Considerations of torsional effects on the seismic response of nuclear facilities: Fid-Bau Portal

Considerations of torsional effects on the seismic response of nuclear facilities

J. Xu / C. A. Miller

This paper studies the effects of torsion in models developed for performing soil-structure interaction analyses of nonsymmetric structure such as the process structures in many Department of Energy (DOE) facilities. Because of the unsymmetrical nature of these structures, the introduction of the torsional effects could significantly amplify their structural response to seismic motions. In this study, a typical nuclear process building was employed and seismic analyses were performed with the objectives of (a) generating a simplified stick model representation of the structure including and reflecting torsional effects; (b) introducing certain simplifications commonly employed in the industry to investigate the torsional effects on the seismic response of the structure and (c) comparing the results from the above models with a large scale detailed finite element analysis of the same structure. The study results of this paper indicated the pronounced effects of the consideration of torsion on the seismic response when nonsymmetric structures are modeled with simplified stick representations. With torsional effects considered, the study showed that the simple models indeed provide structural responses closely matching the detailed finite element solution but at much reduced cost.