Abstract: The strength reduction method is used in the finite element analysis (FEA) of a slope stability problem. The basic principles of the strength reduction method, physical meaning of the factor of safety, yielding criteria, selection of flow rules as well as the criteria for the slope failure are introduced in this paper. As an example of applying this method, the soil strength parameters used in the FEA for the slope stability problem are progressively reduced until the FEA cannot converge. The strength reduction factor that caused the divergence of the FEA is the factor of safety of the slope analysis. When a slope reaches equilibrium, the plastic strain, which is initialized at the toe of the slope, approaches the top of the slope. The reduction factor used in the analysis when a continuous plastic zone is developed can be treated as the factor of safety.

Key words: ANSYS software, Strength Reduction Method, Slope Stability, Finite Element Analysis, Factor of Safety