1、Designation: D6031/D6031M 96 (Reapproved 2010)1Standard Test Method forLogging In Situ Moisture Content and Density of Soil andRock by the Nuclear Method in Horizontal, Slanted, andVertical Access Tubes1This standard is issued under the fixed designation D6031/D6031M; the number immediately followin
2、g the designation indicates theyear of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEThe units statement in 1.3
3、and the designation were revised editorially in August 2010.1. Scope1.1 This test method covers collection and comparison oflogs of thermalized-neutron counts and back-scattered gammacounts along horizontal or vertical air-filled access tubes.1.2 The in situ water content in mass per unit volume and
4、the density in mass per unit volume of soil and rock at positionsor in intervals along the length of an access tube are calculatedby comparing the thermal neutron count rate and gamma countrates respectively to previously established calibration data.1.3 The values stated in either inch-pound units
5、or SI unitspresented in brackets are to be regarded separately asstandard. The values stated in each system may not be exactequivalents; therefore, each system shall be used independentlyof the other. Combining values from the two systems mayresult in non-conformance with the standard.1.3.1 The grav
6、itational system of inch-pound units is usedwhen dealing with inch-pound units. In this system, the pound(lbf) represents a unit of force (weight), while the unit for massis slugs. The rationalized slug unit is not given, unless dynamic(F = ma) calculations are involved.1.4 This standard does not pu
7、rport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specifichazards, see Section 6.2. Refer
8、enced Documents2.1 ASTM Standards:2D1452 Practice for Soil Exploration and Sampling byAugerBoringsD1586 Test Method for Penetration Test (SPT) and Split-Barrel Sampling of SoilsD1587 Practice for Thin-Walled Tube Sampling of Soils forGeotechnical PurposesD2113 Practice for Rock Core Drilling and Sam
9、pling ofRock for Site InvestigationD2216 Test Methods for Laboratory Determination of Wa-ter (Moisture) Content of Soil and Rock by MassD2922 Test Methods for Density of Soil and Soil-Aggregatein Place by Nuclear Methods (Shallow Depth)3D2937 Test Method for Density of Soil in Place by theDrive-Cyli
10、nder MethodD3017 Test Method for Water Content of Soil and Rock inPlace by Nuclear Methods (Shallow Depth)D3550 Practice for Thick Wall, Ring-Lined, Split Barrel,Drive Sampling of SoilsD4428/D4428M Test Methods for Crosshole Seismic Test-ingD4564 Test Method for Density and Unit Weight of Soil inPla
11、ce by the Sleeve MethodD5195 Test Method for Density of Soil and Rock In-Placeat Depths Below Surface by Nuclear MethodsD5220 Test Method for Water Mass per Unit Volume of Soiland Rock In-Place by the Neutron Depth Probe Method3. Significance and Use3.1 This test method is useful as a repeatable, no
12、ndestruc-tive technique to monitor in-place density and moisture of soiland rock along lengthy sections of horizontal, slanted, andvertical access holes or tubes. With proper calibration inaccordance with Annex A1, this test method can be used toquantify changes in density and moisture content of so
13、il androck.3.2 This test method is used in vadose zone monitoring, forperformance assessment of engineered barriers at waste facili-ties, and for research related to monitoring the movement ofliquids (water solutions and hydrocarbons) through soil and1This test method is under the jurisdiction ofAST
14、M Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.21 on Ground Water andVadose Zone Investigations.Current edition approved Aug. 1, 2010. Published September 2010. Originallyapproved in 1996. Last previous edition approved in 2004 as D603196(2004).DOI: 10.1520/D603
15、1_D6031M-96R10E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of th
16、is historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.rock. The nondestructive nature of the test allows repetitivemeasurements at a site and statistical analysis of results.3.3 The funda
17、mental assumptions inherent in this testmethod are that the dry bulk density of the test material isconstant and that the response to fast neutrons and gammarayenergy associated with soil and liquid chemistry is constant.4. Interferences4.1 The sample heterogeneity and chemical composition ofthe mat
18、erial under test will affect the measurement of bothmoisture and density. The apparatus should be calibrated to thematerial under test at a similar density of dry soil or rock andin the similar type and orientation of access tube, or adjust-ments must be made in accordance with Annex A2.4.2 Hydrogen
19、, in forms other than water, as defined by TestMethod D2216, will cause measurements in excess of the truemoisture content. Some elements such as boron, chlorine, andminute quantities of cadmium, if present in the material undertest, will cause measurements lower than the true moisturecontent. Some
20、elements with atomic numbers greater than 20such as iron or other heavy metals may cause measurementshigher than the true density value.4.3 The measurement of moisture and density using this testmethod exhibits spatial bias in that it is more sensitive to thematerial closest to the access tube. The
21、density and moisturemeasurements are necessarily an average of the total sampleinvolved.4.4 The sample volume for a moisture measurement isapproximately 3.8 ft30.11 m3 at a moisture content of 12.5lbf/ft3200 kg/m3. The actual sample volume for moisture isindeterminate and varies with the apparatus a
22、nd the moisturecontent of the material. In general the greater the moisturecontent of the material, the smaller the measurement volume.4.5 Adensity measurement has a sample volume of approxi-mately 0.8 ft30.028 m3. The actual sample volume fordensity is indeterminate and varies with the apparatus an
23、d thedensity of the material. In general, the greater the density of thematerial, the smaller the measurement volume.4.6 Air gaps between the probe and the access tube or voidsaround the access tube will cause the indicated moisturecontent and density to be less than the calibrated values.4.7 Conden
24、sed moisture inside the access tube may causethe indicated moisture content to be greater than the truemoisture content of material outside the access tube.5. Apparatus5.1 While exact details of construction of the apparatus mayvary, the system shall consist of:5.1.1 Fast Neutron SourceA sealed mixt
25、ure of a radioac-tive material such as americium or radium and a target materialsuch as beryllium, or other fast neutron sources such ascalifornium that do not require a target.5.1.2 Slow Neutron DetectorAny type of slow neutrondetector, such as boron trifluoride or helium-3 proportionalcounters.5.1
26、.3 High-Energy Gamma-Radiation Source A sealedsource of radioactive material, such as cesium-137, cobalt-60,or radium-226.5.1.4 Gamma DetectorAny type of gamma detector, suchas a Geiger-Mueller tube.5.1.5 Suitable Readout Device:5.1.6 Cylindrical ProbeThe apparatus shall be equippedwith a cylindrica
27、l probe, containing the neutron and gammasources and the detectors, connected by a cable or cables ofsufficient design and length, that are capable of raising andlowering the probe in vertical applications and pulling it inhorizontal applications, to the desired measurement location.5.1.7 Reference
28、StandardA device containing dense, hy-drogenous material for checking equipment operation and toestablish conditions for a reproducible reference count rate. Italso may serve as a radiation shield.5.2 Accessories shall include:5.2.1 Access TubingThe access tubing (casing) is requiredfor all access h
29、oles in nonlithified materials (soils and poorlyconsolidated rock) that cannot maintain constant boreholediameter with repeated measurements. If access tubing isrequired it must be of a material, such as aluminum, steel, orplastic, having an interior diameter large enough to permitprobe access witho
30、ut binding, and an exterior diameter as smallas possible to provide close proximity of the material undertest. The same type of tubing must be used in the field as isused in calibration.5.2.2 Hand Auger or Power Drilling/TrenchingEquipmentEquipment that can be used to establish the accesshole or pos
31、ition the access tube when required (see 5.2.1). Anyequipment that provides a suitable clean open hole for instal-lation of access tubing and insertion of the probe that ensuresthe measurements are performed on undisturbed soil and rockwhile maintaining a constant diameter per width shall beacceptab
32、le. The type of equipment and methods of advancingthe access hole should be reported.5.2.3 Winching Equipment or Other Motive DevicesEquipment that can be used to move the probe through theaccess tubing. The type of such equipment is dependent uponthe orientation of the access tubing and the distanc
33、e over whichthe probe must be moved.6. Hazards6.1 WarningThis equipment utilizes radioactive materi-als that may be hazardous to the health of the users unlessproper precautions are taken. Users of this equipment mustbecome completely familiar with all possible safety hazardsand with all applicable
34、regulations concerning the handling anduse of radioactive materials. Effective user instructions to-gether with routine safety procedures are a recommended partof the operation of this apparatus.6.2 WarningWhen using winching or other motiveequipment, the user should take additional care to learn it
35、sproper use in conjunction with measurement apparatus. Knownsafety hazards such as cutting and pinching exist when usingsuch equipment.6.3 This test method does not cover all safety precautions. Itis the responsibility of the users to familiarize themselves withall safety precautions.7. Calibration,
36、 Standardization, and Reference Check7.1 Calibrate the instrument in accordance with Annex A1.D6031/D6031M 96 (2010)127.2 Adjust the calibration in accordance with Annex A2 ifadjustments are necessary.7.3 Standardization and Reference Check:7.3.1 Nuclear apparatus are subject to the long-term decayo
37、f the radioactive source and aging of detectors and electronicsystems that may change the relationship between count rateand either the material density or the moisture content of thematerial, or both. To correct for these changes, the apparatusmay be calibrated periodically. To minimize error, mois
38、tureand density measurements commonly are reported as countratios, the ratio of the measured count rate to a count rate madein a reference standard. The reference count rate should besimilar or higher than the count rates over the useful measure-ment range of the apparatus.7.3.2 Standardization of e
39、quipment on the reference stan-dard is required at the start of each days use and a permanentrecord of these data shall be retained. The standardization shallbe performed with the equipment located at least 33 ft 10 maway from other radioactive sources and large masses or otheritems that may affect
40、the reference count rate.7.3.3 If recommended by the apparatus manufacturer toprovide more stable and consistent results, turn on the appara-tus prior to use to allow it to stabilize and leave the power onduring the days testing.7.3.4 Using the reference standard, take at least four repeti-tive read
41、ings at the manufacturers recommended measurementperiod of 20 or more at some shorter period and obtain themean. If available on the instrument, one measurement at aperiod of four or more times the normal test measurementperiod is acceptable. This constitutes one standardizationcheck.7.3.5 If the va
42、lue obtained in 7.3.4 is within the followinglimits, the equipment is considered to be in satisfactorycondition and the value may be used to determine the countratios for the day of use. If the value obtained is outside theselimits, another standardization check should be made. If thesecond standard
43、ization check is within the limits, the equip-ment may be used. If it also fails the test, however, theequipment shall be adjusted or repaired as recommended by themanufacturer.No 1 2FNoF. Ns . No 2 2FNoFwhere:Ns = value of current standardization check (7.3.4)onthereference standard,No = average of
44、 the past values of Ns taken for priorusage, andF = value of prescale, a multiplier that alters the countvalue for the purpose of display (see A3.1.1.1).7.3.6 If the apparatus standardization has not been checkedwithin the previous three months, perform at lest four newstandardization checks and use
45、 the mean as the value for No.7.3.7 The value of Ns will be used to determine the countratios for the current days use of the equipment. If, for anyreason, either the measured density or moisture content be-come suspect during the days use, perform another standard-ization to ensure that the equipme
46、nt is stable.8. Procedure8.1 Installation of Access Tubing (Casing):8.1.1 Drill the access hole or excavate a trench at the desiredlocation and install the access tube in a manner to maximizecontact with test material and minimize voids. The access tubesshould fit snugly into the access hole or tren
47、ch. Unstableconditions in fill material around the access tube may result inredistribution of solids over time, piping, or other phenomenathat will degrade precision. Voids caused during drilling, tubeinstallation, or backfilling, or a combination thereof, may causeerroneously low results. Excessive
48、 compaction of clay-richbackfill material will limit the effectiveness of moisture moni-toring for leak detection. Backfill should approximate thecomposition, water content, and bulk density of test material asnearly as possible.8.1.2 Grouting of annular spaces, if required, should be ofminimum func
49、tional thickness, and grout mixtures should notcontain excessive water. Grouts thicker than 2 in. 5 cm createhigh background counts that will obscure moisture contentchanges in fine-textured soils and severely limit meaningfuldensity measurements in all soil types. Grouting should not beused unless it is required to seal off flow pathways along theaccess tube, such as in some vertical borings and wheretrenches cross engineered barriers. Grouting can be accom-plished using procedures described in Test Methods D4428/D4428M.8.1.3 Record and note the pos
