Reliability analysis of landslide stabilization with pile groups considering spatial variability of soil properties

Reliability analysis of reservoir bank landslides reinforced by multi-row anti-slide pile groups is significantly influenced by the uncertainty of soil parameters. This study focuses on the H1 landslide in Taping, located in the Three Gorges Reservoir (TGA) area. It proposes a random finite difference framework that incorporates the spatial variability of cohesion c and internal friction angle φ, based on random field theory and finite difference numerical method. The framework is employed to investigate how the spatial variability of cohesion c and friction angle φ influence the failure probability, reliability, displacement field, and maximum shear strain increment of landslide reinforced by anti-slide pile groups with 3-pile-diameter (P3d) and 5-pile-diameter (P5d) row spacing. The results demonstrate that the spatial variability of soil parameters significantly influence the reliability of H1 landslide. Moreover, it also substantially affects the displacement, bending moment, and shear force of anti-slide piles, while exerting a certain influence on the landslide displacement field and shear strain increment. The increase of coefficients of variation and scale of fluctuation result in a marked decline in landslide stability coefficient, raised failure probability, and reduced reliability. The reliability of the P3d landslide is superior, exhibiting a reduced failure probability compared to the P5d. In addition, the P3d landslide demonstrates greater overall displacement, bending moment, and shear force, resulting in enhanced landslide stability. As a result, the P3d pile group provides more effective reinforcement for the Taping H1 landslide and could therefore be regarded as a valuable reference for its protection and mitigation.