Geotechnical Assessment of Slope Stability in Laterite Nickel Mining Operations in Laeya District, South Konawe Regency

Abstract

The laterite nickel mining activities in Laeya District, South Konawe Regency, Southeast Sulawesi, are prone to landslides, requiring a stability analysis to ensure safety and production continuity. This study aims to analyze the physical and mechanical properties of slope materials, actual slope geometry, and determine the safety factor (SF) using the Bishop method with Slide software. The research methods include literature review, field observation, primary data collection (slope dimensions and soil samples), and secondary data from the company. Geometric data were processed using Global Mapper, ArcGIS, and Surpac, while physical-mechanical properties were obtained through laboratory tests. The results show that Sop soil has a density of 18.48 kN/m³, cohesion of 7.98 kPa, and internal friction angle of 22.42°; Limonite has a density of 19.30 kN/m³, cohesion of 12.32 kPa, and internal friction angle of 24.99°; while Saprolite has a density of 16.69 kN/m³, cohesion of 14.83 kPa, and internal friction angle of 26.47°. The actual slope geometry consists of three benches with a total height of 12.8 m and an overall angle of 33°. The Bishop method analysis using Slide V.6.0 software shows an overall SF of 1.802 with a landslide probability of 0.000%, indicating the slope is stable according to the ESDM Ministerial Decree No. 1827 K/30/MEM/2018, which requires a minimum SF of 1.3 for low-risk conditions. Thus, the slope at Pit Nursery is safe from landslide hazards, ensuring that mining activities can continue optimally and sustainably.