Cyclic mobility response of a dense sand stratum

Abstract

The cyclic mobility response of a dense sand stratum is examined using a semi-empirical effective stress model. The model is based on two families of intersecting yield loci, one for loading and the other for unloading. The yield loci are generated from Cam Clay type energy balance equations and the associated flow rule. Comparison of model with observed behaviour in cyclic simple shearing indicates that, although the model is unable to reflect the full spectrum of sand behaviour in cyclic loading, the salient features of cyclic mobility behaviour are adequately represented. The model is then applied to the problem of an infinitely long, sloping, saturated dense sand stratum subjected to base excitation. Comparison of computed results with centrifuge data shows that the model is able to explain much of the observed behaviour in terms of the interaction between soil skeleton, pore water and propagating shear waves. Such interaction is not fully considered in existing methods of designs. © 1991.