An innovative isolation bearing for motion-sensitive equipment

Seismic isolation can protect delicate equipment housed in structures under earthquake attacks. One of the common approaches to isolate equipments is by using isolated secondary raised floors on which the equipments are mounted. This paper presents a new rolling-based seismic isolation bearing, referred to as roll-n-cage (RNC) isolator, for motion-sensitive equipment protection using the raised-floor approach. The RNC isolator is described, modeled and characterized. The effectiveness of the RNC isolator is numerically assessed considering the case of equipment housed in upper floors of a building, where the accelerations are amplified and the motion contains strong components at long periods. The numerical results reveal that the proposed RNC isolator device can attenuate seismic responses effectively under different ground motion excitations while exhibiting robust performance for a wide range of structure–equipment systems.