1、Designation: D2488 171Standard Practice forDescription and Identification of Soils (Visual-ManualProcedures)1This standard is issued under the fixed designation D2488; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t revision. A number in parentheses indicates the year of last reapproval. Asuperscript 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.1NOTEEditorially corrected Fig. 2 in March 2018
3、.1. Scope*1.1 This practice covers procedures for the description ofsoils for engineering purposes.1.2 This practice also describes a procedure for identifyingsoils, at the option of the user, based on the classificationsystem described in Test Method D2487. The identification isbased on visual exam
4、ination and manual tests. It shall beclearly stated in reporting, the soil identification is based onvisual-manual procedures.1.2.1 When precise classification of soils for engineeringpurposes is required, the procedures outlined in Test MethodD2487 shall be used.1.2.2 In this practice, the identifi
5、cation procedures assigninga group symbol and name are limited to soil particles smallerthan 3 in. (75 mm).1.2.3 The identification portion of this practice is limited tonaturally occurring soils. Specimens used for identificationmay be either intact or disturbed.NOTE 1This practice may be used as a
6、 descriptive system applied tosuch materials as shale, claystone, shells, crushed rock, etc. (see AppendixX2).1.3 The descriptive information in this practice may be usedwith other soil classification systems or for materials other thannaturally occurring soils.1.4 UnitsThe values stated in inch-pou
7、nd units are to beregarded as standard. The values given in parentheses arerationalized conversions to SI units that are provided forinformation only and are not considered standard. The sievedesignations are identified using the “alternative” system inaccordance with Practice E11.1.5 This standard
8、does not purport 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, health, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.For specific prec
9、autionary statements see Section 8.1.6 This practice offers a set of instructions for performingone or more specific 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 c
10、ircumstances. This ASTM standard is notintended to represent or replace the standard of care by whichthe adequacy 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 documen
11、t means only that the document has beenapproved through the ASTM consensus process.1.7 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guid
12、es and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and ContainedFluidsD1452 Practice for Soil Exploration and Sampling by AugerBoringsD1586 Test Method for Stand
13、ard Penetration Test (SPT) andSplit-Barrel Sampling of SoilsD1587 Practice for Thin-Walled Tube Sampling of Fine-Grained Soils for Geotechnical PurposesD2113 Practice for Rock Core Drilling and Sampling ofRock for Site Exploration1This practice is under the jurisdiction of ASTM Committee D18 on Soil
14、 andRock and is the direct responsibility of Subcommittee D18.07 on Identification andClassification of Soils.Current edition approved July 15, 2017. Published August 2017. Originallyapproved in 1966. Last previous edition approved in 2009 as D2488 09a. DOI:10.1520/D2488-17E01.2For referenced ASTM s
15、tandards, 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM Int
16、ernational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards
17、, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1D2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspec
18、tion of Soil and Rock asUsed in Engineering Design and ConstructionD4083 Practice for Description of Frozen Soils (Visual-Manual Procedure)D4427 Classification of Peat Samples by Laboratory TestingE11 Specification for Woven Wire Test Sieve Cloth and TestSieves3. Terminology3.1 Definitions:3.1.1 For
19、 definitions of common technical terms in thisstandard, refer to Terminology D653.3.1.2 cobblesparticles of rock that will pass a 12-in.(300-mm) square opening and be retained on a 3-in. (75-mm)sieve.3.1.3 bouldersparticles of rock that will not pass a 12-in.(300-mm) square opening.3.1.4 claysoil pa
20、ssing a No. 200 (75-m) sieve that can bemade to exhibit plasticity (putty-like properties) within a rangeof water contents, and that exhibits considerable strength whenair-dried. For classification, a clay is a fine-grained soil, or thefine-grained portion of a soil, with a plasticity index equal to
21、 orgreater than 4, and the plot of plasticity index versus liquidlimit falls on or above the “A” line (see Fig. 4 of Test MethodD2487).3.1.5 gravelparticles of rock that will pass a 3-in. (75-mm) sieve and be retained on a No. 4 (4.75-mm) sieve with thefollowing subdivisions:3.1.5.1 coarsepasses a 3
22、-in. (75-mm) sieve and is retainedon a34-in. (19-mm) sieve.3.1.5.2 finepasses a34-in. (19-mm) sieve and is retainedon a No. 4 (4.75-mm) sieve.3.1.6 organic claya clay with sufficient organic content toinfluence the soil properties. For classification, an organic clayis a soil that would be classifie
23、d as a clay, except that its liquidlimit value after oven drying is less than 75 % of its liquid limitvalue before oven drying.3.1.7 organic silta silt with sufficient organic content toinfluence the soil properties. For classification, an organic siltis a soil that would be classified as a silt exc
24、ept that its liquidlimit value after oven drying is less than 75 % of its liquid limitvalue before oven drying.3.1.8 peata soil composed primarily of vegetable tissue invarious stages of decomposition usually with an organic odor,a dark brown to black color, a spongy consistency, and atexture rangin
25、g from fibrous to amorphous.3.1.9 sandparticles of rock that will pass a No. 4 (4.75-mm) sieve and be retained on a No. 200 (75-m) sieve with thefollowing subdivisions:3.1.9.1 coarsepasses a No. 4 (4.75-mm) sieve and isretained on a No. 10 (2.00-mm) sieve.3.1.9.2 mediumpasses a No. 10 (2.00-mm) siev
26、e and isretained on a No. 40 (425-m) sieve.3.1.9.3 finepasses a No. 40 (425-m) sieve and is retainedon a No. 200 (75-m) sieve.3.1.10 siltsoil passing a No. 200 (75-m) sieve that isnonplastic or very slightly plastic and that exhibits little or nostrength when air dry. For classification, a silt is a
27、 fine-grainedsoil, or the fine-grained portion of a soil, with a plasticity indexless than 4, or the plot of plasticity index versus liquid limitfalls below the “A” line (see Fig. 4 of Test Method D2487).3.1.11 fine-grained soilssoils that are made up of 50 % ormore particles that will pass a No. 20
28、0 (75 m) sieve.3.1.12 coarse-grained soilssoils that are made up of morethan 50 % particles that will be retained on a No. 200 (75 m)sieve.4. Summary of Practice4.1 Using visual examination and simple manual tests, thispractice gives standardized criteria and procedures for describ-ing and identifyi
29、ng soils.4.2 The soil can be given an identification by assigning agroup symbol(s) and name. The flow charts, Fig. 1a and Fig. 1bfor fine-grained soils, and Fig. 2, for coarse-grained soils, canbe used to assign the appropriate group symbol(s) and name. Ifthe soil has properties which do not distinc
30、tly place it into aspecific group, borderline symbols may be used, see AppendixX3.5. Significance and Use5.1 The descriptive information required in this practice canbe used to describe a soil to aid in the evaluation of itssignificant properties for engineering use.5.2 The descriptive information r
31、equired in this practiceshould be used to supplement the classification of a soil asdetermined by Test Method D2487.5.3 This practice may be used in identifying soils using theclassification group symbols and names as prescribed in TestMethod D2487. Since the names and symbols used in thispractice t
32、o identify the soils are the same as those used in TestMethod D2487, it shall be clearly stated in reports and all otherappropriate documents, that the classification symbol and nameare based on visual-manual procedures.5.4 This practice is to be used for identification of soils inthe field, laborat
33、ory, or any other location where soil samplesare inspected and described.5.5 This practice may be used to group similar soil samplesto reduce the number of laboratory tests necessary for positivesoil classification.NOTE 2The ability to describe and identify soils correctly is learnedmore readily und
34、er the guidance of experienced personnel, but it may alsobe acquired systematically by comparing numerical laboratory test resultsfor typical soils of each type with their visual and manual characteristics.5.6 Soil samples from a given boring, test pit or locationwhich appear to have similar charact
35、eristics are not required tofollow all of the procedures in this practice, providing at leastone sample is completely described and identified. Thesesamples may follow only the necessary procedures to deter-mine they are “similar” and shall be labeled as such.D2488 17125.7 This practice may be used
36、in combination with PracticeD4083 when working with frozen soils.NOTE 3The quality of the result 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 genera
37、lly considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those fac
38、tors.6. Apparatus6.1 Small Knife or Spatula6.2 Test Tube and Stopper (optional)6.3 Jar with Lid (optional)6.4 Hand Lens (optional)6.5 Shallow Pan (optional)7. Reagents7.1 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean water from a city watersupply or natura
39、l source, including non-potable water.7.2 Hydrochloric AcidA small bottle of dilute hydrochlo-ric acid (HCl) one part HCl (10 N) to three parts distilled water(This reagent is optional for use with this practice). See Section8.NOTEPercentages are based on estimating amounts of fines, sand, and grave
40、l to the closest 5 %.FIG. 1a Flow Chart for Identifying Inorganic Fine-Grained Soil (50 % or more fines)NOTEPercentages are based on estimating amounts of fines, sand, and gravel to the closest 5 %.FIG. 1 b Flow Chart for Identifying Organic Fine-Grained Soil (50 % or more fines)D2488 17138. Safety
41、Precautions8.1 When preparing the dilute HCl solution of one partconcentrated hydrochloric acid (10 N) to three parts of distilledwater, slowly add acid into water following necessary safetyprecautions. Handle with caution, utilize personal protectiveequipment and store safely. If solution comes int
42、o contact withthe skin or eyes, rinse thoroughly with water.8.2 CautionAcid shall be added to the water. Do not addwater to the acid as this may cause an adverse reaction.9. Sampling9.1 The sample shall be considered to be representative ofthe stratum from which it was obtained by an appropriate,acc
43、epted, or standard procedure.NOTE 4Preferably, the sampling procedure should be identified ashaving been conducted in accordance with Practices D1452, D1587,orD2113, or Test Method D1586.9.2 The sample shall be carefully identified as to origin.NOTE 5Remarks as to the origin may take the form of a b
44、oringnumber and sample number in conjunction with a project number, ageologic stratum, a pedologic horizon or a location description withrespect to a permanent monument, a grid system or a station number andoffset with respect to a stated centerline and a depth or elevation.9.3 For accurate descript
45、ion and identification, the mini-mum amount of the specimen to be examined shall be inaccordance with Table 1.NOTE 6If random isolated particles are encountered that are signifi-cantly larger than the particles in the soil matrix, the soil matrix can beaccurately described and identified in accordan
46、ce with the preceding table.9.4 If the sample or specimen being examined is smallerthan the minimum recommended specimen size, the reportshall include a remark stating as such.NOTEPercentages are based on estimating amounts of fines, sand, and gravel to the closest 5 %.NOTEIt is suggested that a dis
47、tinction be made between dual symbols and borderline symbols.Dual SymbolA dual symbol is two symbols separated by a hyphen, for example, GP-GM, SW-SC, CL-ML used to indicate that the soil has been identified as havingthe properties of a classification in accordance with Test Method D2487 where two s
48、ymbols are required. Two symbols are required when the soil has between 5 and 12 %fines or when the liquid limit and plasticity index values plot in the CL-ML area of the plasticity chart.Borderline SymbolA borderline symbol is two symbols separated by a slash, for example, CL/CH, GM/SM, CL/ML. A bo
49、rderline symbol should be used to indicate thatthe soil has been identified as having properties that do not distinctly place the soil into a specific group (see Appendix X3).FIG. 2 Flow Chart for Identifying Coarse-Grained Soils (less than 50 % fines)TABLE 1 Minimum Specimen Dry Mass RequirementsMaximum ParticleSize, Sieve OpeningMinimum SpecimenSize, by Dry MassNo. 4 (4.75 mm) 0.25 lb (110 g)38 in. (9.5 mm) 0.5 lb (220 g)34 in. (19.0 mm) 2.2 lb (1.0 kg)112 in. (38.1 mm) 18 lb (8.0 kg)3 in. (75.0 mm) 132 lb (60.0 kg)D2488 1714
