Analisis stabilitas timbunan tanah menggunakan perkuatan geotekstil dengan software Geostudio

Abstract

Pemalang – Batang Toll Road project is located in Central Java Province. The soil conditions at the project site are highly diverse. Previosly the existing soil was a rice fields area which has a high potential for landslides and soil settlement due to the presence of embankment slopes. Therefore, a slope stability analysis is required for the embankment on the existing soil of the toll road. The stability analysis of the embankment slope is calculated using the limit equilibrium method using SLOPE/W Geostudio 2018 with varitions in embankment height at 6 meters, 8 meters, and 10 meters. Additionally, a manual calculation is conducted using the fellenius method for the 10 meter embankment. The embankment slope is considered safe if it meet the minimum requirements of the factor of safety (FoS≥1,5) without the seismic load, if affected with seismic load the minimum requirements of the factor of safety (FoS≥1,1). Embankment that did not meet the minimum requirements will be reinfornced using geotextile with an ultimate tensile strength of 55 kN/m. The analysis result for all of the variations without the seismic load have met the required factor of safety (FoS≥1,5). However the 8 meters and 10 meters variations with the seismic load have not met the minimum requirements of the factor of safety (FoS≥1,1), so it require reinforcement using geotextile. After reinforcement with geotextile, the factor of safety (FoS) values for the embankments with heights of 8 meters, and 10 meters are 1,267, and 1,638 respectively. These values meet the required factor os safety (FoS≥1,1). The total settlement that occurs directly on the 10 meter embankment slope is 2,201 cm, which is well within the allowable settlement limit of 131,667 cm.