The Effect of Variation of Stories’ Plan Size along Height of Relatively Tall Steel Buildings on their Seismic Behavior

In this study three groups of 12-story steel buildings with uniform, ascending and descending story plan size distribution (PSD) along their height, but having the same total architectural space, were investigated to find out how this distribution affects their seismic performance.

First, three site conditions of stiff, medium and soft were considered and all buildings were designed, by considering moment frames with concentrical bracings as their lateral load bearing systems. Then, for each site class, seven appropriate set of accelerograms were selected, and by using nonlinear time history analyses, the buildings’ seismic performance levels were compared based on the formation of plastic hinges (PHs).