SAFETY FACTOR ANALYSIS(SF) SAFETY FACTOR ANALYSIS (SF) OF SEDAYU MOUNTAINOUS AREA USING LIMIT EQUILIBRIUM METHOD 2D
SAFETY FACTOR ANALYSIS (SF) OF SEDAYU MOUNTAINOUS AREA USING LIMIT EQUILIBRIUM METHOD 2D
Landslides and floods that occur in Sedayu Village are disasters that often occur. Both disasters were strongly influenced by rainwater. The area of flow and distribution of surface water is poor resulting in flooding at the location which causes frequent landslides on the slopes. To express the stability value of a slope, a term is known as the value of the safety factor, which is the result of the comparison between the magnitude of the resisting force and the driving force of the avalanche. Slope stability analysis determines the safety factor of the landslide field. The safety factor value for safe soil or rock slopes is in the FK 1.25 – 1.5 according to SNI 8460 2017. This study aims to estimate the slope safety factor around the Mount Sedayu area using the 2-dimensional boundary equilibrium method. The boundary equilibrium method is a very popular method and is often used in slope stability analysis for translational and rotational slip types. The condition of slope stability in the boundary equilibrium method is expressed in the value of the factor of safety. Slope stability analysis is generally carried out using the 2-Dimensional Boundary Equilibrium Method because it is simpler. In the 2D slope stability analysis, the landslide that occurs is assumed to have an unlimited or continuous length. This method uses the principle of balance of forces. The concept of this method is to calculate the ratio between thrust and resistance forces based on the assumption of a potential landslide area and divide the slope into several slices. This method is useful for calculating the safety factor on slopes. From the results of a 2-dimensional slope stability analysis in the Sedayu Mountains area, the safety factor value is 0.91 and it can be concluded that the slope is considered unstable where the value of the FK factor of safety < 1. The smaller value a safety factor, slope is considered to be disturbed or unstable.