Cyclic Behavior and Liquefaction of Sand Using Disturbed State Concept

A general constitutive modeling concept called the disturbed state concept (DSC) is developed in this research for the stress-strain and liquefaction behavior of saturated sands. The DSC model is a unified approach and allows hierarchical modeling for options like elastic and elastoplastic responses, microcracking, damage, and softening. The DSC model parameters for saturated Ottawa sand are evaluated using data from multiaxial tests. The model predictions are found to provide satisfactory correlations with the test results. The DSC model with the foregoing parameters is implemented in a nonlinear dynamic finite-element program (DSC-DYN2D). It is used to solve a typical boundary value problem—a shake table test—involving liquefaction behavior. Based on the results, it can be stated that the DSC model is capable of both characterizing the cyclic behavior of saturated sands and identification of liquefaction.