Simplified assessment of the seismic collapse capacity of flexible moment-resisting steel frame structures

Abstract

Sorting of the individual collapse capacities leads to the collapse fragility curve. It has been shown (Ibarra & Krawinkler 2005) that collapse fragility curves follow more or less a log-normal distribution. Thus, median, 16th and 84th percentiles of the individual collapse capacities are sufficient to approximate the collapse fragility curve according this distribution. In particular, simplified procedures provided for finding a fast and yet accurate estimate of the collapse capacity without performing IDAs rely on these statistically evaluated quantities. The proposed collapse capacity spectrum methodology belongs to this group of procedures.