Endochronic constitutive model for soil. Final report

This report describes the formulation and application of a new three-dimensional, nonlinear constitutive model for soils. The model is developed within the general framework of the Endochronic theory of plasticity with singular kernels, and incorporates basic concepts of critical state soil mechanics. Because of its ability to realistically represent the hysteretic behavior of soils during repeated unload-reload processes, the model is particularly useful for describing the response of soils to earthquake-type loading. Applications of the model to monotonic and cyclic multi-axial data for several drained soils are presented, and comparisons between predicted and measured responses are given.