Abstract

Soft soil characteristics have a low load bearing capacity causing construction settlement. Pavements and embankments have structural loads that must be considered by the subgrade as the bottom of the road layer. Soil reinforcement with lightweight construction materials such as foam mortar is considered as one of the alternative treatments to improve the engineering properties of soft soils and reduce construction loads. Foam mortar is a lightweight material consisting of a mixture of cement, foam, and sand with a density of 0.8 t/m3. The research with foam mortar reinforcement was conducted to analyze the amount of settlement and safety factor that occurs in order to improve the technical properties of the soil and reduce the weight of the embankment. Numerical analysis using Plaxis 2D 2023 with a centralized loading of 20 kN varies the model thickness of foam mortar reinforcement 0, 20, 30, and 40 cm. The results of the settlement analysis were 6.520 mm, 0.764 mm, 0.712 mm, and 0.690 mm with safety factors of 1.577, 4.136, 11.890, and 8.258. In conclusion, the maximum settlement occurred in the embankment without reinforcement while the highest safety factor was found in the 30 cm thick foam mortar. So foam mortar can be considered as an alternative material for soft soil subgrade embankment that can reduce the occurrence of settlement.