SELECTION OF WILD PLANT SPECIES AS SOIL BIOENGINEERING FOR SOIL SLOPE STABILITY IN SOUTH KALIMANTAN TO OVERCOME SHALLOW LANDSLIDES

Abstract

Soil Biotechnology is a cost-effective and environmentally friendly alternative method to improve soil slope stability, as well as to control slope surface erosion. Vegetation, which is part of soil bioengineering, can indirectly affect slope stability through its influence on fluctuations in soil water content. Furthermore, it has the ability to control the adverse effects of rainfall on the slope surface and can draw water from the soil through evapotranspiration. These conditions can reduce soil moisture and pore pressure, increase soil shear strength, and increase resilience. Vegetation roots tend to increase soil permeability, infiltration, and moisture content. In this research, vegetation was used for soil bioengineering in the form of plants that grow wild and are easily found in the mainland of South Kalimantan Province, in Indonesia. These plants include Teki, Paitan, Elephant, Setaria, and Alang-alang grasses. This research aims to determine the effects of different plants and their root types on the surface of the soil slope, especially to determine changes in the value of the soil shear strength, the resisting moment of slope failure, and the safety factor of the slope's stability. Accordingly, soil testing and the analysis of slope stability were carried out using the direct shear test and the Bishop methods respectively with the help of the 2022 version of the Geo5 computer application program. The results showed that the use of Elephant grass vegetation on the slope surface was able to increase the shear strength of the soil, the landslide resisting moment, and the safety factor for slope stability which was better than other types of vegetation.