Story strength demands of irregular frame buildings under strong earthquakes

Abstract

SUMMARYIrregular frame buildings with discontinuous columns in one or several stories have been vulnerable to collapses during strong earthquakes. This paper presents the investigation of the seismic response demands at irregular stories of such buildings in terms of story strength factor demand. In this study, a story strength factor was defined to represent the relative reserve strength against the formation of a story failure mechanism of the structure. In addition, a huge number of rigorous nonlinear inelastic dynamic time‐history analyses of various analytical models of 7‐story, 8‐story and 15‐story frame structures with discontinuous columns in one and two irregular stories were conducted under 29 strong earthquake records with various characteristics. The results show that the seismic response demands at irregular stories of the structures were well evaluated in terms of the story strength factor demand to avoid development of a story failure mechanism of the structures when subject to strong earthquakes. Copyright © 2011 John Wiley & Sons, Ltd.