Improvement of the finite-element-based limit equilibrium method to include changes in groundwater: a case study of a deforming bank slope from the Three Gorges Reservoir

Abstract

Changes in groundwater are an important factor affecting slope stability. In this study, the finite-element-based limit equilibrium method (FELE), which does not require any predetermined assumptions, is improved to include groundwater. The seepage force in the improved FELE is directly regarded as a body force and can be transformed into the equivalent nodal force. Moreover, a practical technique of employing the signed distance function is used to represent the groundwater level, making the improved FELE insensitive to the mesh. An analysis of a benchmark slope is performed to validate the effectiveness of the improve FELE, and the results show that the seepage force has a significant influence on the stability of the slope. Moreover, a case study of a deforming bank slope from the Three Gorges Reservoir is analyzed by the improved FELE to study the relationships between the deformation and changes in the phreatic lines within the sliding body.