Quote:
Originally Posted by Vulcan
I'm not a CT but at first glance a building imploding because it suffered damage near the top doesn't make sense. It's like topping a tree causing it's base to be damaged and falling over. It doesn't happen.
The explanation I've heard is that the fire caused by the fuel was so intense it melted the columns all the way to the base but if this happened the heat should have been so bad that no one would have survived to escape. Anyone care to comment.
|
I'll comment...the explanation that you heard was very wrong. Either the person who told you that was misinformed, or you interpreted the explanation incorrectly.
I won't give details, but the jist of the collapse is this: fire heated steel, significantly reducing its strength...the steel did not melt, even at the heart of the jet fuel fire. The heated beams sagged under their own weight, stressing connections. Some of these failed, largely due to the fact that dozens of outer support columns were severed. In the end, a progressive collapse was triggered when one floor fell onto the one below, adding to the already stressed joints. Since the floors themselves were not designed to handle the weight of higher floors (only the columns & core were designed for this), they failed. As the floors continued to collapse, the outer steel columns were bent, stressed, and otherwise robbed of all of the horizontal support they required to remain standing vertically. The building fell. Thank you, and good night.
A tree is not a building. A mountain is not a building. A chicken wire & toothpick model is not a building. What happened happened. It's unfortunate that you were misinformed, but now that's been fixed.