Optimization of failure surfaces for toe slide in homogeneous finite slopes

Slope is called as the surface of the soil or rock masses which has an inclination to the horizontal plane. Slope stability is defined as the structural performance that is exhibited against sliding or collapse due to dead and additional loads. Recurrent basic approach in slope stability analysis is to determine the minimum factor of safety by searching the most critical failure surface. In this study, a novel method was developed by modifying the Generalized Janbu Method for toe slide of homogeneous finite slopes. The developed method can take into account all possible types (composite) of failure surfaces. The most critical failure surface that provides the minimum factor of safety is determined by using a program developed in MATLAB programming language based on optimization method. Ultimate factor of safety was found for the obtained most critical failure surface by doing sequential computations of safety analyses. Then, failure surfaces and factors of safety were obtained for different c, Ø, and β values in homogeneous finite slopes by making slope stability analysis. From the results of performed analyses with the developed method, it was seen that the obtained sliding surfaces, which are different from circular surfaces, have composite structures consisting of different types of curves. Lower factors of safety were obtained the method developed in this study compared to the methods based on circular failure surface assumption because of including all failure surface possibilities.