Application Research of Rock Mass Mechanics Parameter Estimation in Open-Pit Mines

The mechanical parameters of rock mass are significant in slope stability analysis of open-pit mines. Hoek-Brown strength criterion can fully reflect the characteristics of nonlinear failure of rock mass and it is widely used in engineering practice. Structural plane is a part of rock mass, and how to estimate the shear strength of structural plane in an exact way is also a worthy question to explore. The GSI index was quantified by the contour curve and pressure-resistance test. Using generalized Hoek-Brown strength criterion to calculate the mechanical parameters of the rock mass in Ⅱ-B slope of Hexing mine. According to the Barton-Bandis theory, the shear strength of structural plane and the stability of sliding rock mass were figured out. The calculation results showed that the safety factor of the slope is Fs= 1.285, and the safety factor of the potential slip plane is Fs= 0.911. That means the stability of the overall slope is well, but the partial rock mass has the potential to slip along with the structural plane. The analysis results are in accord with the actual situation. It is demonstrated that the strength parameters of rock mass and the shear strength of the structural plane obtained by this method are reasonable.