Simple Double‐Hardening Model for geomaterials

Abstract

A simple approach for nonassociative elastoplastic modeling of mechanical behavior of soils is presented in this paper. The distinctive features of this model are: (1) Disparate mechanisms for volumetric and distortional yielding; (2) plastic flow functions similar to those employed in the original cam‐clay models; (3) yield stresses given by single state variables; and (4) hardening moduli controlled by the evolution of a state variable. The capability of the model in its present form has been assessed against common triaxial (monotonic loading) test results obtained from published sources. Many complex characteristics of granular soils such as mean stress and path‐dependent dilatancy, strain‐hardening and strain‐softening responses in drained shear, and density‐dependent undrained shear responses (complete liquefaction as well as cyclic mobility) are remarkably well reproduced by this approach.