1、Designation: D7830/D7830M 13Standard Test Method forIn-Place Density (Unit Weight) and Water Content of SoilUsing an Electromagnetic Soil Density Gauge1This standard is issued under the fixed designation D7830/D7830M; the number immediately following the designation indicates theyear of original ado
2、ption 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.1. Scope1.1 This test method covers the procedures for determiningin-place properti
3、es of non-frozen, unbound soil and soil aggre-gate mixtures such as total density, gravimetric water contentand relative compaction by measuring the electromagneticimpedance of the compacted soil.1.1.1 The method and device described in this test methodare intended for in-process quality control of
4、earthwork proj-ects. Site or material characterization is not an intended result.1.2 UnitsThe values stated in either SI units or inch-pound units given in brackets are to be regarded separately asstandard. The values stated in each system may not be exactequivalents; therefore, each system shall be
5、 used independentlyof the other. Combining values from the two systems mayresult in non-conformance with the standard.1.2.1 The gravitational 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 ma
6、ssis slugs. The rationalized slug unit is not given in this standard.1.2.2 In the engineering profession, it is customary practiceto use, interchangeably, units representing both mass and force,unless dynamic calculations are involved. This implicitlycombines two separate systems of units, that is,
7、the absolutesystem and the gravimetric system. It is undesirable to combinethe use of two separate systems within a single standard. Theuse of balances or scales recording pounds of mass (lbm), orthe recording of density in lbm/ft3should not be regarded asnonconformance with this standard.1.3 All ob
8、served and calculated values shall conform to theGuide for Significant Digits and Rounding established inPractice D6026.1.3.1 The procedures used to specify how data is collected,recorded, and calculated in this standard are regarded asindustry standard. In addition, they are representative of thesi
9、gnificant digits that should generally be retained. The proce-dures used do not consider material variation, purpose forobtaining the data, special purpose studies, or any consider-ations for the users objectives; and it is common practice toincrease or decrease the number of significant digits of r
10、eporteddata commensurate with these considerations. It is beyond thescope of this standard to consider significant digits used in theanalysis methods for engineering design.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibili
11、ty 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.NOTE 1ASTM International takes no position respecting the validityof any patent rights asserted in connection with any item mentioned in thiss
12、tandard. Users of this standard are expressly advised that determinationof the validity of any such patent rights, and the risk of infringement ofsuch rights, are entirely their own responsibility.2. Referenced Documents2.1 ASTM Standards:2D422 Test Method for Particle-Size Analysis of SoilsD653 Ter
13、minology Relating to Soil, Rock, and ContainedFluidsD698 Test Methods for Laboratory Compaction Character-istics of Soil Using Standard Effort (12 400 ft-lbf/ft3(600kN-m/m3)D1556 Test Method for Density and Unit Weight of Soil inPlace by Sand-Cone MethodD1557 Test Methods for Laboratory Compaction C
14、haracter-istics of Soil Using Modified Effort (56,000 ft-lbf/ft3(2,700 kN-m/m3)D2167 Test Method for Density and Unit Weight of Soil inPlace by the Rubber Balloon MethodD2216 Test Methods for Laboratory Determination of Water(Moisture) Content of Soil and Rock by MassD2937 Test Method for Density of
15、 Soil in Place by theDrive-Cylinder MethodD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock as1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.08 on Special an
16、dConstruction Control Tests.Current edition approved Feb. 1, 2013. Published April 2013. DOI: 10.1520/D7830-13.2For 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 s
17、tandards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1Used in Engineering Design and ConstructionD4253 Test Methods for Maximum Index Density and UnitWeight of Soils Using a Vibratory TableD
18、4254 Test Methods for Minimum Index Density and UnitWeight of Soils and Calculation of Relative DensityD4318 Test Methods for Liquid Limit, Plastic Limit, andPlasticity Index of SoilsD4643 Test Method for Determination of Water (Moisture)Content of Soil by Microwave Oven HeatingD4718 Practice for Co
19、rrection of Unit Weight and WaterContent for Soils Containing Oversize ParticlesD7382 Test Methods for Determination of Maximum DryUnit Weight and Water Content Range for EffectiveCompaction of Granular Soils Using a Vibrating HammerD4944 Test Method for Field Determination of Water (Mois-ture) Cont
20、ent of Soil by the Calcium Carbide Gas PressureTesterD4959 Test Method for Determination of Water (Moisture)Content of Soil By Direct HeatingD6026 Practice for Using Significant Digits in GeotechnicalDataD6938 Test Method for In-Place Density and Water Contentof Soil and Soil-Aggregate by Nuclear Me
21、thods (ShallowDepth)E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 Other Referenced Documents:“Development of a Non-Nuclear Soil Density Gauge toEliminate the Need for Nuclear Density Gauges”33. Terminology3.1 DefinitionsSee Terminology D653 for g
22、eneral defini-tions.3.2 Definitions of Terms Specific to This Standard:3.2.1 impedance, na measure of opposition to alternatingcurrent (AC).3.2.2 impedance spectroscopy, na method that measuresthe electromagnetic properties of a medium as a function offrequency.4. Summary of Test Method4.1 The total
23、 or wet density and water content of soil andsoil-aggregate are correlated to empirical data using an elec-tromagnetic impedance spectroscopy device. Electromagneticproperties of the soil are determined at specific frequencies bymeasuring the changes in the electromagnetic field. A functionis genera
24、ted that describes the relationship between electricalproperties over a range of frequencies. That function iscompared to an empirical model and other calibration checks todetermine water content and density.4.2 This method employs electromagnetic impedance spec-troscopy to determine the volumetric
25、water content and wetdensity. The measurement spectrum is made up of frequenciesranging from 30 kHz to 50 MHz.5. Significance and Use5.1 The method described determines wet density and watercontent by correlating complex impedance measurement datato an empirically developed model. The empirical mode
26、l isgenerated by comparing the electrical properties of typical soilsencountered in civil construction projects to their wet densitiesand water contents determined by other accepted methods.5.2 The test method described is useful as a rapid, non-destructive technique for determining the in-place tot
27、al densityand water content of soil and soil-aggregate mixtures and thedetermination of dry density.5.3 This method may be used for quality control andacceptance of compacted soil and soil-aggregate mixtures asused in construction and also for research and development.The non-destructive nature allo
28、ws for repetitive measurementsat a single test location and statistical analysis of the results.NOTE 2The quality of the result produced by this standard test methodis dependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that m
29、eet therequirements of Practice D3740 are generally considered capable ofcompetent and objective sampling/testing/inspection, and the like. Usersof this standard are cautioned that compliance with Practice D3740 doesnot in itself assure reliable results. Reliable results depend on manyfactors; Pract
30、ice D3740 provides a means of evaluation some of thosefactors.6. Interferences6.1 Anomalies in the test material with electrical impedanceproperties significantly different from construction soils andaggregate evaluated during soil model development, such asmetal objects or organic material, may aff
31、ect the accuracy ofthe test method.6.2 Chemical and mineralogical composition may affect theresults of a test. Examples of materials that may impact theresults include but are not limited to, quarried materialscontaining higher concentrations of iron, volcanic rock, andmaterials that have significan
32、t fractions of cemented particles,organic soils, recycled materials or materials containingasphalt, portland cement, lime, fly ash, or other stabilizingmodifiers. In most cases the effect may be satisfactorilyaddressed by following the Calibration Procedure in Section 7.6.3 A significant increase in
33、 the conductivity of the porewater such as from ground water that may contain significantsalt deposits or contaminants. In most cases the effect may besatisfactorily addressed by following the Calibration Procedurein Section 7.6.4 This test method applies only to non-frozen soil. Theelectrical prope
34、rties of soil change with temperature.Generally, testing should be limited to soil temperatures above10C 50F and below 40C 104F. Effects of temperatureon electrical properties of soils also depend on soil type.Clayey soils are more temperature sensitive than sandy soils.Accuracy of measurements impr
35、oves when the temperature ofsoil is close to the temperature used in the model calibration.Calibration for temperature effects should be done when soil3Prepared for The Department of Homeland Security under contract No.HSHQDC-07-C-00080. Dated October 31, 2008. Available from the U.S. Depart-ment of
36、 Homeland Security, Washington, D.C. 20528, http:/www.dhs.gov.D7830/D7830M 132temperatures differ by more than 10C 18F from modelcalibration temperatures. Calibration Procedures are given inSection 7.6.5 The accuracy of the results obtained by this test methodmay be influenced by poor or incorrect p
37、lacement of the deviceon the soil being tested. Non-homogeneous soils, non-uniformsurface texture, large air voids that may be present maydecrease the precision of the results. Correct placement of thesoil gauge is important to the quality of the electrical measure-ments collected by the device.6.6
38、Oversized particles in the measurement volume maycause an error in water content and/or density results. Wherelack of uniformity in the soil is suspected due to layering,aggregates, or voids, the test site should be excavated andvisually examined to determine if the material is representativeof the
39、in-situ material in general and if an oversize correctionis required in accordance with Practice D4718.6.7 Variation from actual values may increase for soilmaterial that is significantly drier or wetter than optimum watercontent as determined using Test Methods D698 or D1557.Variation from actual v
40、alues may increase for soil material thatis compacted to less than 80 % of the maximum dry density asdetermined using Test Methods D698 or D1557.6.8 Attempts to measure unknown in-place soils with a soilmodel that was generated from a limited range of wet densityor water content values, or both, may
41、 result in density andwater content errors.6.9 Strong electromagnetic fields such as those generated byhigh tension power lines may interfere with the device opera-tion.6.10 For a circular sensor 280 mm 11 in. in diameter, thetypical maximum measured volume is approximately 0.0034m30.12 ft3. The act
42、ual measured volume is indeterminate andvaries with the plate diameter, sensor configuration, andmaterial being tested. Results are typically influenced more bythe density and water content of the material near the surface.7. Apparatus4,57.1 Electromagnetic Soil Density GaugeA device capableof gener
43、ating an electromagnetic field and measuring thedifferential voltage change between two electrodes. An ex-ample of the device is shown in Fig. 1 and a sensor schematicsection and approximate electrical fields that sense the soil isshown in Fig. 2. While the exact details of construction of theappara
44、tus may vary, the system shall consist of:7.1.1 Electronic circuitry to provide power and signal con-ditioning to the sensor and to provide the data acquisition anddisplay functions. The circuitry shall be designed to perform acalibration of the unit over a range of conditions and materialsexpected
45、in the field.7.1.2 Internal circuitry suitable for displaying individualmeasurements to allow operators to record the results.7.1.3 A rugged housing designed for taking in-situ densityand water content measurements of soil and soil-aggregatemixtures during routine earthwork operations.7.1.4 Infrared
46、 Temperature Measuring Device, shall becapable of measuring the surface temperature of the materialbeing tested to 6 0.5C 6 1F throughout a range of 0 to50C 30 to 120F.7.2 Soil Calibration ContainerContainers for calibrationof the gauge as described in section 8.5.1, Container Calibra-tion.8. Calibr
47、ation8.1 For Factory Calibration information and requirementsplease refer to Annex A1.8.2 The soil density gauge has been designed to determinethe moisture and density in a compacted soil sample withoutthe need for special field generated soil models. The ability tomeasure moisture and density is ba
48、sed on multiple soil modelsthat were developed by studying various soil types. As the soildensity gauges measurement performance is based on thesemodels, there will be occasions where the soil being measuredis so different from one that has been studied previously that anadjustment may be required t
49、o enable the soil density gauge toproduce acceptable results.68.3 Determine the test parameters that will be used tocalibrate the device. For example, selection of a pre-existingsoil model or manual entry of soil model parameters forcalibration.8.3.1 Obtain a representative sample of soil from the sitewhere in-place testing is conducted or from the borrow source.8.3.2 Determine the laboratory compaction characteristicsof the material to be tested. Test Methods D698 or D1557 forfine grained soils and soil rock mixtures that exhibit a clearmaximu
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