Safety factor analysis of natural slopes using Rigid Plastic Finite Element Method (RPFEM)

In this study, a new method for analyzing safety factor (Fs) of natural slopes was developed. Rigid-plastic constitutive equation for soil materials and a slope stability analysis framework were formulated to account for both soil properties (cohesive strength c and friction angle f) and slope geometry (slope angle β and slope height H). These models enable the analysis of cohesive and frictional strengths within slopes while avoiding the need for excessive element subdivision, thereby allowing for high-precision analysis. To demonstrate the effectiveness of the developed model, its validity was first verified through numerical analysis of simple models with known solutions. The results indicate that this method can reasonably evaluate the stability of slopes across a wide range of soil properties and geometric conditions.