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

SUMMARY 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.