Particle breakage energy and stress dilatancy in drained shear of rockfills

Particle breakage can be quite considerable even at low-stress levels, and it has a significant influence on the stress dilatancy of rockfill materials. In order to reasonably quantify the energy consumed by particle breakage, which has yet to be satisfactorily addressed, a function of friction ratio relating to the distortional strain and critical state stress ratio is proposed in this paper. The friction ratio references the widely accepted evolution rule of particle breakage and the new calculated energy consumption by particle breakage is proved to result in a reasonable distribution against increasing strain. Then, the rate of energy consumption per unit volume of aggregates is certified and suggested to be a linear relationship with the proposed friction ratio. Additionally, a stress dilatancy relationship for rockfill materials, based on modified Rowe's dilatancy law, is derived and verified by successfully predicting the stress dilatancy of drained rockfill triaxial specimens. It is believed to be an effective stress dilatancy for the study of elastoplastic constitutive model of rockfill materials.