<![CDATA[This study aims to analyze the stability of an open-pit coal mine slope at the Southern Pit, Block F, PT Garda Tujuh Buana Tbk, located in Bulungan Regency, North Kalimantan Province. The multi-bench mining system forms a 95 m high slope with an overall slope angle of 35°, consisting of soil, claystone, sandstone, siltstone, and coal layers. Slope stability analysis was conducted under static conditions using the Limit Equilibrium Method (LEM) through Slide2 software, applying the Morgenstern–Price and Spencer methods. The geotechnical input parameters were obtained from laboratory testing of 51 material samples. The analysis results showed deterministic Factors of Safety (FoS) of 1.239 using the Morgenstern–Price method and 1.241 using the Spencer method, with a very small difference of 0.002. Probabilistic analysis resulted in a Probability of Failure (PF) of 0.000% and a Reliability Index (RI) greater than 4.8 for both methods, indicating that the risk of slope failure under current static conditions is very low. The identified critical slip surface extends from the crest to the toe of the slope, indicating an overall slope failure mechanism. Based on the Decree of the Minister of Energy and Mineral Resources Number 1827 K/30/MEM/2018, the minimum FoS criterion for an overall slope is 1.30. Although the slope is currently considered stable because the FoS is greater than 1.0, the FoS values below the required safety criterion place the slope in the critical or marginally stable category. Slope management strategies are therefore recommended, including periodic FoS evaluation, regular geotechnical monitoring, groundwater level monitoring, and adjustment of slope geometry according to the design to prevent potential slope failures in the future.]]>
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