Seismic Analysis of Geofoam Backfill Retaining Wall

Expanded polystyrene (EPS) geofoams are used widely in civil engineering projects as it has lightweight and low density. The present study is to analyze the lateral pressures in the retaining walls using EPS geofoam as an inclusion in the backfill. Retaining wall with the height of 6 m is designed and modeled using PLAXIS. Geofoam is included as backfill in various orientations such as upper-triangular pattern, lower triangular pattern, and the rectangular pattern. Optimum orientation with regard to low lateral pressures is found. Using PLAXIS 2D software, seismic analysis is performed in the present model. Bhuj earthquake data is used as the input parameter for examining the seismic behavior. The acceleration response at the top, the middle, and the bottom of the wall with respect to time is plotted, and the peak values are compared. From the study, it is observed that the geofoam reduces lateral thrust by about 50% in seismic condition.