Stability Evaluation of Reinforced Slope Soil with Vetiver Grass against Erosion and Landslides Hazards by Using Finite Element Method

Abstract

This work studied slopes with different geometric situations. The purpose is to select types of soil for embankment construction to stabilise the site by using nearby accessible filling materials. Then, PLAXIS-2D software was used including five (6) phases of sequential calculation such as soil, structure, mesh generation, conditions of flow and construction stage and the use of Vetiver grass for embakment stability reinforcement. Choices were made on soil properties, loading, water table effect, embankment geometry and reinforcement actions of vetiver grass. The method is based on using diverse filling materials and varied slope gradients with different heights. So, the slope analyse involves homogeneous soils, in addition to slope section by various soils strata. Results obtained showed that the increase in soil shear strength is related to the mechanical effects of vetiver roots and make the soil able to resist shear stress due to the presence of roots density within the soil mass and the root tensile strength. It is also noticed that the soil suction effects and roots reinforcement increased the apparent cohesion of the soil, showing an important role played by vetiver grass in stabilising shallow-seated slopes failure with significant effect on slopes stability.