SLOPE STABILITY ANALYSIS OF HIGHWALL AND LOWWALL OF OPEN PIT COAL MINE, PT XYZ IN SOUTH KALIMANTAN

• Main Author: PURWANTO - Nim: 12114054 , AGUS
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25142
• Institution: Institut Teknologi Bandung

<p align="justify">PT.XYZ is one of the coal mining companies intended to optimize the reserves in its Mining Business Licence Areas (WIUPs). This research was aimed to know the stability condition of overall slope geometry of the highwall and lowwall slope based on Life of Mine (LOM) design and to provide reccomendation design about the maximum overall slope geometry that the slope was geotechnically stable. Therefore, the most optimum overall slope geometry can be estimated to maximize the amount of mineable reserves on the WIUPs. <br /> <br /> The stability of geotechnical cross-section models 27 and 33 was analyzed by the Limit Equilibrium Method using SLIDE 6.0 software. The stability of the highwall slope was analyzed using the Bishop Method. While the stability of the lowwall, observed by each failure plane which is formed carbonaceous clay rock, was analyzed using the Janbu Method. <br /> <br /> Simulation and analysis results show that the overall slope of PT XYZ LOM design was unstable with Factor of Safety (FoS) value for Pit A & Pit C cross-section 27 and Pit A & Pit C cross-section 33 respectively 1.36 & 1.17 and 1.25 & 1.17. The overall slope of the lowwall was also unstable with the FoS value for cross-section 27 and 33 respectively 0.843 and 0.806. From these result, recommendation design was provided by changing the geometry of the slopes by reducing the height, reducing the slope gradient and changing the bench width. So, the new stability condition of highwall slope was obtained with FoS value for Pit A & Pit C crosssection 27 and Pit A & Pit C cross-section 33 respectively 1.85 & 1.47 and 1.52 & 1.54. While, the lowwall slope stability was obtained with FoS value for crosssection 27 and cross-section 33 respectively 1.402 and 1.293. Another alternative can be done to stabilize the slope by reducing the groundwater level (Hu = 0.5) and / or reducing the vibration effect (a = 0.03 g). So, in these condition, the stability of overall slope of the highwall was obtained with the FoS value for Pit A & Pit C cross section 27 and Pit A & Pit C cross section 33 respectively 1.51 & 1.31 and 1.39 & 1.3.<p align="justify">