Abstract: The inhomogeneity of layered rock mass is mainly contributed by the inhomogeneity of bedrock and the inhomogeneity of bedding plane joints. It is important to consider the different homogeneity of bedrock and bedding plane joints. Therefore, this paper combines the WLPB model and the WSJ model to characterize the inhomogeneity of bedrock and bedding plane joints, respectively. We put forward a new theory and calculation method of micro-inhomogeneous contact mechanics model of bedded rock mass, and analyze the deformation characteristics, failure modes and micro-evolution laws of bedded rock samples under uniaxial compression. The results show that the elastic modulus, peak strength and failure mode of layered rock samples present obvious anisotropic characteristics, which are in general consistent with the laws of laboratory tests. It demonstrates the rationality and adaptability of the developed inhomogeneous microcosmic contact model of layered rock mass. When the mechanical behavior of layered rock mass is controlled by the bedding plane, the inhomogeneity of bedding plane becomes an important factor affecting the macromechanical characteristics of layered rock mass. When the bedding plane plays a controlling role, the influence of bedding plane spacing is not obvious on the peak strength of layered rock samples, but it is obvious on the deformation characteristics of rock samples. The paper reveals the micro fracture mechanism and transformation law controlled by the inhomogeneity of bedding plane of layered rock mass with different inclination angles under uniaxial compression.

Key words: layered rock masses, discrete element method, WLPB model, WSJ model, inhomogeneity