Influence of isolation hysteresis on the seismic performance of isolated buildings

Abstract

Seismic isolation is one of the most used protective technologies for earthquake engineering. Many innovative devices have been researched and implemented. Selection of the different isolation devices is commonly based on engineering experience, where no detailed and systematic comparison has been provided. In this paper, the seismic performances of a three-story office building isolated using five different devices were evaluated. The isolation devices included the bilinear, flag-shaped I, flag-shaped II, crystallizing rubber (CR), and rigid-perfectly plastic (RPP) models. These isolation devices were designed to achieve an equivalent performance at the seismic shaking intensity of 2% probability of exceedance in 50 years. The evaluation was conducted using the state-of-the-art assessment procedure at 2%, 10%, and 50% probability of exceedance in 50 years (50/50, 10/50, and 2/50) hazard levels. The results indicated that all the isolators performed well by limiting the financial losses. At both the 50/50 and 10/50 shaking intensities, the building with CR isolators experienced no repair costs, while those with bilinear, flag-shaped I, flag-shaped II, and RPP isolators had minor repair costs contributed from the content performance groups. At the 2/50 shaking intensity, all isolators incurred minor damages in the content performance groups. The building with CR isolators had additional repair costs because of the interior drift sensitive nonstructural components, while the building with the RPP isolators had repair costs contributed from the interior drift and acceleration sensitive nonstructural components and the acceleration sensitive equipment at the roof. Copyright © 2014 John Wiley & Sons, Ltd.