水平应力对巷道软弱互层顶板岩体破坏的数值模拟研究

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

运用数值分析,对垂直应力不变条件下改变水平应力对巷道软弱层状顶板岩体的塑性破坏、位移和应力变化规律进行了三维数值模拟。巷道两帮和底板岩层较硬,顶板岩层相对软弱,并且层理发育。顶板各岩层及软弱夹层的物理力学参数分别相同。研究结果表明,层状顶板岩体的破坏特征是由侧压系数λ决定的。当λ<1时,顶板的塑性区和卸压范围较大,但顶板挠度却较小。当λ>1时,顶板的塑性区和卸压范围较小,但顶板挠度却较大。

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 λ<1, 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.