Limit equilibrium solution for the rock slope stability under the coupling effect of the shear dilatancy and strain softening

Abstract

In addition to obeying the generalized Hoek-Brown (GHB) strength criterion, the shear behavior of the rock mass sometimes has the effect of the shear dilatancy and characteristics of the strain softening. However, the traditional limit equilibrium (LE) methods can only solve the slope factor of safety (FOS), and it is difficult to calculate the displacement of sliding body (DOSB) of slope. Therefore, it is rarely reported that the LE analysis on rock slope stability under the coupling effect of the shear dilatancy and strain softening. Here, referred to the effect of the shear dilatancy and characteristic of the strain softening for rock mass, the calculation model for slope DOSB is constructed. Then, based on the assumptions of the stresses on the slip surface, the LE solution for rock slope stability is established according to the mechanical equilibrium conditions satisfied by the sliding body. Meanwhile, the calculation formula of slope DOSB is derived by introducing the energy balance equation of sliding body for the slope with the small sliding displacement. Further, the iterative loop calculation strategy is given to solve the slope FOS and slope DOSB for achieving the purpose of quickly obtaining the implicit solution. By comparison and analysis on some slope examples, the feasibility of the present method is verified. Compared to the traditional LE methods, the present method can not only analyze the stability of rock slope under the nonlinear strength criterion, but also study the influence of the shear dilatancy and strain softening of rock mass on the rock slope stability.