Stability analysis of anchored slopes based on a peak shear-strength criterion of rock joints

A new three-dimensional shear-strength criterion (3DSSC) considering the three-dimensional (3D) roughness of rock joints and the internal friction angle of rock masses is discussed. Two methods for transforming the parameters of the 3DSSC into the linear Mohr–Coulomb failure criterion parameters are proposed. The calculation method of the anti-sliding safety coefficient of a rock slope controlled by a single anchored rock joint is derived, and anchoring parameter analysis is carried out. Compared with the equivalent linear fitting method and tangent equivalent method for obtaining the Mohr–Coulomb shear-strength parameters, the 3DSSC can be directly applied to calculate the rock slope stability controlled by a single rock joint. The change in the characteristics of the anti-sliding safety coefficient of the slope with the changes in the 3D roughness parameters, shear rate, and internal friction angle are discussed. The sensitivity of these factors to the slope stability is analyzed. It is suggested that for rock slopes with high roughness and a small internal friction angle, the weakening effect of the anchoring force angle on the anti-sliding stability of the slope should be taken into account.