Experimental Study on Seismic Performance of Equipment with Vibration Isolation Devices

Experimental Study on Seismic Performance of Equipment with Vibration Isolation Devices

The seismic performance of a building depends not only on the seismic capability of its structural components but also on the seismic capability of important equipment and nonstructural facilities inside the building. In order to maintain the desired functionality of a building during or after a major earthquake event, the important equipment and nonstructural facilities have to be always functional. In current practice, the important equipment, such as mechanical and electrical equipment, is usually mounted on the vibration isolation devices which are originally designed to prevent vertical vibration produced by the mounted equipment from transmitting to the building. However, these vibration isolation devices usually possess lower horizontal stiffness. If the natural frequencies of the building and the equipment with vibration isolation devices are too close during an earthquake event, there may have resonance that will cause severe displacement responses of vibration isolation devices and may even lead to serious collapse of the mounted equipment. For this reason, the dynamic hysteretic behavior and seismic capability of the commonly used vibration isolation devices were thoroughly investigated in this study through a series of shaking table tests.