Seismic isolation is a well known, accepted method for improving building performance. However, it is difficult to achieve floor accelerations less than 0.3 g without allowing extremely large drifts. This study investigated the use of two isolation layers to address this issue. The system showed improved performance (smaller story drifts and floor accelerations) while maintaining the same peak roof drifts as in a comparable base isolated building.
This research was also presented at the 11th Canadian Conference of Earthquake Engineering.