PARTICLE FLOW CODE NUMERICAL SIMULATION OF UNIAXIAL COMPRESSION MECHANICAL BEHAVIOR OF GENTLY INCLINED LAYERED ROCK

Gently inclined layered rock masses display different mechanical behaviors at different strength of beddings in uniaxial compression tests. Particle flow code(PFC) is used to establish numerical models for uniaxial compression in gently inclined layered rock masses based on the results of laboratory uniaxial compression tests on protoliths. The variations in the strength and failure modes of layered rocks under different strength of beddings are characterized. The development and evolution of micro-cracks and meso particles' displacement during uniaxial compression in gently inclined layered rocks with different strength of beddings are analyzed. The results show that when the strength of beddings is far smaller than that of the intact rock between beddings, the beddings reduce the strength of overall layered rock mass to a certain extent. The macroscopic fracture surface is a polyline type surface along the beddings and through the beddings. When the strength of beddings is similarly equal to that of the intact rock between beddings, the macroscopic fracture surface is a smooth slope that obliquely passes through a number of beddings. When the strength of beddings is far bigger than that of the intact rock between beddings, the strength of the rock is mainly determined by the strength of the latter. The macroscopic fracture surface is a X-type conjugate failure surface.