Analyses of embedded piles reinforced landslides using strength reduction finite element method

Abstract

Embedded stabilising piles for landslide reinforcement were proposed as a viable alternative to conventional full-length piles. Embedded piles are shorter than full-length piles, while still providing a sufficient factor of safety (FS) to landslides; however, the cost of embedded piles may be significantly less than full-length piles due to the smaller bending moment demand. The concept of effective length was introduced. A strength reduction finite-element model was developed for the analyses of embedded anti-slide pile-reinforced landslides. A method for searching for the optimum effective length and estimating lateral loads on piles was developed. A conceptual landslide reinforced with a single embedded pile was adopted to exercise the proposed method. Results showed that the FS increased with the pile length at the plastic limit failure state, the maximum bending moment of the pile increased significantly with the pile length. However, for a given design safety factor (target FS), the lateral load acting on the embedded pile was similar to that of the full-length pile. Finally, the proposed method was applied to stabilise a massive landslide using 18 embedded piles; field monitoring data implied that the performance of the reinforced landslide is acceptable.