SEISMIC ISOLATION BEARING

摘要

A seismic isolation bearing includes a lower assembly, an intermediate assembly, and an upper assembly. The intermediate assembly is mounted on the lower assembly for X-axis linear movement relative to the lower assembly, and sloped wedges acting between the lower and intermediate assemblies generate a gravitational restoring force biasing the intermediate assembly back toward a neutral X-axis position with respect to the lower assembly in the event of seismically induced displacement. The upper assembly is mounted on the intermediate assembly in a similar manner for orthogonal Y-axis linear movement. Cylindrical rollers, friction reducing shoes, or low-friction interfaces are used between wedge surface portions to allow a small wedge slope angle. A buffer spring and damper unit are preferably provided between the lower and intermediate assemblies and between the intermediate and upper assemblies. Sweeper plates connected to the rollers are disclosed to provide self-cleaning of the wedge surface portions. Sacrificial and/or resiliently-mounted protective caps and sealing strips house the bearing and help shield it from environmental debris.