DEFORMATION AND FAILURE OF SURROUNDING ROCK CONSIDERING WEAKENING OF MECHANICAL PARAMETERS UNDER SEEPAGE-DAMAGE-STRESS COUPLING

The study on seepage-damage-stress coupling of underground engineering rock mass is of great significance for the stability analysis of surrounding rock. This paper presents an improved model of seepage-damage-stress coupling based on elastic-plastic mechanics, seepage mechanics and damage theory. In this model, we fully consider the heterogeneity of rock mass, the dynamic weakening process of rock mass mechanical parameters, the post-peak characteristics of plastic yield of surrounding rock and the abrupt change of permeability coefficient in the process of damage. This model can better reflect the yield damage and progressive failure process of the surrounding rock, which is obtained from the analysis of numerical simulation results with the multi-physics coupling simulation software. In order to verify its validity, this model is used in the analysis of the progressive failure process of surrounding rock at different depths. The result is in good agreement with the results from the engineering practice.