Originally posted by gottago
You've presented a gross simplification, but if I follow your thinking correctly the 50/50 scenario you're talking about is your reasoning for the intiating of the collapse, as your last sentence attests.
However, I am not concerned here with the initiation of collapse, but why the collapse continued: what drove the collapse. The accepted theory is that the upper building mass crushed the tower below it.
My contention, backed by simply looking at the photographic and video evidence, is that there was not enough upper building mass falling upon the lower floors to destroy the towers down to the sub-lobbies.
Somehow this basic idea has become a discussion about the welding of the core column sections. If you look at a construction photo of the core, you will see it was a thoroughly braced structure, a web--the photos above posted by pilgrim and sublime show two large bracing plates for the horizontal beams on one side of the core sections. The vertical core column sections ends were staggered to reinforce their strength--all 47 did not have their welds at the same elevation point. The implications of bringing up the welds also implies enough horizontal forces acting in unison to create enough displacement to destroy the structure, when these forces during the collapse are entirely random.
The percentage of the falling structure that actually impacted the remaining core in the gravity-driven collapse scenario is simply missing, and I do not see how one can identify enough mass to justify the destruction of the lower portions of the towers.
[edit on 22-1-2008 by gottago]
Well, then you're reading waaaaay too much into my statement.
They swayed because they were designed to. The intact building performed as designed. It wasn't necessary to do 100% coverage and 100% depth welds to meet the design criteria.
The rest of your post is strawman and assertions based on untruthful statements and assumptions.
