Comparison of slope stability using Smoothed Particle Hydrodynamics, Finite Element Method, and Limit Equilibrium Method


The principles of slope stability analysis embrace the mechanics of slope failure to develop methods of stability analysis, to predict factors of safety and corresponding slope movements. By equating the disturbing and resisting forces on potential slip surfaces, Limit Equilibrium method computes the corresponding factor of safety. These static stability methods can be used to calculate the minimum factor of safety, but they cannot predict pre and post-failure movements of the system in case of failure. As an advanced numerical method, Finite Element method and the strength reduction technique takes into consideration the stress distribution within the slope. This stress distribution controls the deformations, movements, and development of failure zones for a given slope. Along with the factor of safety, FEM also predicts these expected deformations/movements. These deformations in FEM are dependent heavily on the meshing of the whole system and suffer from mesh distortion and low accuracy in case of run-out/ flow analysis where mesh deformations are relatively more significant. Run-out/flow failures (landslides, landfill failures) where the debris flows over a great distance, have been a prominent research topic for many years. Numerical methods have been developed such as the Center of the Mass method, FEM with updated mesh techniques, DAN/W, Meshless Methods (SPH, DEM, and DDM). Smoothed Particle Hydrodynamics (SPH) is a meshless technique which discretizes continuous material into discrete particles. When combined with a yield strength, SPH solves Navier Stokes equations to predict the slip surfaces as well as run-out/flow of the slope. In this study, a comparison has been made between LEM, FEM, and SPH on slope failures taken from literature. The slip surfaces as obtained from these slope failures have been compared, and the deformations have been studied between FEM and SPH. The advantage of SPH in predicting flow failures has been highlighted.

In Indian Geotechnical Conference 2018, IISc Bangalore, India TH-03-31