DETERMINING LOWWALL AND HIGHWALL SLOPE GEOMETRY IN COAL MINE PT XYZ

• Main Author: Rahmat Shaleh, Arif
• Format: Final Project
• Language: Indonesia
• Subjects: Pertambangan dan operasi berkaitan
• Online Access: https://digilib.itb.ac.id/gdl/view/49315
• Institution: Institut Teknologi Bandung

PT XYZ is a coal mining company that try to optimize the coal reserve in his mining business license area (WIUP) by determining the optimum. Ultimate Pit Limit (UPL). The determination of the UPL is very dependent on slope stability recommendations. In Indonesia, regulation regarding slope stability is stated in the Minister of Energy and Mineral Resources Decree No. 1827 K/30/MEM/2018. In the Minister Decree for overall slopes when Consequences of Failure is high, it must have a dynamic Safety Factor (FoS) 1.1 and static FoS 1.5 and Probability of Failure (PoF) value is 5%. This study is aimed to provide recommendations for the best and safe slope design in accordance with existing regulation and find PoF of the slopes. To get the PoF value, Slide 6.0 software is used to process it. It is necessary to know the type of data distribution function with the goodness of fit test. In this test, the Kolmogorov-Smirnov Test and the Akaike Information Criterion Test were performed on cohesion, internal friction angle and unit weight of the materials. The simulation results show that all the initial designs of PT XYZ are unsafe and have a PoF value of 100%. To get the slope in a safe condition, a redesign of the slope was carried out by reducing slope angle and lowering the groundwater level. Design recommendation result on section 1 at dynamic condition FS highwall 1.24, lowwall 1.21, then for static condition FS highwall 1.50, lowwall 1.51. Section 2 at dynamic conditions FS highwall 1.50, lowwall 1.27, then for static conditions the FS highwall 1.88, lowwall 1.58. For section 3 at dynamic condition FS highwall 1.24, lowwall 1.34, then for static conditions, FS highwall 1.50, lowwall 1.70, redesign gives a PoF value of 0% for all section.