Numerical simulation of failure process of overburden rock strata caused by mining excavation

Dynamic progressive process of failure of overlying rock strata caused by mining excavation is simulated by Strata Failure Process Analysis （SFPA 2D） system. The numerical simulation result reproduces the whole progressive process of vertical discontinuous displacement, bending, sagging, fracturing and caving of overlying rock strata. It also reproduces the evolution of the stress and strain fields as the working face advances. Fracture mechanism is discussed based on the numerical simulation result. It is pointed out that failure characteristic of overburden strata is influenced by stress redistribution and accumulated damage,which are induced by step excavation, and the heterogeneity of rock stratum.