ASTM D2487-17 (2025) PDF

Full title and description

ASTM D2487-17 — Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System). This practice provides the Unified Soil Classification System (USCS) for assigning group symbols and group names to naturally occurring mineral and organo‑mineral soils based on laboratory particle‑size characteristics and Atterberg limits; the document has been maintained as D2487-17 and was reaffirmed/updated in 2025 as D2487-17R25 (published/reissued in early 2025).

Abstract

Defines the USCS procedure for classifying soils for engineering purposes using laboratory determinations of particle‑size distribution, liquid limit, and plasticity index. The practice describes group symbols and names, use of dual or borderline symbols, sample portion to be tested (portion passing the 3‑in. (75 mm) sieve), and notes intended uses and limitations for engineering investigations.

General information

• Status: Active — reaffirmed/issued as D2487-17R25 (D2487-17) in 2025.
• Publication date: Original edition: 14 December 2017; current/reaffirmation date (R25): early 2025 (Feb 12, 2025 noted as last update on ASTM record).
• Publisher: ASTM International.
• ICS / categories: 93.020 — Earth works, excavations, foundation construction, underground works (soil and geotechnical engineering).
• Edition / version: Designation: D2487-17; reaffirmed/maintenance identifier: D2487-17R25 (2025 reissue).
• Number of pages: 10 pages (concise practice).

Scope

This practice describes a classification system for mineral and organo‑mineral soils for engineering purposes, based on laboratory measurement of particle‑size characteristics (gradation) together with liquid limit and plasticity index (Atterberg limits). It is intended for qualitative classification when a standardised engineering grouping is required; it applies to naturally occurring soils and is typically applied to the fraction passing a 3‑in. (75 mm) sieve. Use with other ASTM practices/tests is recommended when quantitative performance properties are needed.

Key topics and requirements

• Unified Soil Classification System (USCS) group symbols and group names (e.g., GW, GP, GM, SW, CL, CH, ML, MH, OL, OH, PT, etc.).
• Laboratory basis: particle‑size distribution (gradation) and Atterberg limits (liquid limit and plasticity index) determine classification.
• Rules for dual symbols (when fines content 5–12% or plasticity chart cross‑hatched area) and borderline symbols (slash) where tests place soils near group boundaries.
• Specifies the portion of sample to classify (passing the 3‑in. / 75 mm sieve) and notes the system is qualitative — supplementary quantitative tests are advised for design.
• Notes on applicability with other practices: recommended reference to Practice D2488 for field description, Test Methods such as D422 (particle‑size analysis) and D4318 (Atterberg limits), and guidance on laboratory competence (Practice D3740).

Typical use and users

Used by geotechnical and civil engineers, laboratory technicians, construction and earthworks contractors, surveying and site investigation teams, materials testing labs, and educators. Typical applications include preliminary site investigation reports, field/laboratory soil logs, specification and acceptance of fill or subgrade materials, training in soil classification, and as a standard reference when reporting soil group symbols in project documentation.

Related standards

Commonly referenced and used alongside: Practice D2488 (Description and Identification of Soils), Test Method D422 (Particle‑Size Analysis of Soils), Test Methods D4318 (Liquid Limit, Plastic Limit, Plasticity Index), Practice D4083 (frozen soils), and Practice D3740 (laboratory competence/quality). These related documents provide the specific test procedures and sampling/description guidance that underpin D2487 classifications.

Keywords

USCS, Unified Soil Classification System, soil classification, Atterberg limits, liquid limit, plasticity index, particle‑size distribution, gradation, fines, gravel, sand, silt, clay, geotechnical engineering.

FAQ

Q: What is this standard?

A: ASTM D2487-17 is the ASTM practice that defines the Unified Soil Classification System (USCS) for grouping soils for engineering purposes; it assigns group symbols and names based on laboratory gradation and Atterberg limit results.

Q: What does it cover?

A: It covers the classification rules and charts for soils using particle‑size characteristics and the liquid limit/plasticity index. It explains when to use dual or borderline symbols, the sample portion to test (passing 3‑in. sieve), and the qualitative nature and limitations of the classification.

Q: Who typically uses it?

A: Geotechnical engineers, lab technicians, construction/materials engineers, site investigation teams, and regulators who need a standardised soil classification for reporting, specification, and preliminary engineering assessment.

Q: Is it current or superseded?

A: The D2487-17 edition (originally published in December 2017) is currently maintained and was reaffirmed/issued in 2025 as D2487-17R25 (ASTM records list a 2025 update/reaffirmation). Users should consult ASTM International for the official status and to obtain the latest published text.

Q: Is it part of a series?

A: Yes — it is part of the ASTM D18 committee suite of soil and rock standards (Book of Standards Vol. 04.08) and is frequently used in conjunction with related D‑standards that provide test methods and practices for soil description, sampling, and laboratory testing (for example D2488, D422, D4318, D4083, D3740).

Q: What are the key keywords?

A: USCS; soil classification; Atterberg limits; liquid limit; plasticity index; gradation; particle‑size distribution; fines; geotechnical engineering.