Evaluating the performance of soil nailing in slope stability under complex conditions

Abstract

Soil nailing has become a widely adopted slope stabilisation technique designed to enhance the structural integrity of soil and rock masses, particularly in earthquake and landslide-prone regions. It has effectively stabilised both natural and man-made slopes by preventing erosion, settlement, and various forms of slope failure, while also reinforcing existing foundations, etc. In this paper, to investigate the effect of soil nailing on slope stability, a two-dimensional finite element method (2D-FEM) was utilised to simulate four distinct slope conditions: Case-I (no surcharge, no nails), Case-II (surcharge without nails), Case-III (surcharge with nails), and Case-IV (nails without surcharge). This study has introduced a numerical framework that examines plastic equivalent deviatoric strain, plastic strain along the x- and z-planes, and plastic shear strain to comprehensively assess displacement behaviour under varying conditions. The results have shown significant reductions in displacements along the x-direction (d_x), z-direction (d_z), and the resultant displacement magnitude (|d|), particularly in Cases III and IV. Furthermore, the analysis has taken into account several environmental conditions: (A) without groundwater table (GWT) and seismic loading, (B) with GWT but without seismic loading, (C) without GWT but with seismic loading, and (D) with both GWT and seismic loading. Across all scenarios, the incorporation of soil nails significantly improved the factor of safety (FOS), whereas increasing the slope angle from 30° to 90° relative to the horizontal plane correspondingly decreased the FOS, indicating a critical balance between slope inclination and stability. Overall, this study has demonstrated the effectiveness of soil nailing in enhancing slope resilience and has provided comprehensive insights into its performance under diverse environmental and loading conditions.