3D Numerical Simulation of Horizontal Stress Influencing upon the Failure of Soft Alternating Stratified Roof Rock Mass

FLAC3D is adopted to simulate the variety laws of the plastic failure, displacement and stress of layered roof with constant vertical stress and changing side pressure. In this model, Two sides and bottom rock strata are more rigid, roof stratum is softer and stratification of rock mass is obvious. The mechanical parameters of every roof layers and softening joints are the same. The research results have showed that the failure laws are decided by the side pressure coefficient λ. When λ1, the scope of failure and unload pressure are larger, but the roof flexibility smaller. When λ≥1, the scope of failure and unload pressure are smaller, but the roof flexibility bigger.