Earthquake Load Attenuation Using EPS Geofoam Buffers in Rigid Wall Applications

The paper is a synthesis of previously published work by the authors that is focused on the use of expanded polystyrene (EPS) geofoam buffers for seismic load attenuation against rigid basement and soil retaining walls. The paper begins with a brief description of the first documented field application followed by a description of physical 1 m-high reduced-scale shaking table tests that provided the first "proof of concept". Next, details of the development and verification of a displacement-based model and a FLAC numerical model are described and simulation results that were verified against the physical shaking table tests presented. The numerical results include simulations using simple linear elastic constitutive models for the EPS buffers and granular soil backfill and more complex non-linear hysteretic models. Finally, the verified FLAC model was used to develop a series of preliminary design charts for the selection of a suitable seismic buffer based on characteristics of the design earthquake accelerogram. © 2013 Indian Geotechnical Society.