An Experimental Study on Slope Stability Using Bio-Engineering Stabilization

The Construction of infrastructures, imposed loading on slopes, and the level of rainfall around the world today have imposed a change to soil properties at a very high rate leading to the failure of road embankment slopes, buildings, and different structures around the world. This study seeks to find out whether vetiver grass root affects the stability of road embankment slopes. Laboratory tests conducted were Particle Size Distribution, Consistency Limit, Compaction Parameter, and Direct Shear Tests with the addition of 2, 4, 6, 8, and 10% vetiver root to the natural soil at different stages. The slope stability analysis was carried out using the Rocscience Slide2 v6.0 software considering the Liquid Equilibrium Method. The result from the st0rength test shows that there was an increase in the value of the angle of internal friction (ϕ) at 6% from 32 degrees (°) natural soil to 34.45° and a decrease in cohesion (c) from 8.89 Kilo Newton per meter square (KN/m2) to 6.62 KN/m2. The best results from the simulation were shown at 8% with variation in the factor of safety values from 1.487 to 1.493, 1.499, 1.507, 1.523, and 1.537 at 0.8, 1.4, 1.8, 2.4, and 2.9 m depth indicating the stability of the slope as the vetiver grass root increases in length and spreads deeper in the soil with time. The deeper the root, the safer the slope becomes. Therefore, vetiver grass root is a solution for stabilizing road embankment slopes with a 35-degree slope geometry or below.