Lateral Pressure Reduction on Earth-Retaining Structures Using Geofoams: Correcting Some Misunderstandings

Block-molded expanded polystyrene and related geofoam materials can reduce lateral pressures acting on a wide variety of earth-retaining structures to almost zero under both gravity and seismic loading. There are two distinctly different functional ways to achieve this: lightweight fill and compressible inclusion. This paper updates the state of knowledge in this area with an emphasis on seismic buffers. This particular application, which makes use of the compressible-inclusion function, has seen increasing research interest in recent years. However there appear to be significant misunderstandings about material behavior that require clarification.