Sloped multi-roller isolation devices for seismic protection of equipment and facilities



The rolling motion of mutually orthogonal rollers respectively sandwiched between two bearing plates in which one or both have V-shaped sloping surfaces makes the sloped rolling-type isolation device have an excellent in-plane seismic isolation performance. In this study, the sloped rolling type isolation device in which a single roller moves between two V-shaped sloping surfaces along each principle horizontal direction is refined by incorporating multi-roller, built-in damping, and pounding prevention mechanisms. The associated dynamic behavior is further clarified, and a simplified twin-flag hysteretic model, which can be easily applied in most commercial computational tools is then proposed. Seismic simulation tests on the refined isolation devices (i.e. the sloped multi-roller isolation devices) with different design parameters such as sloping angles of bearing plates and built-in damping capabilities, together with a raised floor system by employing the sloped multi-roller isolation devices, were conducted. Not only is the efficiency of the sloped multi-roller isolation devices in seismically protecting the important objects, but also the practicability and accuracy of the proposed simplified numerical model in predicting the seismic responses of the sloped multi-roller isolation devices is experimentally verified. Copyright © 2014 John Wiley & Sons, Ltd.