Evaluation of Slope Stability Due to Rain Infiltration (Case Study: National Road Connecting Enrekang and Toraja Regency)
Deyva Anggita*, Fikri Faris*
*Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia
*Corresponding author: fitrisubhan0778@gmail.com
INTISARI
Landslides are one of the natural disaster phenomena that cause the most casualties, infrastructure damage, and economic losses. One example is the landslide case that occurred on the national road connecting Enrekang Regency and Tana Toraja Regency. This road section is the main access for people who want to pass from Makassar to Tana Toraja Regency. The landslide that occurred resulted in a long traffic jam from both directions, disrupting the economic activities of the community, to traffic accidents. According to local residents, the landslide phenomenon on this road section occurs almost every year, especially when the intensity of rainfall is high. Landslides can be triggered by several factors such as geological structure, morphology, regional climate, and geotechnical properties of surface rocks. The purpose of this paper is to know and understand the factors that trigger landslides at the research location and the appropriate handling. The information used in the research is in the form of soil data from drilling at 2 points, geophysical surveys on 3 tracks, and laboratory testing of several soil samples taken from the research site. The landslide at this location occurred gradually, starting from the subsidence of the slope soil at the edge of the road body and the collapse of the road body surface. Within a period of 4 – 5 months, three landslides can occur, namely in December 2022, March 2023 and May 2023. The analysis shows that the clay soil material, which is the type of soil at the research site, is the controlling factor for landslides triggered by high rainfall intensity. Infiltration of rainwater through soil fractures resulted in a significant increase in water content, the load on the slope soil increased, triggering landslides. In this research, an analysis will be conducted using the Limit Equilibrium Method to determine the condition of slope stability due to factors that trigger landslides.
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