Multiple arching in cohesion–friction soils: Insights from deformation behavior and failure mechanisms using FEM-SPH approach

Abstract

Soil arching is a common phenomenon in many underground engineering problems. This paper develops a coupling approach involving the Finite Element Method (FEM) and Smoothed Particle Hydrodynamics (SPH) method to investigate the multiple soil arching effects of cohesive–frictional soils. This approach is proved to be successful in capturing multiple soil arching by comparing the numerical results with experimental observations. Then, a sensitivity analysis is carried out to reveal the influence of geometric and material parameters on load transfer, deformation behaviors, and failure mechanisms. From a microscopic point of view, the mobilization of soil particles is analyzed to explain the formation of multiple soil arches. The failure mechanisms are characterized by two types of failure surfaces formed above the trapdoors and the rigid bases, respectively. The key factors that influence the interaction between adjacent soil arches are identified by analyzing the inclinations of the failure surfaces. The evolution of the equal settlement plane and failure surfaces during the arching process is also discussed.