Gravel-rubber mixtures as geotechnical seismic isolation systems underneath structures: large-scale tests vs FEM modelling.

According to the sustainable growth, the need for low-cost seismic isolation systems has led to proposals of new projects. The use of granular soils mixed with granulated rubber derived from scrap tires as a layer underlying the foundations of structures represents a solution for the mitigation of seismic risk and the management of waste tires. Only a few small-scale experimental studies on this subject are available in the literature. The first experimental campaign on a full-scale prototype structure founded on gravel-rubber mixtures (GRMs) with different rubber content per weight was recently carried out in Thessaloniki (Greece). Ambient noise, free- and forced-vibration tests were performed. This paper shows a comparison between the results achieved during the forced-vibration tests and the results obtained by a non-linear 3D FEM modelling of these tests. This com-parison allowed us to investigate the isolation capacity of GRMs and the effects of the rub-ber content per weight