Fracture damage analysis on the stability of underground cavern

In the large underground houses group works, compression-shearing damage and tension-shearing damage make up of the main damage mechanism of surrounding rock mass during the course of underground houses excavating. In other ways, rock bolts have been widely used for rock reinforcement in civil and mining engineering for a long time. Bolts reinforce rock masses through restraining the deformation of the surrounding rock masses of underground houses. By the aid of the method of equivalent strain energy, the constitutive relation of anchored brittle discontinuous jointed rockmass is derived under the state of compression-shearing. The constitutive relation under the state of tension-shearing is also developed according to the theory of self-consistence. Finally, through 3-D FEM programming, the above constructive models (called FD model in the paper) are applied to actual project in the discontinuous jointed rockmass. The numerical results obtained by the numerical simulation of proposed FD model were compared with those of FLAOD simulation in order to verify the validity of the proposed models.