Constitutive Modeling for Two Sands under High Pressure

Particle breakage is a typical characteristic of crushable granular soil under high pressure, which has great effects on its stress–strain behaviors. The phenomenon of the critical state line (CSL) shifting downward in the compression plane caused by particle breakage was depicted by a breakage-dependent critical state plane (BCSP). Particle breakage was incorporated into a void ratio–pressure state parameter to modify Rowe's stress–dilatancy equation, and then, the state parameter was incorporated into the bounding stress ratio and plastic modulus. Due to the impact of high pressure on particle breakage, the pressure-dependent plastic modulus parameters were introduced. A breakage-dependent bounding surface plasticity model was proposed to capture the influence of particle breakage on the state-dependent stress–strain behaviors for silica and coral sands, and the transition of complex breakage-dependent critical states resulted from the competition between the contraction due to particle breakage and the dilatancy due to particle rearrangement.