STABILITY ANALYSIS OF HIGWALL SLOPE PT XYZ’S OPEN COAL MINING IN SOUTH KALIMANTAN

• Main Author: Wira Jati, Angkasa
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/61026
• Institution: Institut Teknologi Bandung

Mining activities are complex and full of high-risk activities which means all of safety aspects that supporting all activities in the mining sector must be considered, one of which is the stability of mine slopes. The problem of slope stability analysis will always be faced with the problem of uncertainty from the physical and mechanical properties of rocks. Simple slope stability analysis using the concept of the value of the factor of safety (FoS) is carried out by analyzing a single parameter of the material strength. The calculation of the probability of failure (PoF), therefore, is proposed to be carried out for accommodating the uncertainty of parameters in the physical and mechanical properties of the input material. PT XYZ has designed the LOM slope for the open pit coal pit T and the slope stability analysis will be carried out for assessing its stability. The method used for analyzing the stability of highwall slopes is the Bishop boundary equilibrium method. The input parameters of the material in the form of cohesion and internal friction angle are obtained from the results of laboratory tests. As for determining the PoF value, the existing data is then processed by descriptive statistical analysis to obtain the mean value, standard deviation, and also finding the data distribution type by applying the Kolmogorov-Smornov (KS) and Akaike Information Criterion (AIC) method. Furthermore, the slope model for slope stability analysis is created using software Rocsience Slide v6.0 which refer to the LOM design on the A-A' and B-B' sections. During the analysis, ground water condition is simulated by applying the hu values of 0.6, 0.8 and 1. The results of the slope stability analysis on the A-A' and B-B' sections for each design under various conditions are categorized in safe condition refering the Decree of the Minister of Energy and Mineral Resources 1827K/30/MEM/2018 in which the static FoS > 1.5; Dynamic FoS > 1.1; and PoF < 5%. Therefore, the highwall slope does not require a recommendation for improving the slope geometry.