Physical and numerical modeling of EPS geofoam buffers for seismic load reduction on rigid walls

The paper describes a series of experimental shaking table tests carried out at RMC to demonstrate that expanded polystyrene (EPS) geofoam materials can be used as seismic buffers to attenuate earthquake-induced dynamic forces developed against rigid retaining wall structures. Two different numerical modeling approaches are described that were used to predict the results of the physical experiments. The methods are based on: 1) a simple displacement block wedge approach, and; 2) a FLAC code. Both numerical approaches are shown to capture the peak dynamic-force time response of the seismic buffer wall models. The paper demonstrates both proof of concept and successful modeling approaches that can be used to predict load attenuation during earthquake using suitably selected EPS seismic buffers.