This article describes an analysis of the structural collapse that occurred in World Trade Center (WTC) building 5 due to fire exposure on 11 September 2001. It is hypothesized that the steel column-tree assembly failed during the heating phase of the fire. A failure analysis is performed to determine the response of the portion of the building frame that collapsed during the fire ignited by falling debris from the WTC towers. Results from a finite element, thermal-stress model confirm the column-tree failure hypothesis. Based on this model, the authors conclude that the catastrophic, progressive structural collapse occurred 2 hours into the fire exposure.
World Trade Center 5 Failure Analysis
February 27, 2008
Publication: Structure Magazine p 11-13
Services: Structural Investigation