Abstract
Settlement development on hilly morphology in North Samarinda District has encouraged slope utilization through cut and fill activities, and a landslide on 12 May 2025 in Lempake Sub-District underscored the necessity of slope stability studies in the area. This study analyzes the stability of two simple sandstone slopes, Slope A and Slope B, in the Bumi Alam Indah Housing Complex, using the Bishop Simplified method. Data were obtained through lithological description, slope geometry measurement, rock physical properties testing, and Schmidt Hammer testing, processed using the Hoek-Brown to Mohr-Coulomb failure criterion to determine the shear strength parameters, cohesion and friction angle. Analysis was conducted under dry and saturated conditions and evaluated against the applicable minimum factor of safety (FoS). Result show that Slope A obtained an FoS of 1.528 (dry) and 1.294 (saturated), while Slope B obtained and FoS of 2.957 (dry) and 2.513 (saturated). Slope A failed meet the minimum safety treshold under saturated conditions due to a higher degree of weathering, whereas Slope B remained stable under both conditions. Modifying the slope angle of Slope A from 70° to 55° increased the FoS to 1.882 (dry) and 1.611 (saturated). Both slopes are interpreted to have the potential for rotational failure.