ASSESSMENT OF ROCK SLOPE STABILITY IN A HUMID TROPICAL REGION: CASE STUDY OF A COAL MINE IN SOUTH KALIMANTAN, INDONESIA

PT.X, a coal mining company in South Kalimantan, Indonesia, plans to use the highwall method excavate marginal reserves on final slope maintain production. However, stability of and determination dimensions are major concerns due unfavourable rock mass conditions caused by intensive weathering tectonics. This paper aims evaluate feasibility study area using empirical, analytical numerical methods. The innovation this research is integration these methods, which include classification, calculation load support strength, 2D 3D modelling, estimation recovered from design. initial condition assessment classification analytics geometry model determined mine openings pillar dimensions. Numerical modelling re-evaluated models obtain an optimal suggested thickness, opening, web pillars, barrier pillars 3.20, 3.00, 3.50, 4.00 m, respectively, with four one panel at Seam-C 2.50, m Seam-D. recovery for Seam-D estimated be 40.54%. Deformation was found have closest relationship safety factor most sensitive changes depth opening. provides reference future Indonesia other regions similar conditions.