Slope Stability Analysis with Ground Anchor Reinforcement Alternative Based on Finite Element Method on the Blitar Southern Cross Road

Abstract

A slope stability analysis was conducted on a road section in Java to evaluate the effectiveness of using ground anchors as an alternative to soil nailing systems, based on the Finite Element Method (FEM). The modeling was performed by considering soil parameters obtained from laboratory tests, slope geometry, and loads consisting of traffic, pavement, and pseudo-static seismic loads. The seismic analysis used a Peak Ground Acceleration (PGA) value of 0.5g for the bedrock with an amplification factor of 1.2, which was then converted into a horizontal seismic coefficient (kh) of 0.3 for the slope stability analysis. The analysis results indicate that the existing condition with soil nailing is unstable, as evidenced by the occurrence of collapse and a maximum deformation of 0.026 m, which exceeds the allowable limit. The use of ground anchors improves the Safety factor (SF) to 1.11 (SF ≥ 1.1) and reduces deformation, thereby stabilizing the slope. Thus, based on the modeling results, ground anchors demonstrate superior performance in enhancing slope stability and reducing deformation caused by seismic loading.