Journal of Advanced Research in Science and Technology
Volume 6, Numéro 1, Pages 897-907
2019-02-28

Effect Of Internal Erosion (suffusion) On Dikes Stability: Finite Element Analysis

Authors : Bouziane Abderrezak .

Abstract

In the present study a numerical solution is proposed in order to quantify the impact of internal erosion on dike stability. The mathematical model, consisting of erosion equations, mixture flow equations and stress equilibrium equations, is solved numerically by the finite element method using COMSOL MULTIPHYSICS software. The shear strength reduction technique is used to analyze the stability of a dike taking into account the effect of internal erosion. The variation in time and space of porosity, as internal erosion progresses, is chosen as a coupling parameter. We have considered that elasticity and soil resistance (cohesion) depend on porosity so that the material becomes weaker as porosity increases. The results show that the porosity increases significantly at the dike toe, which was explained by an erosion of this zone. Erosion at the dike toe induces alterations in the mechanical behavior of the medium. Since cohesion decreases with increasing porosity, the factor of safety of the downstream slope undergoes a significant modification. This study may help to better understand the phenomenon of internal erosion in dikes and to better prevent the stability of a hydraulic structure.

Keywords

Internal erosion ; Slope stability ; Factor of Safety ; Finite elements method