Standard Test Method for Determination of Thermal Conductivity of Soil and Soft Rock by Thermal Needle Probe Procedure

SCOPE
1.1 This test method presents a procedure for determining the thermal conductivity of soil and soft rock using a transient heat method. This test method is applicable for both undisturbed and remolded soil specimens as well as in situ and laboratory soft rock specimens. This test method is suitable only for isotropic materials.
1.2 This test method is applicable to dry materials over the temperature range from 20 to 100°C. It may be used over a limited range around ambient room temperatures for specimens containing moisture.
1.3 For satisfactory results in conformance with this test method, the principles governing the size, construction, and use of the apparatus described in this test method should be followed. If the results are to be reported as having been obtained by this test method, then all pertinent requirements prescribed in this test method shall be met.
1.4 It is not practicable in a test method of this type to aim to establish details of construction and procedure to cover all contingencies that might offer difficulties to a person without technical knowledge concerning the theory of heat flow, temperature measurement, and general testing practices. Standardization of this test method does not reduce the need for such technical knowledge. It is recognized also that it would be unwise, because of the standardization of this test method, to resist in any way the further development of improved or new methods or procedures by research workers.
1.5 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.
1.6 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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ASTM D5334-00(2004) - Standard Test Method for Determination of Thermal Conductivity of Soil and Soft Rock by Thermal Needle Probe Procedure
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D5334–00 (Reapproved 2004)
Standard Test Method for
Determination of Thermal Conductivity of Soil and Soft
Rock by Thermal Needle Probe Procedure
This standard is issued under the fixed designation D 5334; 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.
1. Scope 2. Referenced Documents
1.1 This test method presents a procedure for determining 2.1 ASTM Standards:
the thermal conductivity of soil and soft rock using a transient D 2216 TestMethodforLaboratoryDeterminationofWater
heat method. This test method is applicable for both undis- (Moisture) Content of Soil and Rock
turbed and remolded soil specimens as well as in situ and D 4439 Terminology for Geotextiles
laboratory soft rock specimens. This test method is suitable
3. Terminology
only for isotropic materials.
1.2 This test method is applicable to dry materials over the 3.1 Definitions of Terms Specific to This Standard:
3.1.1 thermalepoxy—anythermallyconductivefilledepoxy
temperature range from 20 to 100°C. It may be used over a
limitedrangearoundambientroomtemperaturesforspecimens material having a value of l > 4 W/(m·k).
3.1.2 thermal grease—any thermally conductivity grease
containing moisture.
1.3 For satisfactory results in conformance with this test having a value of l > 4 W/(m·k).
3.2 Symbols:
method, the principles governing the size, construction, and
use of the apparatus described in this test method should be 3.2.1 E—measured voltage (V).
3.2.2 I—current flowing through heater wire (A).
followed. If the results are to be reported as having been
obtained by this test method, then all pertinent requirements 3.2.3 L—length of heater wire (m).
3.2.4 l—thermal conductivity [W/(m·k)].
prescribed in this test method shall be met.
1.4 It is not practicable in a test method of this type to aim 3.2.5 Q—power consumption of heater wire in watts per
unit length that is assumed to be the equivalent of heat output
to establish details of construction and procedure to cover all
per unit length of wire.
contingencies that might offer difficulties to a person without
technical knowledge concerning the theory of heat flow, 3.2.6 R—total resistance of heater wire (V).
3.2.7 T —initial temperature (k).
temperature measurement, and general testing practices. Stan-
dardization of this test method does not reduce the need for 3.2.8 t —initial time (s).
3.2.9 T —final temperature (k).
suchtechnicalknowledge.Itisrecognizedalsothatitwouldbe
unwise, because of the standardization of this test method, to 3.2.10 t —final time (s).
3.2.11 p —dry density (kg/m ).
resist in any way the further development of improved or new
d
methods or procedures by research workers.
4. Summary of Test Method
1.5 The values stated in SI units are to be regarded as the
4.1 The thermal conductivity is determined by a variation of
standard. The inch-pound units given in parentheses are for
the line source test method using a needle probe having a large
information only.
length to diameter ratio to stimulate conditions for an infinitely
1.6 This standard does not purport to address all of the
long specimen. The probe consists of a heating element and a
safety concerns, if any, associated with its use. It is the
temperature measuring element and is inserted into the speci-
responsibility of the user of this standard to establish appro-
men. A known current and voltage is applied to the probe and
priate safety and health practices and determine the applica-
the temperature rise with time noted over a period of time. The
bility of regulatory limitations prior to use.
1 2
ThistestmethodisunderthejurisdictionofASTMCommitteeD18onSoiland For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Rock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Nov. 1, 2004. Published December 2004. Originally Standards volume information, refer to the standard’s Document Summary page on
approved in 1992. Last previous edition approved in 2000 as D 5334 – 00. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5334–00 (2004)
thermal conductivity is obtained from an analysis of the ductivity, refer to Mitchell et al. (1). The tube should have a
approximately linear portion of the quasi-steady-state minimum diameter of 51 mm (2.0 in.) and a length of 200 6
temperature-time response. 30 mm (8.0 6 1 in.).
7.2.2 Perform 7.1.2 and 7.1.3.
7.3 Soft Rock Specimens:
5. Significance and Use
7.3.1 Specimendimensionsshallbenolessthanthoseofthe
5.1 The thermal conductivity of both undisturbed and re-
calibration standard (8.3).
molded soil specimens as well as in situ and laboratory soft
7.3.2 Insert the thermal needle probe into the specimen by
rock specimens is used to analyze and design systems used, for
predrilling a hole to a depth equal to the length of the probe.
example, in underground transmission lines, oil and gas pipe-
(See Note 1.)
lines, radioactive waste disposal, and solar thermal storage
facilities.
8. Calibration
8.1 Thethermalneedleprobeapparatusshouldbecalibrated
6. Apparatus
before its use. Perform calibration by comparing the experi-
6.1 The apparatus shall consist of the following:
mental determination of the thermal conductivity of a standard
6.1.1 Thermal Needle Probe—Adevice that creates a linear
material to its known value.
heat source and incorporates a temperature measuring element
8.2 Conduct the test specified in Section 9 using a calibra-
(thermocouple or thermistor) to measure the variation of
tion standard as specified in 8.3.
temperature at a point along the line. The construction of a
8.3 Calibration Standard—One or more materials with
suitable device is described in Annex A1.
known values of thermal conductivity in the range of the
6.1.2 Constant Current Source—A device to produce a
materials being measured (typically 0.2 < l < 5 W/m·K).
constant current.
Suitable materials include dry Ottawa sand, Pyrex 7740, Fused
6.1.3 Thermal Readout Unit—Adevice to produce a digital
Silica and Pryoceram 9606 (2). The calibration standard shall
readout of temperature in degrees Celsius to the nearest 0.1C.
be in the shape of a cylinder.The diameter of the cylinder shall
6.1.4 Voltage-Ohm-Meter (VOM)—Adevice to read voltage
be at least 40 mm and the length shall be at least 10 cm longer
and current to the nearest 0.01 V and ampere.
than the needle probe.Ahole shall be drilled along the axis of
6.1.5 Timer, stopwatch or similar time measuring instru-
the cylinder to a depth equal to the length of the probe. The
ment capable of measuring to the nearest 0.1 s for a minimum
diameter of the hole shall be equal to the diameter of the probe
of 15 min.
so that the probe fits tightly into the hole.
6.1.6 Equipment, capable of drilling a straight vertical hole
8.4 The measured thermal conductivity of the calibration
having a diameter as close as possible to that of the probe and
specimen must agree within one standard deviation of the
to a depth at least equal to the length of the needle.
published value of thermal conductivity, or with the value of
thermal conductivity determined by an independent method.
7. Specimen Preparation
9. Procedure
7.1 Undisturbed Specimens:
9.1 For tests conducted in the laboratory, allow the speci-
7.1.1 Thin-Walled Tube or Drive Specimens—Cut a 200 6
men to come to equilibrium with room temperature.
30-mm(8.0 61-in.)longsectionofasamplingtubecontaining
9.2 Connect the heater wire of the thermal probe to the
an undisturbed soil specimen. The tube section should have a
constant current source. (See Fig. 1.)
minimum diameter of 51 mm (2.0 in.).
9.3 Connect the temperature measuring element leads to the
7.1.2 Weigh the specimen in a sampling tube or brass rings.
readout unit.
7.1.3 Insert the thermal needle probe into the specimen by
either pushing the probe into a predrilled hole (dense speci-
men) to a depth equal to the length of the probe or pushing the
probe into the specimen (loose specimen). Care should be
The boldface numbers given in parentheses refer to a list of references at the
taken to ensure that the thermal probe shaft is fully
...

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