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.