INVESTIGATING THE IMPACT OF VETIVER GRASS COMPOSITE WITH RICE HUSK ASH ON SOIL SHEAR STRENGTH: A BIOENGINEERING WAY OF SLOPE STABILIZATION

Abstract

The plant’s property of arresting the soil by roots reinforcement technique reinforces the slopes and increases stability. Using vegetation in bioengineering offers a viable slope protection solution. As a result of soil problems in environmental applications and effective solid waste disposal, research has been done to examine the feasibility of employing solid wastes to enhance soil engineering behavior. In this paper, the mechanical effect of vegetation and solid waste on slope stability is calculated by studying the effect of vetiver grass composite with rice hush ash on the stability of the soil. Laboratory tests were performed for soil, vetiver, and RHA (rice husk ash) composite. At different RHA content of 5%, 10%, 15% & 20% mixed in the soil on which vetiver grass was planted. According to the test findings, soil+vetiver+10%RHA gives the highest strength among different compositions. Soil+vetiver+10%RHA increased shear strength overall, decreasing cohesiveness from 15.37 to 13.10 KPa and increasing the soil friction angle from 33.22⸰ to 40.96⸰ . Based on the results obtained from the direct shear test, the factor of safety (FOS) was determined with and without a composite of vetiver and 10%RHA content by using PLAXIS 2D at different slope angles(A) of 30.960 , 36.870 , and 450 . A maximum percentage increase in FOS was observed at 18.78% for soil+vetiver+10%RHA with respect to bare soil at a slope of 45⸰ . This study offers a scientific explanation for the impact of plant and RHA cover on the stability of the slope.