Experimental investigation of EPS geofoam seismic buffers using shaking table tests

The paper reports the results of six shaking table tests using reduced-scale model walls constructed with expanded polystyrene (EPS) panels to reduce dynamic earth loads due to base shaking. The results are compared with a nominal identical rigid (control) wall constructed without a seismic buffer. The test results show that dynamic load attenuation increased with decreasing geofoam stiffness. The test with the highest buffer stiffness resulted in a 15% reduction in dynamic load and the test with lowest stiffness resulted in a 40% reduction in dynamic load compared with the control wall. The results of these experiments provide proof of the concept that EPS panels placed against rigid walls can act as seismic buffers to attenuate dynamic loads due to ground shaking (e.g. earthquake). Additional quantitative data related to load–deformation–time response, back-calculated elastic modulus values for the EPS seismic buffer configurations, dynamic interface shear properties, acceleration amplification in the backfill soil and post-excitation stress relaxation-creep behaviour are also reported.