A Novel Simple Solution to Cavity Expansion Problem in Crushable Granular Materials Based on Energy Dissipation Method

This study presents an energy dissipation analysis approach for cavity expansion problems in crushable granular materials under the high stress state. By assuming that the energy dissipation generated from cavity expansion is mainly absorbed by the volume strain deformation in the plastic region, the energy conservation equations of the volume changes and energy dissipation in the plastic region during cavity expansion are reconstructed based on the compression failure mechanism. The limit pressure of the cavity expansion under high stresses is obtained based on a new critical state line for the crushable granular materials and the energy dissipation analysis method. The proposed approach is validated by the existed results. The effects of the initial void ratio and stress for the crushable granular materials on limiting expansion pressure of cavity expansion are investigated particularly. The results show that the effect is proved to be significant and must be considered in the analysis of cavity expansion problems, particularly for crushable granular materials at high stress.