Landslide Analysis Study and Cisewu Countermeasures in District, Garut Regency, West Java

Abstract

Cisewu-Garut is one of the landslide-prone areas in Indonesia which occurs almost every year, particularly in the rainy season. The landslide in this study takes place in the slope where a BTS tower is located. The peripheral fence is hanging due to ground movement, while housings stay beneath the foot of the slope. This problem could harm its surroundings and needs immediate countermeasures to prevent any hazard. At the initial stage, a survey is conducted to investigate slope condition, soil state (including soil test), and drainage. Based on available soil data, the second stage is slope stability analysis by creating a model corresponding to real condition data using the element method to Plaxis2D software. As for the third stage, a landslide disaster prevention is established by strengthening the foot of slope using gabion and retaining walls. The gabion wall cage dimension would be 5m wide and 2.5m tall. Two retaining walls by the size of 2m high to 1m wide and 1m high to 0.6m wide are build. The result of slope stability analysis is an increase of safety factor by 1.729, which existing factor is 1.244. The countermeasures also involve drainage refinement and water flow diversion so that water will not penetrate to landslide zone.