ASTM D5780-95(2002)
(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
SIGNIFICANCE AND USE
This test method will provide a relationship between time to failure, creep rate, and displacement to failure for specific failure loads at specific test temperatures as well as a relationship between creep rate and applied load at specific test temperatures for loads less than failure loads.
Pile design for specific soil temperatures may be controlled by either limiting long-term stress to below long-term strength or by limiting allowable settlement over the design life of the structure. It is the purpose of this test method to provide the basic information from which the limiting strength or long-term settlement may be evaluated by geotechnical engineers.
Data derived from pile tests at specific ground temperatures that differ from the design temperatures must be corrected to the design temperature by the use of data from additional pile tests, laboratory soil strength tests, or published correlations, if applicable, to provide a suitable means of correction.
For driven piles or grouted piles, failure will occur at the pile/soil interface. For slurried piles, failure can occur at either the pile/slurry interface or the slurry/soil interface, depending on the strength and deformation properties of the slurry material and the adfreeze bond strength. Location of the failure surface must be taken into account in the design of the test program and in the interpretation of the test results. Dynamic loads must be evaluated separately.
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: SectionReferenced Documents2 Terminology3 Significance and Use4 Installation of Test Piles5Apparatus for Applying Loads6Apparatus for Measuring Movements 7Safety Requirements8Loading Procedures9Standard Test Procedures10 Procedures for Measuring Pile Movements 11Report12 Precision and Bias13Keywords14
Note 1—Apparatus and procedures designated "optional" are to be required only when included in the project specifications or if not specified, may be used only with the approval of the engineer responsible for the foundation design. The word "shall" indicates a mandatory provision and "should" indicates a recommended or advisory provision. Imperative sentences indicate mandatory provisions. Notes, illustrations, and appendixes included herein are explanatory or advisory.
Note 2—This test method does not include the interpretation of test results or the application of test results to foundation design. See Appendix X1 for comments regarding some of the factors influencing the interpretation of test results. A qualified geotechnical engineer should interpret the test results for predicting pile performance and capacity.
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
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:D5780–95 (Reapproved 2002)
Standard Test Method for
Individual Piles in Permafrost Under Static Axial
Compressive Load
This standard is issued under the fixed designation D5780; 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.
INTRODUCTION
Thistestmethodhasbeenpreparedtocovermethodsofaxialloadtestingofpilesinpermafrost.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 1.2 The values stated in inch-pound units are to be regarded
as the standard. The SI units given in parentheses are for
1.1 This test method covers procedures for testing indi-
information only.
vidual vertical piles to determine response of the pile to static
1.3 This standard does not purport to address all of the
compressive load applied axially to the pile. This test method
safety concerns, if any, associated with its use. It is the
is applicable to all deep foundation units in permafrost that
responsibility of the user of this standard to establish appro-
functioninamannersimilartopilesregardlessoftheirmethod
priate safety and health practices and determine the applica-
of installation. This test method is divided into the following
bility of regulatory limitations prior to use. Specific precau-
sections:
tionary statements are given in Section 8.
Section
Referenced Documents 2
2. Referenced Documents
Terminology 3
Significance and Use 4 2
2.1 ASTM Standards:
Installation of Test Piles 5
D653 Terminology Relating to Soil, Rock, and Contained
Apparatus for Applying Loads 6
Apparatus for Measuring Movements 7
Fluids
Safety Requirements 8
2.2 ANSI Standard:
Loading Procedures 9
B30.1 Safety Code for Jacks
Standard Test Procedures 10
Procedures for Measuring Pile Movements 11
Report 12
3. Terminology
Precision and Bias 13
3.1 Definitions:
Keywords 14
3.1.1 Thestandarddefinitionsoftermsandsymbolsrelating
NOTE 1—Apparatus and procedures designated “optional” are to be
to soil and rock mechanics is Terminology D653.
required only when included in the project specifications or if not
3.2 Definitions of Terms Specific to This Standard:
specified, may be used only with the approval of the engineer responsible
for the foundation design. The word “shall” indicates a mandatory 3.2.1 adfreeze bond strength—the strength of the bond
provision and “should” indicates a recommended or advisory provision.
developed between frozen soil and the surface of the pile.
Imperative sentences indicate mandatory provisions. Notes, illustrations,
3.2.2 base load—a load equivalent to the design load
and appendixes included herein are explanatory or advisory.
adjusted for test pile geometry and expected ground tempera-
NOTE 2—This test method does not include the interpretation of test
ture.
results or the application of test results to foundation design. See
3.2.3 creep load—that load applied to measure a rate of
Appendix X1 for comments regarding some of the factors influencing the
displacement.
interpretation of test results. A qualified geotechnical engineer should
interpret the test results for predicting pile performance and capacity.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Rock and is the direct responsibility of Subcommittee D18.19 on Frozen Soils and Standards volume information, refer to the standard’s Document Summary page on
Rock. the ASTM website.
Current edition approved Sept. 10, 1995. Published January 1996. DOI: Available from American National Standards Institute, 25 W. 43rd St., 4th
10.1520/D5780-95R02. Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5780–95 (2002)
3.2.4 creep load increment—an incremental load applied to the pile/slurry interface or the slurry/soil interface, depending
apiletodeterminetherateofdisplacementat10%ofafailure on the strength and deformation properties of the slurry
load or at 100% of a design load. materialandtheadfreezebondstrength.Locationofthefailure
3.2.5 design active layer—the maximum depth of annual surface must be taken into account in the design of the test
thaw anticipated surrounding the pile under design conditions. program and in the interpretation of the test results. Dynamic
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,icecontent,andporewatersalinity,theengineermustensure
failure to occur. that adequate information is available for soil/ice conditions at the
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
theeffectsofendbearing,asopposedtotheshearresistanceon
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
vicesadjacenttothetestpiletodeterminethegroundtempera-
impact or vibratory pile hammer.
tureprofileadjacenttothepile.Measuregroundtemperaturein
3.2.13 pile, grouted—a pile placed in an oversized, pre-
frozengroundataminimumofthreelocationsalongthelength
drilled hole and backfilled with a sand, cement grout.
ofpile;forpileslongerthan10ft(3m),itisrecommendedthat
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—anytemperaturebelowthe
the exterior pile surface; for slurried piles, installation may be
actualfreezingtemperatureofthesoilwatercombinationbeing
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 bythecirculationofcoldairorliquidcoolant,discontinuesuch
time to failure, creep rate, and displacement to failure for coolingwhenthemeasuredgroundtemperaturesbecomeequal
specific failure loads at specific test temperatures as well as a to the desired ground temperature for the pile test; significant
relationshipbetweencreeprateandappliedloadatspecifictest 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
strengthorbylimitingallowablesettlementoverthedesignlife 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- beaccomplishedbyusingasleeveorcasing.Forslurriedpiles,
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
turesthatdifferfromthedesigntemperaturesmustbecorrected 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 Fordrivenpilesorgroutedpiles,failurewilloccuratthe 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
D5780–95 (2002)
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
TABLE 1 Minimum Delay Times (Days After Freezeback)
observation of the instrumentation.Where necessary, brace the
Delay Times, Days
Permafrost Ground Temperature,
unsupported length of the test pile(s) to prevent buckling
Condition − °F (°C)
Driven Piles Slurried Piles
without influencing the test results.
Ice-poor above 28 (−2) 10 14
5.8 If the top of the pile has been damaged during installa-
23 to 28 (−2 to − 5) 5 7
tion, remove the damaged portion prior to the test. below 23 (−5) 2 3
Ice-rich above 28 (−2) 14 20
NOTE 4—Consideration should be given to placing insulation on the
23 to 28 (−2 to − 5) 7 10
ground surface around the test pile in order to reduce the variation in below 23 (−5) 5 7
ground temperatures with time during the testing period. Where used,
ground surface insulation should be placed all around the test pile to a
distance of 5 ft (1.5 m), two times the depth of thawed soil or one third of
results, laboratory test results, or analytical results. Such other time
the installed pile length, whichever is greater. The effect of insulation at
intervalshallallowforthedissipationofnormalstressesdevelopeddueto
the surface should be taken into account in the design of production piles,
pile installation or freezeback, or both, to a level of 1% or less of their
which could be done analytically.
maximum value.
5.9 Allow the lateral normal stresses between the pile
6. Apparatus for Applying Loads
surface and the surrounding soil that develop during pile
6.1 General:
installation or freezeback, or both, to dissipate to a nominal
6.1.1 The apparatus for applying compressive loads to the
level prior to pile testing. For purposes of this test method, the
testpileshallbeasdescribedin6.3,6.4,or6.5,orasotherwise
delay time corresponding to the approximate test condition
specified and shall be constructed so that the loads are applied
from Table 1 shall be permitted to occur prior to commencing
tothecentrallongitudinalaxisofthepiletominimizeeccentric
load application to allow for the dissipation of normal stresses
loading. Subsections 6.3-6.5 are suitable for applying axial
on the pile shaft as discussed above.
loads to individual vertical piles.
NOTE 5—The engineer may direct that delay times other than those
shown in Table 1 be implemented, based on other completed pile test NOTE 6—Consideration should be given to providing sufficient clear
D5780–95 (2002)
spacebetweenthepilecapandthegroundsurfacetoeliminateanysupport
series of tests in a test program to provide an accuracy of less
of the cap by the soil. A properly constructed steel grillage may serve as
than 1% of the applied load. Calibrate the hydraulic jack(s)
an adequate pile cap for testing purposes.
over its complete range of ram travel for increasing and
6.1.2 For testing an individual pile, center a steel-bearing
decreasing applied loads at a temperature within the air
plate(s) on the pile and set perpendicular to the longitudinal temperaturerangeexpectedtooccurduringtheloadtest.Iftwo
axis of the pile. It shall be of sufficient thickness to prevent it
or more jacks are to be used to apply the test load, they shall
from bending under the loads involved (but not less than 2 in. beofthesameramdiameter,connectedtoacommonmanifold
(50 mm) thick). The size of the test plate shall be not less than
and pressure gage, and operated by a single hydraulic pump.
the size of the pile top nor less than the area covered by the
NOTE 7—Where tests will be carried out in subfreezing fluctuating air
base(s) of the hydraulic jack(s).
temperatures, it is recommended that thermal insulation be applied to the
6.1.3 For tests on precast or cast-in-place concrete piles, set
hydraulic jack, the hydraulic lines, and other components of the loading
the test plate, when used, in high-strength quick-setting grout.
system.
For
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.