1、Designation: D 2488 06Standard Practice forDescription and Identification of Soils (Visual-ManualProcedure)1This standard is issued under the fixed designation D 2488; 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 (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This practice covers procedures for th
3、e 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 D 2487. The identification isbased on visual examination and manual tests. It must beclearly stated
4、in reporting an identification that it is based onvisual-manual procedures.1.2.1 When precise classification of soils for engineeringpurposes is required, the procedures prescribed in Test MethodD 2487 shall be used.1.2.2 In this practice, the identification portion assigning agroup symbol and name
5、is limited to soil particles smaller than3 in. (75 mm).1.2.3 The identification portion of this practice is limited tonaturally occurring soils (disturbed and undisturbed).NOTE 1This practice may be used as a descriptive system applied tosuch materials as shale, claystone, shells, crushed rock, etc.
6、 (seeAppendixX2).1.3 The descriptive information in this practice may be usedwith other soil classification systems or for materials other thannaturally occurring soils.1.4 The values stated in inch-pound units are to be regardedas the standard.1.5 This standard does not purport to address all of th
7、esafety problems, 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 specificprecautionary statements see Section 8.1.6 This practice
8、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 circumstances. This ASTM standard is notintended to re
9、present 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 document means only that the document has beenapproved throu
10、gh the ASTM consensus process.2. Referenced Documents2.1 ASTM Standards:2D 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 1452 Practice for Soil Investigation and Sampling byAuger BoringsD 1586 Test Method for Penetration Test and Split-BarrelSampling of SoilsD 1587 Practice for Thin-W
11、alled Tube Sampling of Soilsfor Geotechnical PurposesD2113 Practice for Rock Core Drilling and Sampling ofRock for Site InvestigationD 2487 Practice for Classification of Soils for EngineeringPurposes (Unified Soil Classification System)D 3740 Practice for Minimum Requirements for AgenciesEngaged in
12、 the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and ConstructionD 4083 Practice for Description of Frozen Soils (Visual-Manual Procedure)3. Terminology3.1 DefinitionsExcept as listed below, all definitions arein accordance with Terminology D 653.NOTE 2For particles retai
13、ned on a 3-in. (75-mm) US standard sieve,the following definitions are suggested:Cobblesparticles of rock that will pass a 12-in. (300-mm) squareopening and be retained on a 3-in. (75-mm) sieve, andBouldersparticles of rock that will not pass a 12-in. (300-mm) squareopening.1This practice is under t
14、he jurisdiction of ASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.07 on Identification andClassification of Soils.Current edition approved Nov. 1, 2006. Published November 2006. Originallyapproved in 1966. Last previous edition approved in 2000 as D 2488 00.2
15、For 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.1*A Summary of Changes section appears at the end of this stan
16、dard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.1 claysoil passing 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
17、whenair-dry. For classification, a clay is a fine-grained soil, or thefine-grained portion of a soil, with a plasticity index equal to orgreater than 4, and the plot of plasticity index versus liquidlimit falls on or above the “A” line (see Fig. 3 of Test MethodD 2487).3.1.2 gravelparticles of rock
18、that will pass a 3-in. (75-mm) sieve and be retained on a No. 4 (4.75-mm) sieve with thefollowing subdivisions:coarsepasses a 3-in. (75-mm) sieve and is retained on a34-in. (19-mm) sieve.finepasses a34-in. (19-mm) sieve and is retained on a No.4 (4.75-mm) sieve.3.1.3 organic claya clay with sufficie
19、nt organic content toinfluence the soil properties. For classification, an organic clayis a soil that would be classified as a clay, except that its liquidlimit value after oven drying is less than 75 % of its liquid limitvalue before oven drying.3.1.4 organic silta silt with sufficient organic cont
20、ent toinfluence the soil properties. For classification, an organic siltis a soil that would be classified as a silt except that its liquidlimit value after oven drying is less than 75 % of its liquid limitvalue before oven drying.3.1.5 peata soil composed primarily of vegetable tissue invarious sta
21、ges of decomposition usually with an organic odor,a dark brown to black color, a spongy consistency, and atexture ranging from fibrous to amorphous.3.1.6 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:coarsepasses
22、 a No. 4 (4.75-mm) sieve and is retained ona No. 10 (2.00-mm) sieve.mediumpasses a No. 10 (2.00-mm) sieve and is retainedon a No. 40 (425-m) sieve.finepasses a No. 40 (425-m) sieve and is retained on aNo. 200 (75-m) sieve.3.1.7 siltsoil passing a No. 200 (75-m) sieve that isnonplastic or very slight
23、ly plastic and that exhibits little or nostrength when air dry. For classification, a silt is a 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. 3 of Test Method D 2487).
24、4. Summary of Practice4.1 Using visual examination and simple manual tests, thispractice gives standardized criteria and procedures for describ-ing and identifying 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-g
25、rained 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 distinctly place it into aspecific group, borderline symbols may be used, see AppendixX3.NOTE 3It is suggested that a distinction be made between
26、dualsymbols 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 hasbeen identified as having the properties of a classification in accordancewith Test Method D 2487 where two symbols are required. Two sy
27、mbolsare required when the soil has between 5 and 12 % fines or when the liquidlimit and plasticity index values plot in the CL-ML area of the plasticitychart.Borderline SymbolA borderline symbol is two symbols separated by aslash, for example, CL/CH, GM/SM, CL/ML.Aborderline symbol shouldbe used to
28、 indicate that the soil has been identified as having propertiesthat do not distinctly place the soil into a specific group (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 prope
29、rties for engineering use.5.2 The descriptive information required in this practiceshould be used to supplement the classification of a soil asdetermined by Test Method D 2487.5.3 This practice may be used in identifying soils using theclassification group symbols and names as prescribed in TestMeth
30、od D 2487. Since the names and symbols used in thispractice to identify the soils are the same as those used in TestMethod D 2487, it shall be clearly stated in reports and allother appropriate documents, that the classification symbol andname are based on visual-manual procedures.5.4 This practice
31、is to be used not only for identification ofsoils in the field, but also in the office, laboratory, or whereversoil samples are inspected and described.5.5 This practice has particular value in grouping similarsoil samples so that only a minimum number of laboratory testsneed be run for positive soi
32、l classification.NOTE 4The ability to describe and identify soils correctly is learnedmore readily under 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 characte
33、ristics.5.6 When describing and identifying soil samples from agiven boring, test pit, or group of borings or pits, it is notnecessary to follow all of the procedures in this practice forevery sample. Soils which appear to be similar can be groupedtogether; one sample completely described and identi
34、fied withthe others referred to as similar based on performing only a fewof the descriptive and identification procedures described inthis practice.5.7 This practice may be used in combination with PracticeD 4083 when working with frozen soils.NOTE 5Notwithstanding the statements on precision and bi
35、as con-tained in this standard: The precision of this test method is dependent onthe competence of the personnel performing it and the suitability of theequipment and facilities used. Agencies that meet the criteria of PracticeD 3740 are generally considered capable of competent and objectivetesting
36、. Users of this test method are cautioned that compliance withPractice D 3740 does not in itself assure reliable testing. Reliable testingdepends on several factors; Practice D 3740 provides a means forevaluating some of those factors.6. Apparatus6.1 Required Apparatus:6.1.1 Pocket Knife or Small Sp
37、atula.6.2 Useful Auxiliary Apparatus:D24880626.2.1 Small Test Tube and Stopper (or jar with a lid).6.2.2 Small Hand Lens.7. Reagents7.1 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean water from a city watersupply or natural source, including non-potable wat
38、er.7.2 Hydrochloric AcidA small bottle of dilute hydrochlo-ric acid, HCl, one part HCl (10 N) to three parts water (Thisreagent is optional for use with this practice). See Section 8.8. Safety Precautions8.1 When preparing the dilute HCl solution of one partconcentrated hydrochloric acid (10 N) to t
39、hree parts of distilledwater, slowly add acid into water following necessary safetyprecautions. Handle with caution and store safely. If solutioncomes into contact with the skin, rinse thoroughly with water.8.2 CautionDo not add water to acid.9. Sampling9.1 The sample shall be considered to be repre
40、sentative ofthe stratum from which it was obtained by an appropriate,accepted, or standard procedure.NOTE 6Preferably, the sampling procedure should be identified ashaving been conducted in accordance with Practices D 1452, D 1587, orD2113, or Test Method D 1586.9.2 The sample shall be carefully ide
41、ntified as to origin.NOTE 7Remarks as to the origin may take the form of a boringnumber and sample number in conjunction with a job number, a geologicstratum, a pedologic horizon or a location description with respect to apermanent monument, a grid system or a station number and offset withrespect t
42、o a stated centerline and a depth or elevation.9.3 For accurate description and identification, the mini-mum amount of the specimen to be examined shall be inaccordance with the following schedule:NOTE 1Percentages are based on estimating amounts of fines, sand, and gravel to the nearest 5 %.FIG. 1a
43、 Flow Chart for Identifying Inorganic Fine-Grained Soil (50 % or more fines)NOTE 1Percentages are based on estimating amounts of fines, sand, and gravel to the nearest 5 %.FIG. 1 b Flow Chart for Identifying Organic Fine-Grained Soil (50 % or more fines)D2488063Maximum Particle Size,Sieve OpeningMin
44、imum Specimen Size,Dry Weight4.75 mm (No. 4) 100 g (0.25 lb)9.5mm(38 in.) 200 g (0.5 lb)19.0mm(34 in.) 1.0kg(2.2lb)38.1mm(112 in.) 8.0 kg (18 lb)75.0 mm (3 in.) 60.0 kg (132 lb)NOTE 8If random isolated particles are encountered that are signifi-cantly larger than the particles in the soil matrix, th
45、e soil matrix can beaccurately described and identified in accordance with the preceedingschedule.9.4 If the field sample or specimen being examined issmaller than the minimum recommended amount, the reportshall include an appropriate remark.10. Descriptive Information for Soils10.1 AngularityDescri
46、be the angularity of the sand(coarse sizes only), gravel, cobbles, and boulders, as angular,subangular, subrounded, or rounded in accordance with thecriteria in Table 1 and Fig. 3. A range of angularity may bestated, such as: subrounded to rounded.10.2 ShapeDescribe the shape of the gravel, cobbles,
47、 andboulders as flat, elongated, or flat and elongated if they meetthe criteria in Table 2 and Fig. 4. Otherwise, do not mention theshape. Indicate the fraction of the particles that have the shape,such as: one-third of the gravel particles are flat.10.3 ColorDescribe the color. Color is an importan
48、tproperty in identifying organic soils, and within a givenlocality it may also be useful in identifying materials of similargeologic origin. If the sample contains layers or patches ofvarying colors, this shall be noted and all representative colorsshall be described. The color shall be described fo
49、r moistsamples. If the color represents a dry condition, this shall bestated in the report.10.4 OdorDescribe the odor if organic or unusual. Soilscontaining a significant amount of organic material usuallyhave a distinctive odor of decaying vegetation. This is espe-cially apparent in fresh samples, but if the samples are dried,the odor may often be revived by heating a moistened sample.If the odor is unusual (petroleum product, chemical, and thelike), it shall be described.10.5 Moisture ConditionDescribe the moisture conditionas dry, moi
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