Perencanaan Dinding Penahan Tanah Tipe Kantilever Alternatif 1 Tinggi 4 Meter sebagai Penanggulangan Kelongsoran dengan Metode Analitis dan Program Plaxis 2D (Studi Kasus: Perkebunan Nusantara, Sumatera Utara)

Abstract

Landslides frequently occur in Indonesia due to various factors, including geological and topographical conditions, high rainfall, volcanic activity, and soil types prone to failure. Landslides can damage infrastructure and cause economic losses, as in the case at the palm oil mill owned by Perkebunan Nusantara. A slope failure on one side of the loading ramp disrupted the production process, requiring a geotechnical analysis to determine an appropriate reinforcement alternative so that the ramp could operate again.This study aims to analyze slope stability under existing conditions and after reinforcement. The analysis was conducted using two methods: manual calculation and numerical modeling with PLAXIS 2D 2024.2 software. The results from both methods were compared to evaluate the effectiveness of the planned reinforcement.Based on the analysis, the safety factor of the original slope was found to be below the required standard (SF < 1.5), indicating that the slope was vulnerable to landslides. After reinforcement with a cantilever retaining wall based on the proposed design, the safety factor increased to 1.506 under static conditions and 1.160 under seismic loading. Both values meet the stability criteria.Therefore, the cantilever retaining wall proved effective in improving slope stability and reducing landslide potential. This solution is expected to support smooth operations at the loading ramp and serve as an alternative method in slope reinforcement planning as well as a reference for landslide mitigation using retaining walls.