Research and analysis on residual shear strength of surrounding rock base on elastic-plastic softening model

Abstract

The excavation of caverns caused the unloading of the surrounding rock, which decrease the strength of the rock mass. In this paper, an ideal elastic-plastic stress-strain softening model is used to analyse the shear strength sensitivity of the surrounding rock during cavern excavation, in order to research the relationship between deformation, stress, plastic zone and the strength parameters. The results show that the values of each shear strength parameter have a significant effect on the distance of the plastic zone, and the sensitivity of the plastic zone distance shows that the influence of peak internal friction angle, residual internal friction angle, residual cohesion and peak cohesion decreased successively.