Abstract:
Various meso-scale representations of layered rock are formed by the directional arrangement and cementation of the minerals on a layered structure, which is obviously anisotropic in the mechanical behavior. This study presents a meso-scale particle discrete element model, which can demonstrate the meso-scale structure of slate by introducing a spatial correlation function. Based on the derivation of mechanical parameters on the meso-scale, the numerical simulations for slate Brazilian splitting tests with different bedding angles (
θ) are conducted to investigate the anisotropic behavior. The simulation shows that there are three typical failure modes due to the various arrangements of bedding structures, including tensile failure at
θ ≤ 30°, combined shear and tensile failure at
θ=45°~75°, and splitting-tensile failure at
θ>75°. The splitting tensile strength and the fracture energy decrease with the increase of
θ. The proposed method is able to describe the anisotropy characteristics and the deformation-fracture behavior for layered rocks, which is in a good agreement with corresponding experiments.