Hubungan Klasifikasi RMR dan Faktor Keamanan Terhadap Penentuan Geometri Lereng Tambang Terbuka (Studi Kasus: Tambang Terbuka Batubara Desa Kebur, Kecamatan Merapi Barat, Kabupaten Lahat, Provinsi Sumatera Selatan)

tidak -1, -3 tidak memerlukan geometri lereng ABSTRACT Rock Mass Rating (RMR) classification is one of the classifications used in rock mass classification. The geometry of the rock mass on a slope needs to be considered in the analysis of slope stability. Slope geometry recommendations are needed to obtain a safe and stable slope safety factor in static, dynamic, and probability conditions according to KEPMEN 1827 K/30/MEM/2018. This research was conducted at the location of the open-pit coal mining Mining Business Permit (IUP) in Kebur Village, West Merapi District, Lahat Regency, South Sumatra Province. require a change in slope geometry, while PIT-1, PIT-5, and PIT-3 require a change in slope geometry. The better the rock mass class, the higher the safety factor value, so that the slope geometry does not require changes. The recommended slope geometry used is the original slope for PIT-2 and PIT-4, a slope with a geometric slope of 55⁰ for PIT-1, and a slope with a geometric slope of 50⁰ for PIT-3 and PIT-5.