EPS Geofoam Pavement Foundations Overlaid by Geocell-Reinforced Soil under Static Loading: Large-Scale Tests and Numerical Modeling

Pavement foundations supported on expanded polystyrene (EPS) geofoam blocks are vulnerable to excessive deformation or even failure owing to truck passage during construction. To investigate this, a series of large-scale static plate load tests, accompanied by numerical analyses, were carried out to determine the effects of overlying soil thickness, EPS geofoam density, and the gap between EPS blocks. Furthermore, the effect of geocell reinforcement on the performance of such pavement systems was evaluated. Test results showed that as the soil thickness increased from 300 to 600 mm, the surface settlement of unreinforced pavement decreased by up to 65%. Low-density EPS geofoam can double or triple surface settlements or cause premature failure in a system. Additionally, reinforcing the overlying soil layer with geocell causes up to a 54% reduction in surface settlements. A series of verified numerical analyses demonstrated that as long as the pressure transferred to geofoam blocks remains below the compressive strength of EPS geofoam, the increase in pavement surface settlement is limited. Furthermore, increasing the gap between EPS geofoam blocks can increase the surface settlement of unreinforced pavements, while geocell reinforcement can help to moderate these settlements. The results of this study can be used to develop solutions to some of the limitations encountered during the construction of EPS geofoam embankments and under static loading conditions.