PROBABILITY OF SLOPE DESIGN FAILURE ANALYSIS OF OPEN PIT COAL MINE PT XYZ IN SOUTH KALIMANTAN PROVINCE

• Main Author: Manullang, Panangian
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/49953
• Institution: Institut Teknologi Bandung

PT XYZ is a coal mining company located in South Kalimantan Province intends to find geotechnically safe slope geometry recommendations so that it can optimize the amount of mined reserves owned by PT XYZ. In accordance with Ministry of Energy and Mineral Resources No. 1827K / 30 / MEM / 2018 / about mining technical management guidelines (Appendix II), slope stability analysis is done by calculating the value of the Safety Factor (FK) and calculating the Probability of Failure (POF) statically and dynamically. The POF calculation is preceded by the determination of the distribution function obtained through the processing of the goodness of fit test using the Kolmogorov-Smirnov method and the Akaike Information Criterion test for Cohession data, friction angle, and the unit weight of the slope compilers. From the results of processing the goodness of fit test will be obtained the best distribution that produces input parameters on the Monte-Carlo simulation method. Material characteristics are randomly generated 1000 times with Monte-Carlo simulation in Slide 6.0 software. The simulation results show that the three slopes with a pore pressure factor of 0.8 and a seismic loading factor of 0.05g are failure for all conditions. Slope with cross section 1 has a value of dynamic safety factor is 0.96 and the probability of failure is 98.7% . Slope with cross section 2 has a dynamic safety factor value of 1.02 and a probability of failure value of 36.8%, as well. Slope with cross section 2 has a dynamic safety factor value of 0.87 and a probability of failure value of 100%. Due to the fact that all slopes are in unsafe conditions, changes in the geometry of the slopes are carried out by reducing the height and overall slope angle with several experiments so that the best recommendations are obtained with FK and POF values when slope 1 dynamic conditions are 1.23 and 0%, dynamic FK and POF values of slope 2 are 1.20 and 0%, as well as dynamic FK and POF for slope 3 of 1.25 and 0%.