Abstract: The constitutive relation of elasto-plastic zone is simulated by Mohr-Coulomb criterion (M-C), and the theoretical solutions of cavity expansion pressure and energy dissipation are derived. Based on the assumption of spherical cavity expansion, combining with energy theory and non-associated flow rule, the process of cavity expansion is regarded as an energy conversion problem, and the large-strain energy dissipation analysis of cohesive-frictional soils is carried out. Firstly, the elastic zone is analyzed by a small-strain theory. Then, considering the effects of elastic deformation and large strain in plastic zone, the relationship among cavity expansion pressure, energy dissipation and radius is obtained. Compared with the published results, the effectiveness of the study is verified. Finally, the effects of elastic deformation and large strain in the plastic zone on cavity expansion pressure and energy dissipation are studied. The results show that the cavity expansion pressure increases with the increase of the dilatancy angle, and most of the work done by the external force is transformed into energy in the plastic zone. The dilatancy angle has a significant effect on the change of the plastic zone and the cavity expansion pressure. With the increase of dilatancy angle, the radius of plastic zone and the cavity expansion pressure increase significantly. The energy dissipation analysis provides a new analytical method and necessary theoretical basis for understanding of the mechanisms of grouting, geotechnical test and driven pile.

Key words: energy dissipation, spherical cavity expansion, cohesive-frictional soils, large-strain