Analysis of Safety Factor on Shallow Slope Stability due to Grass Water Uptake

Abstract

Shallow landslide is the geotechnical problem-based slope collapse phenomenon that often occurs in tropical rainforest regions such as Malaysia. It is a prevalent geotechnical concern facing slope engineers. In residual soil slopes, there are several variables that trigger landslides, and rainfall has been the cause of most landslides in regions experiencing high seasonal rainfall. This research examined the slope stability protection factor due to grass water uptake for six types of grasses. As a geosynthetic mesh, the fine root distribution for grass with a clear and easily established depth plays an important role by providing obvious enhanced stability that enhances the soil's strength. Six grasses, namely Axonopus Compressus, Pennisetum Purpureum, Andropogon Gayanus, Brachiaria Humidicola, Melinis Minutiflora and Digitaria Eriantha were used in this research. At a depth of 0,1,2,3,4 and 5 m, the pressure head for the six types of grasses involved was measured. The protection variables for all grasses vary from 2.8800 to 3.1860. A value greater than 1 reflects the slope's stability. When assessing the importance of this safety factor, the amount of moisture content plays a crucial role. This study strongly believes that Axonopus Compressus grass with a protection factor of 3.0670 absorbs water more easily than others and is helpful in maintaining unsaturated soil stability.