The use of Vetiver grass and nails for slope protection against erosion and landslide risks

Abstract

Slope instability occurs practically all time in Brazzaville City, Congo Republic. Extreme precipitation throughout rainy seasons from September to December and from March to May escorted by construction works in dangerous areas are the main origins of slope instabilities. Intact samples of soil were taken since two diverse sites of Brazzaville City for experimental study, using laboratory tests in order to find soils engineering properties. After laboratory tests, the soils were categorised as silty sand (SM) and clayey sand (SC) respectively. Slope Model of Finite Element was created for the slope stability study using Plaxis 2D software. The increment of Vetiver root profundity increased the slope resistance against erosion and landslide a little for sand clay (SC) as a result of the base rupture found profoundly. Audaciously, Vetiver grass is considered further active for silty sand with large increments of slope safety factor. Moreover, nailing alongside with vetiver increment slope resistance against erosion and landslide for silty sand (SM) more than in sand clay (SC) associated to slopes in bare state. Later, the mutual accomplishment of nailing and Vetiver can constitute an active action for preventing erosion and landslide risks.