Elastoplastic constitutive model of coral sand considering particle breakage based on unified hardening parameter

Abstract

Particle breakage is a significant phenomenon that distinguishes coral sand from other granular materials. This study aims to build an elastoplastic constitutive model which can describe the mechanical behaviour of coral sand at different relative densities and confinement conditions. According to the results of triaxial compression test and isotropic compression test, the expression of the critical state line (CSL) considering particle breakage and a new hardening rule based on unified hardening parameter was proposed, respectively. A shape parameter of yield surface which incorporates the impact of particle breakage and relative density simultaneously was defined. Then, an elastoplastic constitutive model of coral sand considering the particle breakage and relative density was established by introducing the new hardening rule and the shape parameter. By comparing the results of triaxial compression tests with that of the elastoplastic constitutive model, the model was proved to be able to predict the mechanical behaviour of coral sand at different relative densities and confining pressures.