Use of EPS for Roadway Embankments on Soft Soils-Paper

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The study evaluates expanded polystyrene (EPS) geofoam as a lightweight alternative to conventional soil in roadway embankments built over peat and soft clay. Researchers tested locally manufactured EPS blocks with a density of 35 kg/m³ under cyclic loads of 10–50 kN, measuring deformation and stress transfer. They then developed a Plaxis 2D numerical model, which reasonably reproduced the prototype’s behavior at strains of up to about 2%, and used it to compare soil and EPS embankments over soft ground.<br /><br />For embankments up to 10 m high, replacing soil with EPS reduced vertical stress in the underlying soil by about 39% and settlement by approximately 53%. The modeled consolidation time fell by roughly 45–51%, with the reduction depending on embankment height. EPS also limited stress increases as embankment height grew. Its lower weight and reduced lateral stress spread may allow narrower side slopes, potentially changing the typical slope from 3H:1V to 2H:1V, although this requires further investigation.<br /><br />The results suggest that EPS can reduce ground settlement and construction time on weak soils. However, the findings rely primarily on laboratory testing and two-dimensional numerical analysis; the authors note that further study is needed, particularly to assess slope design and its implications for construction cost.

Keywords

EPS geofoam

roadway embankments

soft clay

peat soil

lightweight fill

cyclic loading

Plaxis 2D

settlement reduction

vertical stress

consolidation time