A Study on the Influence of Vegetation Growth on Slope Stability

Abstract

Vegetation plays a major role in terms of slope stability. Roots of grass and trees can increase the strength properties of soil which improves the stability of slope. A natural slope consists of grass and infinite number of trees inclined in different directions along with inclined roots. The aim of the paper is to study the effects of vegetation growth on slope stability for different root reinforced soil depth by varying tree inclination (along with roots), root spread and tree spacing for different slope geometry. The study involves determination of safety factor (FOS) of natural slope existing with and without vegetation growth (such as only grass, grass and trees). GeoStudio Slope/w software with limit equilibrium method was used for stability analysis of different slope inclinations. A tree was modelled as a point load and its roots were represented as reinforced soil properties with anchors and only as root reinforced soil. When compared to the bare slope, it was observed that there was an increase in FOS of slope on both the models of vegetation. Variations in FOS by varying root reinforced soil depth, tree inclinations and spacings were reported for different slope geometry and compared. Considering all these parameters, an empirical corelation for computation of vegetation influenced FOS has been developed. This study provides a mechanical accountability of vegetation cover on the stability of slopes.