Burmister, Donald M.
Professor of Civil Engineering, Columbia University, New York, N. Y.
Pages: 16 Published: Jan 1953
The principal use of the direct shear test in soil and foundation work is the determination of the maximum shearing strength and angle of friction of soils for use in stability analyses. The angle of friction of a soil has been assumed to be an inherent property, which is not affected to any appreciable extent by the conditions imposed in the field during and subsequent to construction and by the test procedures used. The purpose of this paper is to show that it is most important to understand fully the fundamental concepts and mechanics of shearing phenomena and shear testing in order properly to make shearing tests and particularly to obtain and to use test results that have a direct and significant application to the stability problems under consideration. Consideration is given to the fundamental concepts of stress conditioning of the shearing strength characteristics of soils by consolidation under the initial stresses imposed upon the soils and to the character and influence of the stress and strain restraint conditions imposed in the direct shear test. A comparison is made with the probable restraint conditions inherent in natural situations and imposed by structures and construction operations. Applications are made which illustrate the necessity for and the practical importance and advantages of controlled test methods in direct shear testing.
Paper ID: STP47721S