Analysis of conventional and helical soil nails using finite element method and limit equilibrium method

Heliyon. 2022 Nov 17;8(11):e11617. doi: 10.1016/j.heliyon.2022.e11617. eCollection 2022 Nov.

Abstract

The infrastructure of roads, bridges, tunnels, subways, etc. is grooming day by day. In the recent era, soil nailing is the developing method for slope stability, road widening projects, and constructing deep foundations. This paper suggests a new and improved helical soil nail (HN) that offers an alternative to conventional soil nail (CN). Till now pullout studies on different model nails in c-Φ soil are still rare. In addition, the stability analysis for conventional soil nails was only studied using FEM analysis, whereas for helical soil nails the estimation of stability of slope is still mysterious. So, the present study includes the behavior of conventional and helical soil nails based on both laboratory and analytical methods in c-Φ soil. The present study also incorporated the use of theoretical equations and finite element analysis (using PLAXIS 2D) for comparing the stability of different profiles of soil nails (e.g., CN and HN) in c-Φ soil, which was unique to this study. By using the finite element method (FEM) and the limit equilibrium method (LEM), a factor of safety was also estimated for both types of nails (CN and HN). According to the experimental, analytical, and numerical findings, it is clear that helical soil nails (HN) exhibit less deformation and more factor of safety than conventional soil (CN) nails under similar loading and soil conditions.

Keywords: Conventional soil nail; Finite element method; Helical soil nail; Slope stability; Soil nailing.