Slope stability analysis in The Babahrot-Blangkejeren road section sta. 13 + 885

Abstract

The Babahrot - Blangkejeren road section located in Aceh Barat Daya Regency is one of the roads in Aceh Province that often experience landslides because of its location, especially on the Singgah Mata Mountain track, which is in hilly areas. Landslides often occur at STA 13 + 885 at the foot of Singgah Mata Mount. Access to this lane is used for economic, educational, and social activities from Gayo Lues Regency to Blang Pidie, Aceh Barat Daya Regency. The impact of landslides is the disconnection of Gayo Lues community access to Southwest Aceh and vice versa. Therefore, it is necessary to do a slope reinforcement study at the top of the road construction. The analysis used to find the safety factor (FK) was Bishop Slicing Method. For comparison, the safety factor was also analyzed by using an application program (Plaxis). The results of the analysis of slope stability in the initial conditions using manual methods (Bishop Slicing Method) and using the application program (Plaxis) show that the average safety factor against landslides is smaller than 1. Thus, it can be said that, in the existing conditions, the slope is unstable. So, it is necessary to do slope reinforcement to prevent landslides. Based on the results obtained after the improvements to the slope angle and the use of reinforcement slopes with cantilever retaining walls, the value of the safety factor for landslides increased from 0.810 to 1.620.