American Society of Civil Engineers

Identification and Description of Soils Containing Very Coarse Fractions

by Fred H. Kulhawy, Dist.M.ASCE, (Prof., School of Civ. and Envir. Engrg., Cornell Univ., Hollister Hall, Ithaca, NY 14853-3501. E-mail: and Jie-Ru Chen, A.M.ASCE, (Asst. Prof., Dept. of Civ. Engrg., Natl. Chi Nan Univ., 1 University Rd., Puli, Nantou 545, Taiwan, R.O.C. E-mail:

Journal of Geotechnical and Geoenvironmental Engineering, Vol. 135, No. 5, May 2009, pp. 635-646, (doi:

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Document type: Journal Paper
Abstract: Current practices are reviewed for the identification, description, and classification of soils containing significant very coarse fractions. The review shows that there are serious shortcomings when these fractions are present. To upgrade current practices, improvements are needed in two areas: (1) the grain-size scale and nomenclature; and (2) the basic system for soil identification. First, an improved grain-size scale is proposed that clarifies the very coarse fractions and other nomenclature. Second, it is shown that current U.S. classification systems can not address the very coarse soils adequately, and they can not be adapted easily to do so. However, a relatively straightforward expansion can be made to the Burmister identification system to incorporate these soils. This Expanded Burmister Soil Identification System is flexible enough to describe and identify soils, ranging from very coarse to very fine, in a complete and consistent manner. Adoption of these two recommendations can improve practice and reduce current ambiguities in dealing with soils containing very coarse fractions.

ASCE Subject Headings:
Soil classification
Grain size
Coarse-grained soils
Soil properties