Edinburgh Napier University

  A Geotechnical Seismic Isolation (GSI) system is proposed in this study based on the use of Rubber-Soil mixtures (RSm) to facilitate the benefits of dynamic soil-foundation structure interaction. The latter is possible due to the lower stiffness and greater capacity to dissipate energy of RSm. However, the research done on RSm has been limited to the element scale context. In this study, the dynamic response of a modified soil foundation has been investigated by adding soft zones comprising RSm. A 1g shaking table was used to apply a sequence of sinusoidal excitations to a soil-lumped mass system. The results have shown that the rubber addition results in a reduction of the amplification at frequencies higher than the system natural frequency. This change in the dynamic response is due to the shift in the natural frequency and the dampening of the peak output accelerations. This study shows thus that an alternative design consideration with bagged soft zones, adjacent to the soil foundation, can offset the incoming disturbances and hence could protect both new and existing constructions.