Liquefaction Potential of Dams and Foundations. Report 3. Development of An Elastic-Plastic Constitutive Relationship for Saturated Sand.

摘要

This report describes the initial attempt at developing a three-dimensional constitutive relationship for saturated sand. An isotropic constitutive relationship has been constructed, within the framework of the incremental theory of plasticity, that qualitatively simulates some of the features of the stress-strain-pore pressure response of saturated sand. It accounts for the hysteretic behavior of pressure-volumetric strain response of sand, the effect of superimposed hydrostatic stress on shearing response, and the shear-induced volume change. It does not, however, treat strain-softening behavior and does not predict progressive increase of pore pressure under low-amplitude (subyield) cyclic loading conditions. The behavior of the constitutive relationship under conventional undrained triaxial test condition is examined and correlated with experimental data for saturated Reid Bedford Model sand. A recommendation is made that the present constitutive relationship be extended to quantitatively simulate the basic features of the stress-strain-pore pressure response of saturated sand, including the strain-softening behavior and the progressive increase of pore pressure observed under cyclic loading conditions.