Stability Analysis of Unsaturated Slopes Considering Combined Influences of Strength Non-homogeneity and Non-saturation

In the present study, the stability analysis of slopes in four different categories of non-homogeneous and anisotropic soils under various steady flow conditions, i.e., infiltration, evaporation, no suction and no-flow are conducted based on the limit analysis method. The internal energy dissipation owing to soil cohesion considering non-homogeneity and anisotropy, as well as the rate of work done by the apparent cohesion resulting from matric suction are calculated. Thereafter, the analytical expression of the required cohesion and stability number of slope are derived in virtue of the energy balance equation. The optimized solutions are obtained using the optimization program. The results are compared with those of a previous study to verify the present work, and a parametric analysis is conducted to investigate the effects of cohesion strength non-homogeneity and anisotropy of cohesion strength, infiltration rate, slope geometry, and soil type on slope stability. It is found that cohesion non-homogeneity and anisotropy have significant influences on slope stability of slope subjected to the no-suction condition, and variation in steady flow conditions hardly change the effect of slope angle on slope stability. A set of numerical solutions to obtain preliminary designs is presented in Sect. 7.