I hope you didn't take
my post as an insult, Zhang, because I was being very sincere with that, and wasn't implying anything about your
intelligence in particular. There's just a lot of total bullcrap floating around that on first whiff sounds very believable.
Originally posted by zhangmaster
As far as I can tell though, everything else seems to make sense besides the "burning time" comparison of the WTC vs. other buildings as I mentioned
earlier. The author asks why the WTC collapsed after only an hour when other more structurally weak structures lasted 18 times that were left
standing. The glaringly obvious difference between the WTC and any other building the the fact that the WTC was hit by a plane.
The plane damage wasn't as much as you might think. Less than 15% of the perimeter columns were knocked out in either tower, and likely a similarly
minor (if not smaller) portion of core columns, since they were much thicker, spread out, and were only being assailed by already-broken-up plane
parts. I think one government report states that only about 2 core columns out of 47 or so could've been knocked out, and only then if the engines
made direct impact with columns, but I could be confusing this with another source.
Released NIST figures indicate that the structure would need about 75% column loss on any given floor, on average, for that floor to fail. So that
means the fires would've had to have caused an additional 60% column failure or an equivalent in loss of integrity. It's
extremely unlikely,
if not impossible, for that to have occurred, given the nature, length, and intensity of the fires within those buildings.