Collapse mechanism analysis of the FIU pedestrian bridge based on the improved structural vulnerability theory (ISVT)

Abstract On Mar 152018, a pedestrian bridge on the campus of Florida International University (FIU bridge) collapsed during construction, and 6 victims were identified in this disaster event. This paper investigates the collapse mechanism of the FIU bridge through improved structural vulnerability theory (ISVT). A topological hierarchy model of the FIU bridge is established by the clustering process of the ISVT, and various possible collapse modes are identified by the unzipping process. Besides, the damage event that vibration effects by crane is considered in the computing work. By comparing the collapse mode identified by ISVT and the actual collapse scenario of the FIU bridge, it is found that ISVT could effectively identify the weakness and predicts the possible collapse modes of the FIU bridge by an quantitative vulnerability index. Then, parametric analyses are conducted for the bridge to different unforeseen damage events, and the collapse mechanism of the failure characteristics of the FIU bridge is also revealed by the ISVT. Finally, some suggestions are recommended for the structural design of rigid frame bridge like the FIU bridge.