STABILITY ANALYSIS OF SLOPE AROUND THE WATER WAY AT CILAKI 1B MHPP, GARUT REGENCY, WEST JAVA BY USING THE FINITE ELEMENT METHOD

• Main Author: Erwan Sakti, Endha
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/67694
• Institution: Institut Teknologi Bandung

Cilaki 1B MHPP (Micro Hydro Power Plant) is one of the power plant projects owned by PT Sinergi Solusi Utama (SSU) which is located on the Cilaki River, Cibengang Village, Garut, West Java. The water source for the Cilaki 1B MHPP is channelled through a water way or commonly known as a water-carrying channel with a length of about three kilometers from the upstream in the dam to the downstream in a power house. The transverse waterway is located exactly below the slope, so there is a possibility of landslides, the collapse that can cover the waterway and obstruct the operation of the Cilaki 1B MHPP. Slope stability analysis needs to be carried out to evaluate the condition of the slopes around the waterway so it can be ensured its safety and to know the next follow-up so the operation of the Cilaki 1B MHPP can still perform well. The slope stability analysis method used the finite element method with a shear strength reduction approach using Phase2 8.0 software. The collapse criteria used in this analysis is Mohr-Coulomb. The stability parameter in this study is a Safety Factor (SF) which is approximated by the value of the Strength Reduction Factor (SRF) and the Probability of Failure (PoF). Slope stability analysis was carried out at three locations around the water way Cilaki 1B MHPP with cross-sectional models A-A', B-B', and C-C'. The results of the slope stability analysis show that the three slopes are stable because they meet the minimum requirements based on the Ministerial Decree of The Energy and Mineral Resources No. 1827 K/30/MEM/2018 for overall slopes with high landslide severity, namely Static SF 1.3; Dynamic SF 1.1; and PoF 5%. The recommendations for slope management are monitoring of slope shift using a total station and repairing and/or constructing a surface water drainage system in the form of ditches around the slopes to maintain stable slope conditions.