2001-09-13 Why Did the World Trade Center Collapse

2001-09-13 \Zdenek P. Bazant\Yong Zhou Journal of Engineering Mechanics ASCE \9-11/official/papers\9-11 http://web.archive.org/web/20011031095744/http://www.tam.uiuc.edu/news/200109wtc/ Why Did the World Trade Center Collapse? – Simple Analysis Why Did the World Trade Center Collapse?  This paper presents a simplified approximate analysis of the overall collapse of the towers of World Trade Center in New York on September 11, 2001. The analysis shows that if prolonged heating caused the majority of columns of a single floor to lose their load carrying capacity, the whole tower was doomed. The structural resistance is found to be an order of magnitude less than necessary for survival, even though the most optimistic simplifying assumptions are introduced. Commentary:
 * reprint with skeptical commentary inserted in red text, and humorous asides in blue
 * Bazant and Zhou: Explaining the Collapses With Elastic Dynamic Analysis provides further analysis and debunking

&ldquo;The analysis shows that if prolonged heating caused the majority of columns of a single floor to lose their load carrying capacity, the whole tower was doomed. The structural resistance is found to be an order of magnitude less than necessary for survival, even though the most optimistic simplifying assumptions are introduced.&rdquo;   