1、Designation: D4718/D4718M 15Standard Practice forCorrection of Unit Weight and Water Content for SoilsContaining Oversize Particles1This standard is issued under the fixed designation D4718/D4718M; the number immediately following the designation indicates theyear of original adoption or, in the cas
2、e 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.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This
3、 practice presents a procedure for calculating theunit weights and water contents of soils containing oversizeparticles when the data are known for the soil fraction with theoversize particles removed.1.2 This practice also can be used to calculate the unitweights and water contents of soil fraction
4、s when the data areknown for the total soil sample containing oversize particles.1.3 This practice is based on tests performed on soils andsoil-rock mixtures in which the portion considered oversize isthat fraction of the material retained on the 4.75-mm No. 4sieve. Based on these tests, this practi
5、ce is applicable to soilsand soil-rock mixtures in which up to 40 % of the material isretained on the 4.75-mm No. 4 sieve. The practice also isconsidered valid when the oversize fraction is that portionretained on some other sieve, but the limiting percentage ofoversize particles for which the corre
6、ction is valid may belower. However, the practice is considered valid for materialshaving up to 30 % oversize particles when the oversize fractionis that portion retained on the 19-mm 34-in. sieve.1.4 The factor controlling the maximum permissible per-centage of oversize particles is whether interfe
7、rence betweenthe oversize particles affects the unit weight of the finerfraction. For some gradations, this interference may begin tooccur at lower percentages of oversize particles, so the limitingpercentage must be lower for these materials to avoid inaccu-racies in the computed correction. The pe
8、rson or agency usingthis practice shall determine whether a lower percentage is tobe used.1.5 This practice may be applied to soils with any percent-age of oversize particles subject to the limitations given in 1.3and 1.4. However, the correction may not be of practicalsignificance for soils with on
9、ly small percentages of oversizeparticles. The person or agency specifying this practice shallspecify a minimum percentage of oversize particles belowwhich the practice need not be applied. If a minimum percent-age is not specified, 5 % shall be used.1.6 This practice may not be applicable to soil-r
10、ock mix-tures which degrade under field compaction.1.7 UnitsThe values stated in either SI Units or inch-pound units are to be regarded separately as standard. Thevalues stated in each system may not be exact equivalents;therefore, each system shall be used independently of the other.Combining value
11、s from the two systems may result in non-conformance with the standard.1.7.1 It is common practice in the engineering profession toconcurrently use pounds to represent both a unit of mass (lbm)and a force (lbf). This implicitly combines two separatesystems of units; that is, the absolute system and
12、the gravita-tional system. It is scientifically undesirable to combine the useof two separate sets of inch-pound units within a singlestandard. This standard has been written using the gravitationalsystem of units when dealing with the inch-pound system. Inthis system, the pound (lbf) represents a u
13、nit of force (weight).However, the use of balances or scales recording pounds ofmass (lbm) or the recording of density in lbm/ft3shall not beregarded as a non conformance with this standard.NOTE 1Sieve size is identified by its standard designation in Speci-fication E11. The alternative designation
14、given in brackets is for informa-tion only and does not represent a different standard sieve size.1.8 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.8.1 The procedures used to specify how data are collected/recorde
15、d and calculated in this standard are regarded as theindustry standard. In addition, they are representative of thesignificant digits that generally should be retained. The proce-dures used do not consider material variation, purpose forobtaining data, special purpose studies, or any considerationsf
16、or the users objectives; and it is common practice to increaseor reduce significant digits of reported data to commensuratewith these considerations. It is beyond the scope of these test1This practice is under the jurisdiction of ASTM Committee D18 on Soil andRockand is the direct responsibility of
17、Subcommittee D18.03 on Texture, Plasticityand Density Characteristics of Soils.Current edition approved Dec. 15, 2015. Published January 2016. Originallyapproved in 1987. Last previous edition approved in 2007 as D4718 87 (2007).DOI: 10.1520/D4718_D4718M-15.*A Summary of Changes section appears at t
18、he end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1methods to consider significant digits used in analysis methodsfor engineering design.1.9 This practice offers a set of instructions for performingone or more spec
19、ific operations. This document cannot replaceeducation or experience and should be used in conjunctionwith professional judgment. Not all aspects of this practice maybe applicable in all circumstances. This ASTM standard is notintended to represent or replace the standard of care by whichthe adequac
20、y of a given professional service must be judged,nor should this document be applied without consideration ofa projects many unique aspects. The word “Standard” in thetitle of this document means only that the document has beenapproved through the ASTM consensus process.NOTE 2The quality of the resu
21、lt produced by this standard isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/sampling/inspection/etc. Users of th
22、is standard arecautioned that compliance with Practice D3740 does not in itself ensurereliable results. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those factors.2. Referenced Documents2.1 ASTM Standards:2C127 Test Method for Relative Density (Specif
23、ic Gravity)and Absorption of Coarse AggregateD653 Terminology 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
24、 MethodD1557 Test Methods for Laboratory Compaction Character-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
25、Soil and Rock by MassD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4253 Test Methods for Maximum Index Density and UnitWeight of Soils Using a Vibratory TableD6026 Practice for Using Significant
26、 Digits in GeotechnicalDataD6938 Test Methods for In-Place Density and Water Contentof Soil and Soil-Aggregate by Nuclear Methods (ShallowDepth)D7382 Test Methods for Determination of Maximum DryUnit Weight and Water Content Range for EffectiveCompaction of Granular Soils Using a Vibrating HammerD76
27、98 Test Method for In-Place Estimation of Density andWater Content of Soil and Aggregate by Correlation withComplex Impedance MethodD7830 Test Method for In-Place Density (Unit Weight) andWater Content of Soil Using an Electromagnetic SoilDensity GaugeE11 Specification for Woven Wire Test Sieve Clot
28、h and TestSieves3. Terminology3.1 For definitions of common technical terms used in thisstandard, refer to Terminology D653.3.2 Definitions:3.2.1 oversize particles, nparticles that are larger thanthose allowed and normally removed for the normal perfor-mance of a standard test method.4. Significanc
29、e and Use4.1 Compaction tests on soils performed in accordance withTest Methods D698, D1557, D4253, and D7382 place limita-tions on the maximum size of particles that may be used in thetest. If a soil contains cobbles or gravel, or both, test optionsmay be selected which result in particles retained
30、 on a specificsieve being discarded (for example the 4.75-mm No. 4, the19-mm 34-in. or other appropriate size) and the test per-formed on the finer fraction. The unit weight-water contentrelations determined by the tests reflect the characteristics ofthe actual material tested, and not the character
31、istics of the totalsoil material from which the test specimen was obtained.4.2 It is common engineering practice to use laboratorycompaction tests for the design, specification, and constructioncontrol of soils used in earth construction. If a soil used inconstruction contains large particles, and o
32、nly the finer fractionis used for laboratory tests, some method of correcting thelaboratory test results to reflect the characteristics of the totalsoil is needed. This practice provides a mathematical equationfor correcting the unit weight and water content of the finerfraction of a soil, tested to
33、 determine the unit weight and watercontent of the total soil.4.3 Similarly, as utilized in Test Methods D1556, D2167,D6938, D7698, and D7830, this practice provides a means forcorrecting the unit weight and water content of field compactedsamples of the total soil, so that values can be compared wi
34、ththose for a laboratory compacted finer fraction.NOTE 3When this practice is used for construction control, the usingagency should specify whether the maximum unit weight value used forreference is the unit weight including oversize fraction or the unit weightof the finer fraction. Calculated value
35、s of percent compaction based onthis correction practice will vary depending on which unit weight value isused for reference.5. Procedure5.1 Correction of Unit Weight and Water Content for TotalSample:5.1.1 Prepare the sample from which compaction test speci-mens are to be taken in accordance with p
36、rovisions of thespecific test methods. Determine the mass of the moist finerfraction of the sample and the mass of the moist oversize (plus4.75-mm No. 4 or plus 19-mm 34-in., or other appropriatesize) fraction of the total sample. Determine the water content2For referenced ASTM standards, visit the
37、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.D4718/D4718M 152of each of the two fractions based upon dry mass, in accor-dance with Test Methods D221
38、6. With some test methods, thecorrection for water content may not apply. Calculate the massof the dry finer fraction and the dry oversize fraction asfollows:MD5 MM/11w 100! (1)where:MD= mass of the dry material (finer or oversize fraction), g,MM= mass of the moist material (finer or oversize fracti
39、on),g, andw = water content of the respective finer or oversizefractions expressed in percent.5.1.2 Calculate the percentage of the finer fraction and ofthe oversize fraction of the sample by dry mass as follows:PF5 100 MDF/MDF1MDC! (2)andPC5 100 MDC/MDF1MDC! (3)where:PF= percent of finer fraction b
40、y mass,PC= percent of oversize fraction by mass,MDF= mass of dry finer fraction, andMDC= mass of dry oversize fraction.5.1.3 Determine the relative density (specific gravity) (ovendried) (GM) of the oversize fraction in accordance with TestMethod C127.5.1.4 Calculate the corrected water content and
41、correcteddry unit weight of the total material (combined finer andoversize fractions), as follows:wT5 wFPF1wCPC! (4)where:wT= corrected water content of combined finer and oversizefractions expressed in percent,wF= water content of finer fraction expressed as a decimal,wC= water content of oversize
42、fraction expressed as adecimal,andDT5 100 DFGM/DFPC1GMPF! (5)where:DT= corrected dry unit weight of the total material (com-bined finer and oversize fractions),GM= relative density (specific gravity) (oven dried) asdetermined by Test Method C127,DF= dry unit weight of the finer fraction, and= unit w
43、eight of water (62.42 lbf/ft3or 9.802 kN/m3)(see Note 4).NOTE 4The unit weight of water may vary slightly depending on thegeographical location and water temperature.5.2 Correction of Unit Weight and Water Content for FinerFraction of a Soil Sample:5.2.1 When it is desired to compare the unit weight
44、 andwater content of a field-compacted soil containing oversizeparticles with the results of laboratory compaction tests on thefiner fraction, the following procedure may be used:5.2.1.1 A sample of the total material is obtained in the fieldat the desired test location in conjunction with a unit dr
45、y weight(DT) and water content (w) determination by acceptable fieldmethods of density and unit weight determination. Since thispractice is usually used for materials containing coarse graveland cobble size particles, special care should be taken to ensurethat the volume of material sampled is adequ
46、ate to accuratelyrepresent the material in the field at the test location.5.2.1.2 Remove the oversize particles of plus 4.75-mm No.4, 19-mm 34-in., or any other appropriate size from the fieldsample and determine the percentage of oversize particles inthe total sample. If, in the laboratory testing
47、of the materials,the relative density (specific gravity) (oven dried) by TestMethod C127, and the water content by Test Methods D2216of the oversize particles have been determined, these valuesmay be used in the calculations. Otherwise, it will be necessaryto determine the relative density (specific
48、 gravity) (oven dried)by Test Method C127.5.2.1.3 Calculate the water content of the finer fraction ofthe field sample as follows:wF5 100 wT2 wCPC!/PF(6)where:wF= water content of finer fraction expressed in percent,wT= corrected water content of combined finer and oversizefractions expressed in per
49、cent, andwC= water content of oversize fraction expressed in percent.5.2.1.4 Calculate the dry unit weight of the finer fraction ofthe field sample as follows:DF5 DTGMPF100 GMw2 DTPC! (7)6. Report: Test Data Sheet(s)/Form(s)6.1 The methodology used to specify how data are recordedon the test data sheet(s)/form(s), as given below, is covered in1.8.6.2 Record as a minimum the following general information(data):6.2.1 Project information, such as project number, projectname, project location.6.2.2 The identification or sourc
