Laboratory Studies on Scaled Physical Building Models Founded on Sand-Rubber Tire Shred Mixtures

The sand-rubber tire shred mixtures have gained research importance for their potential as geotechnical seismic base isolation materials as found from the laboratory element testing on them. This paper deals with studying the possible isolation effect of the optimum sand-rubber tire shred mixture block used as a foundation material for the scaled physical models. A series of impact hammer tests were conducted on a single bay, scaled steel framed structure representing typical low-rise buildings. The dynamic response of the structure is studied by enumerating the fundamental frequency and the damping effects as a consequence of the usage of this novel geomaterial in the foundations. The influence and the potential of the sand-rubber tire shred mixture are highlighted by investigating the response of the structures with different foundation base conditions with various floors and loading conditions. Different base conditions comprise the structures placed on control materials like pure sand and pure rubber tire shred blocks beneath the footing. It is found that using a sand-rubber tire shred mixture in the foundation significantly reduces the fundamental frequency of the structure (up to 30%) and increases the damping ratio. The present study supports the findings of past laboratory studies that the sand-rubber tire shred mixture with the 10% gravimetric rubber content can be used as an effective seismic isolation material.