Numerical study of earth pressure reduction on rigid walls using EPS geofoam inclusions

This paper presents a numerical study performed to investigate the compressible inclusion function of Expanded Polystyrene (EPS) geofoam panels placed behind a non-yielding rigid wall. EPS geofoam panels placed behind a non-yielding wall can reduce lateral earth pressure acting on the wall by accommodating the lateral movement of the retained soil. Laboratory-scale physical testing was performed to evaluate various combinations of properties and dimensions of an EPS geofoam panel. A numerical model was developed to simulate the laboratory-scale tests. Model outputs were compared against test results to assess the reasonableness of the numerical predictions. A parametric study was performed using the numerical model to evaluate the effects of EPS geofoam panel material type and thickness on the non-yielding wall performance. The results of the parametric study quantify the magnitude of lateral earth pressure when the EPS geofoam panel is selected. Also, a systematic design approach for EPS geofoam panels as compressible inclusions against non-yielding walls is proposed based on the results of this parametric study.