A MODEL FOR UNDRAINED CYCLIC SHEAR DEFORMATION BASED ON THE EFFECTIVE STRESS PATH AND THE ACCUMULATIVE SHEAR WORK

Abstract

A model for cyclic shear deformation under undrained condition is proposed as combining an effective stress path model with a nonlinear stress-strain curve. The effective stress path, which is given by a function of stress ratio with a harmony of two terms corresponding to positive and negative dilatancy, can express the cyclic mobility without using the phase transformation line. In order to couple to the nonlinear stress-strain curve with the effective stress path, the residual excess pore pressure buildup under undrained cyclic stresses is formulated as a function of accumulative shear work, which depends on the initial shear stress for sand and the strain-rate & strain amplitude for clay.