ABSTRACT
This study investigates the use of Expanded Polystyrene (EPS) geofoam as a lightweight fill material for embankment construction over soft subsoils. A case study from Cochin, Kerala, where a highway embankment was originally built using conventional borrow soil, is considered. The embankment rests on highly compressible clay layers, requiring extensive ground improvement in the original design. As an alternative, a redesigned section incorporating geofoam blocks was developed and analyzed using 2D finite element modeling. The comparative analysis evaluated total settlement and vertical stress distribution under staged construction and Class AA traffic loading. Results demonstrate that the geofoam embankment reduced total settlement by up to 95% post-construction and 81% under live loading, with minimal stress transmission to underlying layers. The study highlights geofoam’s potential to eliminate consolidation delay, reduce deformation, and mitigate subsoil disturbance, thereby offering a cost-effective and efficient alternative for embankments over weak ground conditions.
