Finite element analysis of slope stability using a nonlinear failure criterion

Nonlinear shear strength criteria of power-law type are implemented in a finite element slope stability analysis. Numerical solutions in which failure mechanisms can also be estimated are favorably compared to those obtained using limit analysis and limit equilibrium approach. Emphasis is made on the definition of two different stability numbers. One has been employed by some authors in the context of rock slopes and the other is commonly used in soil mechanics. Depending on how the factors of safety are defined, the stability numbers computed using the two definitions may be different, and so the design charts prepared in each approach should be assessed with caution. Earthquake effects are also analyzed by pseudo-static considerations. Stability numbers for different seismic coefficients are computed and compared with other existing solutions. If Newmark’s displacement approach is used, calculation of earthquake induced deformations is highly sensitive to stability analyses and thus to the assumption on failure mechanisms, and so a finite element analysis provides advantages over other methods because no failure mechanism has to be assumed a priori.