Seismic Response of Irregular Industrial Steel Buildings

Abstract

The suitability of the current Canadian procedures for seismic design of irregular industrial buildings is studied through the example of a titanium refinery located near Montreal, Canada. The building is braced by low-ductility concentrically braced steel frames and characterized by an irregular geometry, as well as an irregular mass and stiffness distributions. Three-dimensional elastic dynamic time history analyses were carried out for selected acceleration records compatible with the design spectra at the site. The results are compared to those obtained from the equivalent static force procedure and the response spectrum analysis method to evaluate how well these methods can predict deformations and forces in such highly irregular building. The study shows that the equivalent static method can adequately predict the displacements but may underestimate column and brace axial forces. In general, response spectrum analysis method provides appropriate estimates of the seismic response parameters given that a sufficient number of modes is considered in the analysis.