Abstract

Soft soil is a problem in construction because it has low bearing capacity and shear strength. This condition when used as a road subgrade results in the settlement of the embankment soil. An innovative and environmentally friendly method for soil improvement is the use of geofoam. Geofoam is a polystren with a density of 11.2 - 45.7 kg/m³, so it can be used as an alternative to lightweight fill. The purpose of the study was to determine the decrease in subgrade without geofoam and subgrade with geofoam EPS 22 using Plaxis 2D version 2023. The method used is a numerical method with the Palxis 2D version 2023 application. The load variations used are 0, 10, 20, 40, and 60 kN centralized load. The maximum settlement of the unreinforced soft soil was 45.102 mm at a load of 60 kN with a safety factor of 1.079. In the subgrade with geofoam of 6.656 mm at a load of 60 kN with a safety factor of 4.455. In conclusion, geofoam as embankment on soft soil subgrade can reduce soil settlement with a safe safety factor value for the decline in soil embankment.