SLOPE STABILITY ANALYSIS ON THE DUMP SLOPE DESIGN OF COAL MINE AT PT XYZ IN CENTRAL KALIMANTAN PROVINCE USING FINITE ELEMENT METHOD

• Main Author: Helfindo Rioardiansa, Asriya
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40247
• Institution: Institut Teknologi Bandung

PT XYZ is a coal mining company with high calories (high rank coal) in Central Kalimantan Province which planning to dump reject material from Coal Processing Plant (CPP) at two places that named North Dump and South Dump. The dump place design has been made. The material that will be dumped consist of three types broken material which is mudstone with certain specification based on size of fragmen and the percentage of broken material. Therefore laboratory tests are needed to determine the characteristics of broken material using Barton and Kjaernsli criteria. The laboratory test are then used to analyze slope stability from the dump slope design that has been made. The slope stability analysis is based on Mohr-Coulomb shear strength criteria with finite element method using Phase2 8.0 software. Parameter of rock shear strength based on Mohr-Coulomb criteria were obtained from conversion of Barton and Kjaernsli shear strength result from laboratory test using RocData 4.0 software. In the finite element method, the slope factor of safety is calculated using a Strength Reduction Factor (SRF) approach where the shear strength parameter is reduced gradually, so that all elements in the slope fail. Slopes with SRF greater than or equal to 1.0 are considered safe and if it is less than 1.0 it is considered unsafe. Based on laboratory tests and modeling of 24 slope models showed that the higher the percentage of large fragment in broken material, the value of the equivalent roughness (R) will be higher, therefore it will produce a high SRF value, and vice versa. Beside of that the modeling results show that all slope models have SRF values greater than 1.0, so that they can be stated safe. Therefore it is recommended to optimize the design of the slope by increasing the height of the slope and enlarging the overall slope angle so that the SRF value of the slope is greater or equal to 1.0.