ASTM D6031/D6031M-96(2015)
(Test Method)Standard Test Method for Logging In Situ Moisture Content and Density of Soil and Rock by the Nuclear Method in Horizontal, Slanted, and Vertical Access Tubes
Standard Test Method for Logging In Situ Moisture Content and Density of Soil and Rock by the Nuclear Method in Horizontal, Slanted, and Vertical Access Tubes
SIGNIFICANCE AND USE
3.1 This test method is useful as a repeatable, nondestructive technique to monitor in-place density and moisture of soil and rock along lengthy sections of horizontal, slanted, and vertical access holes or tubes. With proper calibration in accordance with Annex A1, this test method can be used to quantify changes in density and moisture content of soil and rock.
3.2 This test method is used in vadose zone monitoring, for performance assessment of engineered barriers at waste facilities, and for research related to monitoring the movement of liquids (water solutions and hydrocarbons) through soil and rock. The nondestructive nature of the test allows repetitive measurements at a site and statistical analysis of results.
3.3 The fundamental assumptions inherent in this test method are that the dry bulk density of the test material is constant and that the response to fast neutrons and gammaray energy associated with soil and liquid chemistry is constant.
SCOPE
1.1 This test method covers collection and comparison of logs of thermalized-neutron counts and back-scattered gamma counts along horizontal or vertical air-filled access tubes.
1.2 The in situ water content in mass per unit volume and the density in mass per unit volume of soil and rock at positions or in intervals along the length of an access tube are calculated by comparing the thermal neutron count rate and gamma count rates respectively to previously established calibration data.
1.3 The values stated in either inch-pound units or SI units [presented in brackets] are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.3.1 The gravitational system of inch-pound units is used when dealing with inch-pound units. In this system, the pound (lbf) represents a unit of force (weight), while the unit for mass is slugs. The rationalized slug unit is not given, unless dynamic (F = ma) calculations are involved.
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 and health practices and determine the applicability of regulatory limitations prior to use. For specific hazards, see Section 6.
General Information
Relations
Buy Standard
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: D6031/D6031M − 96 (Reapproved 2015)
Standard Test Method for
Logging In Situ Moisture Content and Density of Soil and
Rock by the Nuclear Method in Horizontal, Slanted, and
Vertical Access Tubes
This standard is issued under the fixed designation D6031/D6031M; 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 D1586 Test Method for Penetration Test (SPT) and Split-
Barrel Sampling of Soils
1.1 This test method covers collection and comparison of
D1587 Practice for Thin-Walled Tube Sampling of Soils for
logs of thermalized-neutron counts and back-scattered gamma
Geotechnical Purposes
counts along horizontal or vertical air-filled access tubes.
D2113 Practice for Rock Core Drilling and Sampling of
1.2 The in situ water content in mass per unit volume and
Rock for Site Exploration
thedensityinmassperunitvolumeofsoilandrockatpositions
D2216 Test Methods for Laboratory Determination of Water
or in intervals along the length of an access tube are calculated
(Moisture) Content of Soil and Rock by Mass
by comparing the thermal neutron count rate and gamma count
D2922 Test Methods for Density of Soil and Soil-Aggregate
rates respectively to previously established calibration data.
in Place by Nuclear Methods (Shallow Depth) (With-
1.3 The values stated in either inch-pound units or SI units drawn 2007)
D2937 Test Method for Density of Soil in Place by the
[presented in brackets] are to be regarded separately as
standard. The values stated in each system may not be exact Drive-Cylinder Method
D3017 Test Method for Water Content of Soil and Rock in
equivalents;therefore,eachsystemshallbeusedindependently
of the other. Combining values from the two systems may Place by Nuclear Methods (Shallow Depth)
D3550 Practice for Thick Wall, Ring-Lined, Split Barrel,
result in non-conformance with the standard.
1.3.1 The gravitational system of inch-pound units is used Drive Sampling of Soils
D4428/D4428M Test Methods for Crosshole Seismic Test-
when dealing with inch-pound units. In this system, the pound
(lbf) represents a unit of force (weight), while the unit for mass ing
is slugs.The rationalized slug unit is not given, unless dynamic D4564 Test Method for Density and Unit Weight of Soil in
Place by the Sleeve Method (Withdrawn 2013)
(F = ma) calculations are involved.
D5195 Test Method for Density of Soil and Rock In-Place at
1.4 This standard does not purport to address all of the
Depths Below Surface by Nuclear Methods
safety concerns, if any, associated with its use. It is the
D5220 Test Method for Water Mass per Unit Volume of Soil
responsibility of the user of this standard to establish appro-
and Rock In-Place by the Neutron Depth Probe Method
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. For specific
3. Significance and Use
hazards, see Section 6.
3.1 This test method is useful as a repeatable, nondestruc-
2. Referenced Documents
tive technique to monitor in-place density and moisture of soil
and rock along lengthy sections of horizontal, slanted, and
2.1 ASTM Standards:
vertical access holes or tubes. With proper calibration in
D1452 Practice for Soil Exploration and Sampling byAuger
accordance with Annex A1, this test method can be used to
Borings
quantify changes in density and moisture content of soil and
rock.
Thistestmethodisunder the jurisdiction ofASTM CommitteeD18onSoiland
Rock and is the direct responsibility of Subcommittee D18.21 on Groundwater and
3.2 This test method is used in vadose zone monitoring, for
Vadose Zone Investigations.
performance assessment of engineered barriers at waste
Current edition approved Nov. 1, 2015. Published November 2015. Originally
ɛ1
facilities, and for research related to monitoring the movement
approved in 1996. Last previous edition approved in 2010 as D6031–96(2010) .
DOI: 10.1520/D6031_D6031M-96R15. of liquids (water solutions and hydrocarbons) through soil and
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6031/D6031M − 96 (2015)
rock. The nondestructive nature of the test allows repetitive 5.1.3 High-Energy Gamma-Radiation Source—A sealed
measurements at a site and statistical analysis of results. source of radioactive material, such as cesium-137, cobalt-60,
or radium-226.
3.3 The fundamental assumptions inherent in this test
5.1.4 Gamma Detector—Any type of gamma detector, such
method are that the dry bulk density of the test material is
as a Geiger-Mueller tube.
constant and that the response to fast neutrons and gammaray
energy associated with soil and liquid chemistry is constant. 5.1.5 Suitable Readout Device:
5.1.6 Cylindrical Probe—The apparatus shall be equipped
4. Interferences
with a cylindrical probe, containing the neutron and gamma
sources and the detectors, connected by a cable or cables of
4.1 The sample heterogeneity and chemical composition of
sufficient design and length, that are capable of raising and
the material under test will affect the measurement of both
lowering the probe in vertical applications and pulling it in
moisture and density.The apparatus should be calibrated to the
horizontal applications, to the desired measurement location.
material under test at a similar density of dry soil or rock and
5.1.7 Reference Standard—A device containing dense, hy-
in the similar type and orientation of access tube, or adjust-
drogenous material for checking equipment operation and to
ments must be made in accordance with Annex A2.
establish conditions for a reproducible reference count rate. It
4.2 Hydrogen, in forms other than water, as defined by Test
also may serve as a radiation shield.
Method D2216, will cause measurements in excess of the true
moisture content. Some elements such as boron, chlorine, and 5.2 Accessories shall include:
minute quantities of cadmium, if present in the material under
5.2.1 AccessTubing—The access tubing (casing) is required
test, will cause measurements lower than the true moisture
for all access holes in nonlithified materials (soils and poorly
content. Some elements with atomic numbers greater than 20
consolidated rock) that cannot maintain constant borehole
such as iron or other heavy metals may cause measurements
diameter with repeated measurements. If access tubing is
higher than the true density value.
required it must be of a material, such as aluminum, steel, or
plastic, having an interior diameter large enough to permit
4.3 The measurement of moisture and density using this test
probeaccesswithoutbinding,andanexteriordiameterassmall
method exhibits spatial bias in that it is more sensitive to the
as possible to provide close proximity of the material under
material closest to the access tube. The density and moisture
test. The same type of tubing must be used in the field as is
measurements are necessarily an average of the total sample
used in calibration.
involved.
5.2.2 Hand Auger or Power Drilling/Trenching
4.4 The sample volume for a moisture measurement is
Equipment—Equipmentthatcanbeusedtoestablishtheaccess
3 3
approximately 3.8 ft [0.11 m ] at a moisture content of 12.5
hole or position the access tube when required (see 5.2.1).Any
3 3
lbf/ft [200 kg/m ]. The actual sample volume for moisture is
equipment that provides a suitable clean open hole for instal-
indeterminate and varies with the apparatus and the moisture
lation of access tubing and insertion of the probe that ensures
content of the material. In general the greater the moisture
the measurements are performed on undisturbed soil and rock
content of the material, the smaller the measurement volume.
while maintaining a constant diameter per width shall be
4.5 Adensitymeasurementhasasamplevolumeofapproxi-
acceptable. The type of equipment and methods of advancing
3 3
mately 0.8 ft [0.028 m ]. The actual sample volume for
the access hole should be reported.
density is indeterminate and varies with the apparatus and the
5.2.3 Winching Equipment or Other Motive Devices—
densityofthematerial.Ingeneral,thegreaterthedensityofthe
Equipment that can be used to move the probe through the
material, the smaller the measurement volume.
access tubing. The type of such equipment is dependent upon
theorientationoftheaccesstubingandthedistanceoverwhich
4.6 Air gaps between the probe and the access tube or voids
the probe must be moved.
around the access tube will cause the indicated moisture
content and density to be less than the calibrated values.
6. Hazards
4.7 Condensed moisture inside the access tube may cause
the indicated moisture content to be greater than the true 6.1 Warning—This equipment utilizes radioactive materi-
moisture content of material outside the access tube.
als that may be hazardous to the health of the users unless
proper precautions are taken. Users of this equipment must
5. Apparatus become completely familiar with all possible safety hazards
andwithallapplicableregulationsconcerningthehandlingand
5.1 While exact details of construction of the apparatus may
use of radioactive materials. Effective user instructions to-
vary, the system shall consist of:
gether with routine safety procedures are a recommended part
5.1.1 Fast Neutron Source—A sealed mixture of a radioac-
of the operation of this apparatus.
tive material such as americium or radium and a target material
such as beryllium, or other fast neutron sources such as
6.2 Warning—When using winching or other motive
californium that do not require a target.
equipment, the user should take additional care to learn its
5.1.2 Slow Neutron Detector—Any type of slow neutron properuseinconjunctionwithmeasurementapparatus.Known
detector, such as boron trifluoride or helium-3 proportional safety hazards such as cutting and pinching exist when using
counters. such equipment.
D6031/D6031M − 96 (2015)
6.3 This test method does not cover all safety precautions. It 7.3.6 If the apparatus standardization has not been checked
is the responsibility of the users to familiarize themselves with within the previous three months, perform at lest four new
all safety precautions. standardization checks and use the mean as the value for No.
7.3.7 The value of Ns will be used to determine the count
7. Calibration, Standardization, and Reference Check ratios for the current day’s use of the equipment. If, for any
reason, either the measured density or moisture content be-
7.1 Calibrate the instrument in accordance with Annex A1.
come suspect during the day’s use, perform another standard-
7.2 Adjust the calibration in accordance with Annex A2 if ization to ensure that the equipment is stable.
adjustments are necessary.
8. Procedure
7.3 Standardization and Reference Check:
8.1 Installation of Access Tubing (Casing):
7.3.1 Nuclear apparatus are subject to the long-term decay
8.1.1 Drilltheaccessholeorexcavateatrenchatthedesired
of the radioactive source and aging of detectors and electronic
location and install the access tube in a manner to maximize
systems that may change the relationship between count rate
contactwithtestmaterialandminimizevoids.Theaccesstubes
and either the material density or the moisture content of the
should fit snugly into the access hole or trench. Unstable
material, or both. To correct for these changes, the apparatus
conditions in fill material around the access tube may result in
may be calibrated periodically. To minimize error, moisture
redistribution of solids over time, piping, or other phenomena
and density measurements commonly are reported as count
that will degrade precision. Voids caused during drilling, tube
ratios, the ratio of the measured count rate to a count rate made
installation,orbackfilling,oracombinationthereof,maycause
in a reference standard. The reference count rate should be
erroneously low results. Excessive compaction of clay-rich
similar or higher than the count rates over the useful measure-
backfill material will limit the effectiveness of moisture moni-
ment range of the apparatus.
toring for leak detection. Backfill should approximate the
7.3.2 Standardization of equipment on the reference stan-
composition, water content, and bulk density of test material as
dard is required at the start of each day’s use and a permanent
nearly as possible.
record of these data shall be retained.The standardization shall
8.1.2 Grouting of annular spaces, if required, should be of
be performed with the equipment located at least 33 ft [10 m]
minimum functional thickness, and grout mixtures should not
away from other radioactive sources and large masses or other
contain excessive water. Grouts thicker than 2 in. [5 cm] create
items that may affect the reference count rate.
high background counts that will obscure moisture content
7.3.3 If recommended by the apparatus manufacturer to
changes in fine-textured soils and severely limit meaningful
provide more stable and consistent results, turn on the appara-
density measurements in all soil types. Grouting should not be
tus prior to use to allow it to stabilize and leave the power on
used unless it is required to seal off flow pathways along the
during the day’s testing.
access tube, such as in some vertical borings and where
7.3.4 Using the reference standard, take at least four repeti-
trenches cross engineered barriers. Grouting can be accom-
tivereadingsatthemanufacturer’srecommendedmeasurement
plished using procedures described in Test Methods D4428/
period of 20 or more at some shorter period and obtain the
D4428M.
mean. If available on the instrument, one measurement at a
8.1.3 Record and note the position of the groundwater table,
period of four or more times the normal test measurement
perched water tables, and changes in soil texture as drilling or
period is acceptable. This constitutes one standardization
trenching progresses.
check.
8.1.4 If groundwater is encountered or saturated conditions
7.3.5 If the value obtained in 7.3.4 is within the following
are
...
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: D6031/D6031M − 96 (Reapproved 2015)
Standard Test Method for
Logging In Situ Moisture Content and Density of Soil and
Rock by the Nuclear Method in Horizontal, Slanted, and
Vertical Access Tubes
This standard is issued under the fixed designation D6031/D6031M; 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 D1586 Test Method for Penetration Test (SPT) and Split-
Barrel Sampling of Soils
1.1 This test method covers collection and comparison of
D1587 Practice for Thin-Walled Tube Sampling of Soils for
logs of thermalized-neutron counts and back-scattered gamma
Geotechnical Purposes
counts along horizontal or vertical air-filled access tubes.
D2113 Practice for Rock Core Drilling and Sampling of
1.2 The in situ water content in mass per unit volume and
Rock for Site Exploration
the density in mass per unit volume of soil and rock at positions
D2216 Test Methods for Laboratory Determination of Water
or in intervals along the length of an access tube are calculated
(Moisture) Content of Soil and Rock by Mass
by comparing the thermal neutron count rate and gamma count
D2922 Test Methods for Density of Soil and Soil-Aggregate
rates respectively to previously established calibration data.
in Place by Nuclear Methods (Shallow Depth) (With-
drawn 2007)
1.3 The values stated in either inch-pound units or SI units
[presented in brackets] are to be regarded separately as D2937 Test Method for Density of Soil in Place by the
Drive-Cylinder Method
standard. The values stated in each system may not be exact
equivalents; therefore, each system shall be used independently D3017 Test Method for Water Content of Soil and Rock in
Place by Nuclear Methods (Shallow Depth)
of the other. Combining values from the two systems may
result in non-conformance with the standard. D3550 Practice for Thick Wall, Ring-Lined, Split Barrel,
Drive Sampling of Soils
1.3.1 The gravitational system of inch-pound units is used
when dealing with inch-pound units. In this system, the pound D4428/D4428M Test Methods for Crosshole Seismic Test-
ing
(lbf) represents a unit of force (weight), while the unit for mass
D4564 Test Method for Density and Unit Weight of Soil in
is slugs. The rationalized slug unit is not given, unless dynamic
(F = ma) calculations are involved. Place by the Sleeve Method (Withdrawn 2013)
D5195 Test Method for Density of Soil and Rock In-Place at
1.4 This standard does not purport to address all of the
Depths Below Surface by Nuclear Methods
safety concerns, if any, associated with its use. It is the
D5220 Test Method for Water Mass per Unit Volume of Soil
responsibility of the user of this standard to establish appro-
and Rock In-Place by the Neutron Depth Probe Method
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. For specific
3. Significance and Use
hazards, see Section 6.
3.1 This test method is useful as a repeatable, nondestruc-
2. Referenced Documents
tive technique to monitor in-place density and moisture of soil
and rock along lengthy sections of horizontal, slanted, and
2.1 ASTM Standards:
vertical access holes or tubes. With proper calibration in
D1452 Practice for Soil Exploration and Sampling by Auger
accordance with Annex A1, this test method can be used to
Borings
quantify changes in density and moisture content of soil and
rock.
This test method is under the jurisdiction of ASTM Committee D18 on Soil and
Rock and is the direct responsibility of Subcommittee D18.21 on Groundwater and
3.2 This test method is used in vadose zone monitoring, for
Vadose Zone Investigations.
performance assessment of engineered barriers at waste
Current edition approved Nov. 1, 2015. Published November 2015. Originally
ɛ1 facilities, and for research related to monitoring the movement
approved in 1996. Last previous edition approved in 2010 as D6031–96(2010) .
DOI: 10.1520/D6031_D6031M-96R15. of liquids (water solutions and hydrocarbons) through soil and
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6031/D6031M − 96 (2015)
rock. The nondestructive nature of the test allows repetitive 5.1.3 High-Energy Gamma-Radiation Source—A sealed
measurements at a site and statistical analysis of results. source of radioactive material, such as cesium-137, cobalt-60,
or radium-226.
3.3 The fundamental assumptions inherent in this test
5.1.4 Gamma Detector—Any type of gamma detector, such
method are that the dry bulk density of the test material is
as a Geiger-Mueller tube.
constant and that the response to fast neutrons and gammaray
5.1.5 Suitable Readout Device:
energy associated with soil and liquid chemistry is constant.
5.1.6 Cylindrical Probe—The apparatus shall be equipped
4. Interferences
with a cylindrical probe, containing the neutron and gamma
sources and the detectors, connected by a cable or cables of
4.1 The sample heterogeneity and chemical composition of
sufficient design and length, that are capable of raising and
the material under test will affect the measurement of both
lowering the probe in vertical applications and pulling it in
moisture and density. The apparatus should be calibrated to the
horizontal applications, to the desired measurement location.
material under test at a similar density of dry soil or rock and
5.1.7 Reference Standard—A device containing dense, hy-
in the similar type and orientation of access tube, or adjust-
drogenous material for checking equipment operation and to
ments must be made in accordance with Annex A2.
establish conditions for a reproducible reference count rate. It
4.2 Hydrogen, in forms other than water, as defined by Test
also may serve as a radiation shield.
Method D2216, will cause measurements in excess of the true
moisture content. Some elements such as boron, chlorine, and 5.2 Accessories shall include:
minute quantities of cadmium, if present in the material under
5.2.1 Access Tubing—The access tubing (casing) is required
test, will cause measurements lower than the true moisture
for all access holes in nonlithified materials (soils and poorly
content. Some elements with atomic numbers greater than 20
consolidated rock) that cannot maintain constant borehole
such as iron or other heavy metals may cause measurements
diameter with repeated measurements. If access tubing is
higher than the true density value.
required it must be of a material, such as aluminum, steel, or
plastic, having an interior diameter large enough to permit
4.3 The measurement of moisture and density using this test
probe access without binding, and an exterior diameter as small
method exhibits spatial bias in that it is more sensitive to the
as possible to provide close proximity of the material under
material closest to the access tube. The density and moisture
test. The same type of tubing must be used in the field as is
measurements are necessarily an average of the total sample
used in calibration.
involved.
5.2.2 Hand Auger or Power Drilling/Trenching
4.4 The sample volume for a moisture measurement is
Equipment—Equipment that can be used to establish the access
3 3
approximately 3.8 ft [0.11 m ] at a moisture content of 12.5
hole or position the access tube when required (see 5.2.1). Any
3 3
lbf/ft [200 kg/m ]. The actual sample volume for moisture is
equipment that provides a suitable clean open hole for instal-
indeterminate and varies with the apparatus and the moisture
lation of access tubing and insertion of the probe that ensures
content of the material. In general the greater the moisture
the measurements are performed on undisturbed soil and rock
content of the material, the smaller the measurement volume.
while maintaining a constant diameter per width shall be
4.5 A density measurement has a sample volume of approxi-
acceptable. The type of equipment and methods of advancing
3 3
mately 0.8 ft [0.028 m ]. The actual sample volume for
the access hole should be reported.
density is indeterminate and varies with the apparatus and the
5.2.3 Winching Equipment or Other Motive Devices—
density of the material. In general, the greater the density of the
Equipment that can be used to move the probe through the
material, the smaller the measurement volume.
access tubing. The type of such equipment is dependent upon
the orientation of the access tubing and the distance over which
4.6 Air gaps between the probe and the access tube or voids
the probe must be moved.
around the access tube will cause the indicated moisture
content and density to be less than the calibrated values.
6. Hazards
4.7 Condensed moisture inside the access tube may cause
the indicated moisture content to be greater than the true
6.1 Warning—This equipment utilizes radioactive materi-
moisture content of material outside the access tube. als that may be hazardous to the health of the users unless
proper precautions are taken. Users of this equipment must
5. Apparatus become completely familiar with all possible safety hazards
and with all applicable regulations concerning the handling and
5.1 While exact details of construction of the apparatus may
use of radioactive materials. Effective user instructions to-
vary, the system shall consist of:
gether with routine safety procedures are a recommended part
5.1.1 Fast Neutron Source—A sealed mixture of a radioac-
of the operation of this apparatus.
tive material such as americium or radium and a target material
such as beryllium, or other fast neutron sources such as
6.2 Warning—When using winching or other motive
californium that do not require a target.
equipment, the user should take additional care to learn its
5.1.2 Slow Neutron Detector—Any type of slow neutron proper use in conjunction with measurement apparatus. Known
detector, such as boron trifluoride or helium-3 proportional safety hazards such as cutting and pinching exist when using
counters. such equipment.
D6031/D6031M − 96 (2015)
6.3 This test method does not cover all safety precautions. It 7.3.6 If the apparatus standardization has not been checked
is the responsibility of the users to familiarize themselves with within the previous three months, perform at lest four new
all safety precautions. standardization checks and use the mean as the value for No.
7.3.7 The value of Ns will be used to determine the count
7. Calibration, Standardization, and Reference Check ratios for the current day’s use of the equipment. If, for any
reason, either the measured density or moisture content be-
7.1 Calibrate the instrument in accordance with Annex A1.
come suspect during the day’s use, perform another standard-
7.2 Adjust the calibration in accordance with Annex A2 if ization to ensure that the equipment is stable.
adjustments are necessary.
8. Procedure
7.3 Standardization and Reference Check:
8.1 Installation of Access Tubing (Casing):
7.3.1 Nuclear apparatus are subject to the long-term decay
8.1.1 Drill the access hole or excavate a trench at the desired
of the radioactive source and aging of detectors and electronic
location and install the access tube in a manner to maximize
systems that may change the relationship between count rate
contact with test material and minimize voids. The access tubes
and either the material density or the moisture content of the
should fit snugly into the access hole or trench. Unstable
material, or both. To correct for these changes, the apparatus
conditions in fill material around the access tube may result in
may be calibrated periodically. To minimize error, moisture
redistribution of solids over time, piping, or other phenomena
and density measurements commonly are reported as count
that will degrade precision. Voids caused during drilling, tube
ratios, the ratio of the measured count rate to a count rate made
installation, or backfilling, or a combination thereof, may cause
in a reference standard. The reference count rate should be
erroneously low results. Excessive compaction of clay-rich
similar or higher than the count rates over the useful measure-
backfill material will limit the effectiveness of moisture moni-
ment range of the apparatus.
toring for leak detection. Backfill should approximate the
7.3.2 Standardization of equipment on the reference stan-
composition, water content, and bulk density of test material as
dard is required at the start of each day’s use and a permanent
nearly as possible.
record of these data shall be retained. The standardization shall
8.1.2 Grouting of annular spaces, if required, should be of
be performed with the equipment located at least 33 ft [10 m]
minimum functional thickness, and grout mixtures should not
away from other radioactive sources and large masses or other
contain excessive water. Grouts thicker than 2 in. [5 cm] create
items that may affect the reference count rate.
high background counts that will obscure moisture content
7.3.3 If recommended by the apparatus manufacturer to
changes in fine-textured soils and severely limit meaningful
provide more stable and consistent results, turn on the appara-
density measurements in all soil types. Grouting should not be
tus prior to use to allow it to stabilize and leave the power on
used unless it is required to seal off flow pathways along the
during the day’s testing.
access tube, such as in some vertical borings and where
7.3.4 Using the reference standard, take at least four repeti-
trenches cross engineered barriers. Grouting can be accom-
tive readings at the manufacturer’s recommended measurement
plished using procedures described in Test Methods D4428/
period of 20 or more at some shorter period and obtain the
D4428M.
mean. If available on the instrument, one measurement at a
8.1.3 Record and note the position of the groundwater table,
period of four or more times the normal test measurement
perched water tables, and changes in soil texture as drilling or
period is acceptable. This constitutes one standardization
trenching progresses.
check.
8.1.4 If groundwater is encountered or saturated conditions
7.3.5 If the value obtained in 7.3.4 is within the following
are expected to d
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´1
Designation: D6031/D6031M − 96 (Reapproved 2010) D6031/D6031M − 96 (Reapproved
2015)
Standard Test Method for
Logging In Situ Moisture Content and Density of Soil and
Rock by the Nuclear Method in Horizontal, Slanted, and
Vertical Access Tubes
This standard is issued under the fixed designation D6031/D6031M; 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.
ε NOTE—The units statement in 1.3 and the designation were revised editorially in August 2010.
1. Scope
1.1 This test method covers collection and comparison of logs of thermalized-neutron counts and back-scattered gamma counts
along horizontal or vertical air-filled access tubes.
1.2 The in situ water content in mass per unit volume and the density in mass per unit volume of soil and rock at positions or
in intervals along the length of an access tube are calculated by comparing the thermal neutron count rate and gamma count rates
respectively to previously established calibration data.
1.3 The values stated in either inch-pound units or SI units [presented in brackets] are to be regarded separately as standard.
The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other.
Combining values from the two systems may result in non-conformance with the standard.
1.3.1 The gravitational system of inch-pound units is used when dealing with inch-pound units. In this system, the pound (lbf)
represents a unit of force (weight), while the unit for mass is slugs. The rationalized slug unit is not given, unless dynamic (F =
ma) calculations are involved.
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 and health practices and determine the applicability of regulatory
limitations prior to use. For specific hazards, see Section 6.
2. Referenced Documents
2.1 ASTM Standards:
D1452 Practice for Soil Exploration and Sampling by Auger Borings
D1586 Test Method for Penetration Test (SPT) and Split-Barrel Sampling of Soils
D1587 Practice for Thin-Walled Tube Sampling of Soils for Geotechnical Purposes
D2113 Practice for Rock Core Drilling and Sampling of Rock for Site Exploration
D2216 Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass
D2922 Test Methods for Density of Soil and Soil-Aggregate in Place by Nuclear Methods (Shallow Depth) (Withdrawn 2007)
D2937 Test Method for Density of Soil in Place by the Drive-Cylinder Method
D3017 Test Method for Water Content of Soil and Rock in Place by Nuclear Methods (Shallow Depth)
D3550 Practice for Thick Wall, Ring-Lined, Split Barrel, Drive Sampling of Soils
D4428/D4428M Test Methods for Crosshole Seismic Testing
D4564 Test Method for Density and Unit Weight of Soil in Place by the Sleeve Method (Withdrawn 2013)
D5195 Test Method for Density of Soil and Rock In-Place at Depths Below Surface by Nuclear Methods
D5220 Test Method for Water Mass per Unit Volume of Soil and Rock In-Place by the Neutron Depth Probe Method
This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.21 on Groundwater and Vadose
Zone Investigations.
Current edition approved Aug. 1, 2010Nov. 1, 2015. Published September 2010November 2015. Originally approved in 1996. Last previous edition approved in 20042010
ɛ1
as D6031–96(2004).D6031–96(2010) . DOI: 10.1520/D6031_D6031M-96R10E01.10.1520/D6031_D6031M-96R15.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6031/D6031M − 96 (2015)
3. Significance and Use
3.1 This test method is useful as a repeatable, nondestructive technique to monitor in-place density and moisture of soil and rock
along lengthy sections of horizontal, slanted, and vertical access holes or tubes. With proper calibration in accordance with Annex
A1, this test method can be used to quantify changes in density and moisture content of soil and rock.
3.2 This test method is used in vadose zone monitoring, for performance assessment of engineered barriers at waste facilities,
and for research related to monitoring the movement of liquids (water solutions and hydrocarbons) through soil and rock. The
nondestructive nature of the test allows repetitive measurements at a site and statistical analysis of results.
3.3 The fundamental assumptions inherent in this test method are that the dry bulk density of the test material is constant and
that the response to fast neutrons and gammaray energy associated with soil and liquid chemistry is constant.
4. Interferences
4.1 The sample heterogeneity and chemical composition of the material under test will affect the measurement of both moisture
and density. The apparatus should be calibrated to the material under test at a similar density of dry soil or rock and in the similar
type and orientation of access tube, or adjustments must be made in accordance with Annex A2.
4.2 Hydrogen, in forms other than water, as defined by Test Method D2216, will cause measurements in excess of the true
moisture content. Some elements such as boron, chlorine, and minute quantities of cadmium, if present in the material under test,
will cause measurements lower than the true moisture content. Some elements with atomic numbers greater than 20 such as iron
or other heavy metals may cause measurements higher than the true density value.
4.3 The measurement of moisture and density using this test method exhibits spatial bias in that it is more sensitive to the
material closest to the access tube. The density and moisture measurements are necessarily an average of the total sample involved.
3 3 3
4.4 The sample volume for a moisture measurement is approximately 3.8 ft [0.11 m ] at a moisture content of 12.5 lbf/ft [200
kg/m ]. The actual sample volume for moisture is indeterminate and varies with the apparatus and the moisture content of the
material. In general the greater the moisture content of the material, the smaller the measurement volume.
3 3
4.5 A density measurement has a sample volume of approximately 0.8 ft [0.028 m ]. The actual sample volume for density is
indeterminate and varies with the apparatus and the density of the material. In general, the greater the density of the material, the
smaller the measurement volume.
4.6 Air gaps between the probe and the access tube or voids around the access tube will cause the indicated moisture content
and density to be less than the calibrated values.
4.7 Condensed moisture inside the access tube may cause the indicated moisture content to be greater than the true moisture
content of material outside the access tube.
5. Apparatus
5.1 While exact details of construction of the apparatus may vary, the system shall consist of:
5.1.1 Fast Neutron Source—A sealed mixture of a radioactive material such as americium or radium and a target material such
as beryllium, or other fast neutron sources such as californium that do not require a target.
5.1.2 Slow Neutron Detector—Any type of slow neutron detector, such as boron trifluoride or helium-3 proportional counters.
5.1.3 High-Energy Gamma-Radiation Source—A sealed source of radioactive material, such as cesium-137, cobalt-60, or
radium-226.
5.1.4 Gamma Detector—Any type of gamma detector, such as a Geiger-Mueller tube.
5.1.5 Suitable Readout Device:
5.1.6 Cylindrical Probe—The apparatus shall be equipped with a cylindrical probe, containing the neutron and gamma sources
and the detectors, connected by a cable or cables of sufficient design and length, that are capable of raising and lowering the probe
in vertical applications and pulling it in horizontal applications, to the desired measurement location.
5.1.7 Reference Standard—A device containing dense, hydrogenous material for checking equipment operation and to establish
conditions for a reproducible reference count rate. It also may serve as a radiation shield.
5.2 Accessories shall include:
5.2.1 Access Tubing—The access tubing (casing) is required for all access holes in nonlithified materials (soils and poorly
consolidated rock) that cannot maintain constant borehole diameter with repeated measurements. If access tubing is required it
must be of a material, such as aluminum, steel, or plastic, having an interior diameter large enough to permit probe access without
binding, and an exterior diameter as small as possible to provide close proximity of the material under test. The same type of tubing
must be used in the field as is used in calibration.
5.2.2 Hand Auger or Power Drilling/Trenching Equipment—Equipment that can be used to establish the access hole or position
the access tube when required (see 5.2.1). Any equipment that provides a suitable clean open hole for installation of access tubing
and insertion of the probe that ensures the measurements are performed on undisturbed soil and rock while maintaining a constant
diameter per width shall be acceptable. The type of equipment and methods of advancing the access hole should be reported.
D6031/D6031M − 96 (2015)
5.2.3 Winching Equipment or Other Motive Devices—Equipment that can be used to move the probe through the access tubing.
The type of such equipment is dependent upon the orientation of the access tubing and the distance over which the probe must
be moved.
6. Hazards
6.1 Warning—This equipment utilizes radioactive materials that may be hazardous to the health of the users unless proper
precautions are taken. Users of this equipment must become completely familiar with all possible safety hazards and with all
applicable regulations concerning the handling and use of radioactive materials. Effective user instructions together with routine
safety procedures are a recommended part of the operation of this apparatus.
6.2 Warning—When using winching or other motive equipment, the user should take additional care to learn its proper use in
conjunction with measurement apparatus. Known safety hazards such as cutting and pinching exist when using such equipment.
6.3 This test method does not cover all safety precautions. It is the responsibility of the users to familiarize themselves with all
safety precautions.
7. Calibration, Standardization, and Reference Check
7.1 Calibrate the instrument in accordance with Annex A1.
7.2 Adjust the calibration in accordance with Annex A2 if adjustments are necessary.
7.3 Standardization and Reference Check:
7.3.1 Nuclear apparatus are subject to the long-term decay of the radioactive source and aging of detectors and electronic
systems that may change the relationship between count rate and either the material density or the moisture content of the material,
or both. To correct for these changes, the apparatus may be calibrated periodically. To minimize error, moisture and density
measurements commonly are reported as count ratios, the ratio of the measured count rate to a count rate made in a reference
standard. The reference count rate should be similar or higher than the count rates over the useful measurement range of the
apparatus.
7.3.2 Standardization of equipment on the reference standard is required at the start of each day’s use and a permanent record
of these data shall be retained. The standardization shall be performed with the equipment located at least 33 ft [10 m] away from
other radioactive sources and large masses or other items that may affect the reference count rate.
7.3.3 If recommended by the apparatus manufacturer to provide more stable and consistent results, turn on the apparatus prior
to use to allow it to stabilize and leave the power on during the day’s testing.
7.3.4 Using the reference standard, take at least four repetitive readings at the manufacturer’s recommended measurement
period of 20 or more at some shorter period and obtain the mean. If available on the instrument, one measurement at a period of
four or more times the normal test measurement period is acceptable. This constitutes one standardization check.
7.3.5 If the value obtained in 7.3.4 is within the following limits, the equipment is considered to be in satisfactory condition
and the value may be used to determine the count ratios for the day of use. If the value obtained is outside these limits, another
standardization check should be made. If the second standardization check is within the limits, the equipment may be used. If it
also fails the test, however, the equipment shall be adjusted or repaired as recommended by the manufacturer.
No No
No12FŒ .Ns.No 2 2FŒ
F F
where:
Ns = value of current standardization check (7.3.4) on the reference standard,
No = average of the past values of Ns taken for prior usage, and
F = value of prescale, a multiplier that alters the count value for the purpose of display (see A3.1.1.1).
7.3.6 If the apparatus standardization has not been checked within the previous three months, perform at lest four new
standardization checks and use the mean as the value for No.
7.3.7 The value of Ns will be used to determine the count ratios for the current day’s use of the equipment. If, for any reason,
either the measured density or moisture content become suspect during the day’s use, perform another standardization to ensure
that the equipment is stable.
8. Procedure
8.1 Installation of Access Tubing (Casing):
8.1.1 Drill the access hole or excavate a trench at the desired location and install the access tube in a manner to maximize
contact with test material and minimize voids. The access tubes should fit snugly into the access hole or trench. Unstable conditions
in fill material around the access tube may result in redistribution of solids over time, piping, or other phenomena that will degrade
precision. Voids caused during drilling, tube in
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.