IRRECOVERABLE AND OVERALL STRAINS IN CYCLIC SHEAR OF SOFT CLAY

Abstract

A series of cyclic loading tests was performed on undisturbed marine sediments of the Israeli continental slope. Testing was carried out in a torsional hollow cylinder device under a variety of boundary conditions, as well as in a direct simple shear apparatus. Analysis of the test data leads to the hypothesis that cyclic shear strains may be divided into irrecoverable and overall components, and that the relationship between the two takes the form of a continuous, increasing function. This function is independent of the applied boundary conditions, testing equipment and strain rate, but is dependent upon the particular soil. The relationship for the soft clay tested in the present study was found to be linear. Data published by other researchers validates the proposed hypothesis. It appears that for any particular soil, the same relationship is valid for uniform stress or strain controlled loading, as well as for irregular loading sequences.