Seismic performance of raised floor system by shake-table excitations

Abstract

Damage of expensive equipment installed in the raised floor system of high-tech fabs was often observed during past earthquakes in Taiwan. This resulted in a huge loss of manufacturing functions and properties for the high-tech industry. Therefore, there is an urgent need to understand the dynamic characteristics of the raised floor system for future seismic protection. This paper explores the seismic performance of a raised floor system under shake-table excitations. The raised floor used was a pedestal-stringer frame structure supporting the simulated equipment. This raised floor system was the typical system frequently used in semi-conductor fabs of Taiwan. The input motions for the shake-table tests were the waffle-slab floor accelerations of a typical semi-conductor fab to simulated ground motions. The ground motions were simulated according to the phase spectrum and the maximum potential earthquake of the site located at Hsin-Chu Science Park, Taiwan. The dynamic characteristics of the raised floor system were studied and discussed. This study also employed the finite element package to carry out numerical simulation on seismic responses of raised floor systems. Comparison with the experimental data showed that the proposed simulation model achieved excellent performance. Finally, the effectiveness of base isolation for reducing the acceleration of the system was also studied. Copyright © 2011 John Wiley & Sons, Ltd. Copyright © 2011 John Wiley & Sons, Ltd.