3D Elastoplastic Model for Crushable Soils with Explicit Formulation of Particle Crushing: Fid-Bau Portal

3D Elastoplastic Model for Crushable Soils with Explicit Formulation of Particle Crushing

Liu, Mengcheng

AbstractAn extended version of the coupling breakage and friction dissipation (CBFD) model is developed based on the critical state concept for crushable soils. In the extended CBFD model, the single-parameter function is adopted to characterize the continuous grading of crushable soils, and an inherent relationship is constituted among the grading constant, breakage index, and plastic work or mean effective stress according to the corresponding physical meaning, and a critical state breakage is introduced as an extra dimension in the formulation of critical state void ratio or stress ratio to reflect the effect of particle crushing on the critical state behavior. There exists an inherent link of the grading evolution, particle crushing, and shear behavior in this model. The proposed model is extended into a three-dimensional (3D) stress space and accounts for the Lode angle–dependent strength behavior. Numerical analyses are carried out for a series of (true) triaxial tests on various crushable soils (i.e., sand, gravel, and modeled rockfills), and the model prediction coincides with the experimental trend. The investigation indicates that the proposed model is capable of reproducing the highly nonlinear shear behavior (upon shearing and in the critical state) and even the inherent grading evolution of crushable soils.