Application of Expanded Polystyrene (EPS) geofoam for pile-supported embankments over soft ground

The increasing demand for infrastructure, coupled with a global shortage of suitable land, has led to a rise in the construction of embankments over soft ground. A primary challenge in such projects is excessive settlement, which poses significant design and performance concerns. Pile-supported embankments have been widely adopted to address this issue; however, they exhibit notable settlements compared to unsupported embankments over soft ground. Consequently, there is a pressing need to explore methods that enhance the effectiveness and efficiency of these projects. One promising approach involves the use of Expanded Polystyrene (EPS) geofoam as a lightweight fill material, which reduces the overburden pressure on the improved ground and helps to minimise settlements in embankments. Given the lack of research on this combined solution, this study investigates the application of EPS geofoam in embankments to improve the performance of pile-supported systems using finite element modelling in ABAQUS/Standard. First, a numerical model was developed for a pile-supported embankment filled with conventional soil and validated using field measurements from a case study based on a project in France. Subsequently, the validated model was used to compare the performance of conventional soil embankments with that of EPS-filled embankments. The results demonstrate a 46% reduction in soil settlement and 36% reduction in pile stress at ground level when EPS geofoam is incorporated into pile-supported embankments compared to conventional soil fill. In conclusion, this study provides valuable insights into a technically sound and economically viable approach for embankment construction over soft ground.