Perbandingan Alternatif Penanganan Tanah Pasca Longsor Pada Timbunan Jalan Tol

Abstract

The Tebing Tinggi-Indrapura toll road construction project at STA 103+350 is experiencing problems where the terrain at the construction site consists mostly of soft soil and it is also found that the area is a basin area which is the lowest point. The geotechnical problem that arises at the toll road site is the occurrence of landslides. Soft soil has a negative effect on highway construction because it causes settlement due the consolidation, which will make the pavement construction unstable and damage the pavement layer. Another problem associated with soft soils is their low bearing capacity. Consolidation is the gradual decrease in volume of a fully saturated soil that has poor permeability due to the escape of some pore water. This study examines how landslides are controlled at STA 103+350 on the Tebing Tinggi-Indrapura toll road with reinforcement where the reinoforcement used is using minipile reinforcement with additional LTP. The LTP used is geotextile and reinforced concrete slab (slab on pile). The method used is the finite element method in geotechnical software to obtain the Safety Factor (SF) value. Based on the analysis results from geotechnical software, the SF value during the operational period after reinforcement with alternative 1 (minipile without LTP), alternative 2 (minipile + LTP geotextile) and alternative 3 (minipile + LTP slab on pile) are SF = 1.7324; SF = 1.7353 and SF = 1.7432, respectively. Minipiles are very effective when placed in hard soil layers or over soft clay soils.