Engineering Disasters:World Trade Center Collapse

Tom Rebold

Some Recent Engineering Disasters

Cosco Busan 50,000 gal oil New Orleans Levy Breach 700 deaths

Minneapolis Bridge 13 deaths Mars Polar Lander $120 million Any others?

Why do we have disasters?

Progress and Failure

http://www.usnews.com/usnews/news/terror/slides/wtc/index.htm

http://enr.construction.com/news/buildings/archives/040628-1.asp

NIST Report The study has determined, based on

photographs, that perimeter columns bowed inward on One WTC’s south face and Two WTC’s east face, “some” minutes prior to collapse. “Initiation of global collapse was first observed by the tilting of building sections above the impact regions” of both towers, says the report. One WTC tilted to the south and Two WTC tilted to the east and south and twisted in a counterclockwise motion.

WTC Steel Truss Burn Experiment

http://wtc.nist.gov/ http://wtc.nist.gov/media/gallery2.htm