A numerical model for EPS geofoam seismic buffers

Based on an explicit time-marching finite difference approach, a multiple horizontal layer model is proposed to compute the compression-load-time response of EPS geofoam seismic buffers placed against rigid walls to attenuate earthquake-induced dynamic loads. The seismic buffer is modeled as a linear elastic material. The soil wedge is divided into a number of horizontal slices. The boundaries of each horizontal slice are connected by a series of stress-dependent linear springs. The distribution and magnitude of compressive displacement and load on the EPS geofoam buffer are computed numerically. A physical test carried out at the Royal Military College of Canada, is used to investigate the accuracy of the model. The numerical results and physical test results for displacement and load on EPS geofoam buffers are compared and analyzed. The model is shown to capture the trends observed in the physical reduced-scale model shaking table test up to a base excitation level of about 0.g. Quantitative predictions are shown to be in reasonable agreement with physical test results. The model provides a possible method to analyze and predict the force and deformation distribution of an EPS geofoam, seismic buffer placed against a rigid retaining wall.