Analisa Kestabilan Lereng Area High Wall di PT.X berdasarkan Faktor keamanan

Slope stability is a key concern in open-pit mining due to its impact on safety and operational efficiency. Mine X, located in Kalimantan Island, faces landslide risks on its high wall slopes. This study aims to model slope stability and determine safe and economical slope geometry. The analysis was performed using the Limit Equilibrium Method (Bishop Simplified), both analytically and numerically, through Slide 6.0 software by Rockscience Inc. Input data were obtained from five geotechnical investigation points provided by PT.X, including cohesion, internal friction angle, and saturated unit weight. Two lithologies were analyzed—claystone and sandstone—with slope height variations (5 m, 10 m, 15 m) and angles (26°, 45°, 51°, 59°), under dry and saturated conditions. Simulation results show that the factor of safety (SF) decreases with increasing slope height and angle, especially under saturated conditions. Sandstone demonstrates better stability than claystone. The recommended optimal slope geometry is 10 meters in height with a 59° angle, yielding a SF ≥ 1.25 and aligning with the PC-400 excavator's cutting capability. This study provides a technical reference for designing safe slopes that support mining productivity.