Three-dimensional seismic isolation bearing and its application in long span hangars

Based on the seismic response characteristics of space frame structures, a new type of seismic isolation bearing defined as a three-dimensional seismic isolation bearing (3DSIB) is developed in this paper. The bearing offers excellent properties such as multi-dimensional seismic isolation, reasonable rotation capability, good ability to resist lifting load, uncoupled stiffness in horizontal and vertical directions, etc. In the 3DSIB, the horizontal dimension is designed by combining the Teflon sliding device and helical spring, while the vertical dimension is developed by introducing disk springs or helical springs. The mathematical model of the 3DSIB was established and its performance with the critical parameters was tested on a shaking table. Furthermore, the 3DSIB was applied in a 120 m span hangar structure and simulated using SAP2000 software to evaluate its performance in practical structures. The performance of the structures with and without 3DSIB was compared. It is shown that the hangar structure with 3D bearings achieves a better performance. The axial force and acceleration response of the structures with 3DSIB are effectively reduced, while the displacement response of the bearing is within the predetermined range.