Tensile strength of slate based on Heok-Brown criterion

The slate and other layered rock often have a variety of structural surfaces, and the tensile strength of the rock mass enjoys greater difference under different levels of inclination. To reveal the tensile strength anisotropy of slate, a formula for the tensile strength of disc change of bedding angle βis derived based on the Heok-Brown criterion and analytical solution of the elastic mechanics for Brazilian disc plane stress. According to the results of uniaxial and Brazilian splitting tests on samples with different bedding angles β, the following goals are achieved: the parameters of the formula for the tensile strength, the compressive strength of anisotropic degree between 3.94 and 4.87, the tensile strength of anisotropic degree between 2.86 and 3.15, and the trend of compressive (tensile) strength which reaches the maximum value in the middle and the minimum one at the two sides. In addition, the derivation of the proposed formula can explain the relationship between the tensile strength and the bedding angle. This work may provide some reference for layered rock in similar tensile state.