An Anisotropic Constitutive Model for Crushable Geomaterials Based on Non‐Stationary Critical State Line Concept

ABSTRACT In this paper, the dependencies of granular soil behaviour on particle crushing and fabric anisotropy are formulated within a novel model based on bounding surface plasticity theory enriched by the non‐stationary critical state line (NCSL) concept. By introducing a flexible decay function, the variation in the position and slope of the CSL with the magnitude of particle crushing is regulated. The originality of the model extends beyond its ability to capture the pre‐ and post‐failure behaviour of crushable geomaterials, as the elastic moduli are also modified to depend on both the stress state and the extent of particle breakage. The capabilities of the model are demonstrated against published data from triaxial compression tests on the widely studied Cambria sand and a compacted coal wash reject material from Australia. It is shown that the proposed model consistently captures the behaviour of crushable geomaterials across a wide range of void ratios, stress levels and particle breakage states, using a unified set of parameter values. The formulation of this anisotropic model has been kept sufficiently simple to facilitate its straightforward future implementation into a continuum‐based numerical framework for boundary value problem simulations.