/ice in the design active layer may be used.
to the design temperature by the use of data from additional 5.7 Where feasible, excavate the immediate area of the test
pile tests, laboratory soil strength tests, or published correla- pile or fill to the proposed finished grade elevation. Cut off test
tions, if applicable, to provide a suitable means of correction. piles or build up to the proper grade necessary to permit
4.4 For driven piles or grouted piles, failure will occur at the construction of the load-application apparatus, placement of
pile/soil interface. For slurried piles, failure can occur at either the necessary testing and instrumentation equipment, and
the pile/slurry interface or the slurry/soil interface, depending observation of the instrumentation. Where necessary, brace the
on the strength and deformation properties of the slurry unsupported length of the test pile(s) to prevent buckling
material and the adfreeze bond strength. Location of the failure without influencing the test results.
surface must be taken into account in the design of the test 5.8 If the top of the pile has been damaged during installa-
program and in the interpretation of the test results. Dynamic tion, remove the damaged portion prior to the test.
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5780
FIG. 2 Potential Placement of Temperature Measuring Devices for
FIG. 1 Placement of Temperature Measuring Devices for Slurried
Driven Structural-Shaped Test Pile
Test Pile
NOTE 4—Consideration should be given to placing insulation on the
6.1.1 The apparatus for applying compressive loads to the
ground surface around the test pile in order to reduce the variation in
test pile shall be as described in 6.3, 6.4, or 6.5, or as otherwise
ground temperatures with time during the testing period. Where used,
specified and shall be constructed so that the loads are applied
ground surface insulation should be placed all around the test pile to a
to the central longitudinal axis of the pile to minimize eccentric
distance of 5 ft (1.5 m), two times the depth of thawed soil or one third of
loading. Subsections 6.3-6.5 are suitable for applying axial
the installed pile length, whichever is greater. The effect of insulation at
the surface should be taken into account in the design of production piles, loads to individual vertical piles.
which could be done analytically.
NOTE 6—Consideration should be given to providing sufficient clear
5.9 Allow the lateral normal stresses between the pile
space between the pile cap and the ground surface to eliminate any support
surface and the surrounding soil that develop during pile of the cap by the soil. A properly constructed steel grillage may serve as
an adequate pile cap for testing purposes.
installation or freezeback, or both, to dissipate to a nominal
level prior to pile testing. For purposes of this test method, the
6.1.2 For testing an individual pile, center a steel-bearing
delay time corresponding to the approximate test condition
plate(s) on the pile and set perpendicular to the longitudinal
from Table 1 shall be permitted to occur prior to commencing
axis of the pile. It shall be of sufficient thickness to prevent it
load application to allow for the dissipation of normal stresses
from bending under the loads involved (but not less than 2 in.
on the pile shaft as discussed above.
TABLE 1 Minimum Delay Times (Days After Freezeback)
NOTE 5—The engineer may direct that delay times other than those
shown in Table 1 be implemented, based on other completed pile test Delay Times, Days
Permafrost Ground Temperature,
results, laboratory test results, or analytical results. Such other time
Condition − °F (°C)
Driven Piles Slurried Piles
interval shall allow for the dissipation of normal stresses developed due to
Ice-poor above 28 (−2) 10 14
pile installation or freezeback, or both, to a level of 1 % or less of their
23 to 28 (−2 to − 5) 5 7
maximum value.
below 23 (−5) 2 3
Ice-rich above 28 (−2) 14 20
6. Apparatus for Applying Loads
23 to 28 (−2 to − 5) 7 10
below 23 (−5) 5 7
6.1 General:
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5780
NOTE 7—Where tests will be carried out in subfreezing fluctuating air
(50 mm) thick). The size of the test plate shall be not less than
temperatures, it is recommended that thermal insulation be applied to the
the size of the pile top nor less than the area covered by the
hydraulic jack, the hydraulic lines, and other components of the loading
base(s) of the hydraulic jack(s).
system.
6.1.3 For tests on precast or cast-in-place concrete piles
...
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