reply to post by openyourmind1262
I have kept my opinion out of the subject of the building collapse because I think the technical discussion is ludicrous.
I watched the entire incident uncut on a C band satellite feed. I seen the video before it got to the news station. I seen everything. I did not see a
single thing that was out of place, or did not make sense to me.
But if you want my full technical opinion.
Here it is.
Caution, this will be long.
Building construction is primary exoskeleton with central supporting column.
Without the outside columns running up the outside, the building will not stand. The outside columns depend on the honeycomb of floors to keep those
The straightness of the structural columns is of central importance. If a structural beam is bent, or deformed, it loses almost all of it’s
compressive rigidity. It’s ability to support a weight while standing on end. Those floors are tied to the vertical beams to keep them from shifting
out of vertical and losing their ability to support weight.
Condition after impact. One one side, the columns were severed. All the weight that side was supporting was shifted to the extreme edge of the
adjacent sides. The floors on that side of the building was also destroyed. Thus the support that keeps the columns on that side of the building
straight is gone. The amount that the outside columns were bulged out buy the impact forces, is unknown. But you know it would have affected the
trueness of them to some degree. Thus, the columns that were saddled with the extra weigh were the ones that lost structural reinforcement from the
How close it was to instant collapse right after impact can not be known, but it was probably pretty freaking close. They were just standing by a
thread so to speak.
The question of how hot the fire got is absurd. Steel does not stay at an exact strength until it hits some magical temperature. The strength, and
brittleness of steel is continuously variable depending on it’s temperature. When the temperature of steel increases by 50 degrees, it will lose
strength. It doesn’t mater if it is from 50F to 100F, or from 600F to 650F it will still lose a measurable amount of strength.
The statement I keep hearing about having to get above 600C to lose an appreciable amount of strength is absurd. The definition of appreciable is in
refrence to a normaly designed complete structure with reserve strength. You have to get up to 600C to get to a point where you compromise the
strength beyond the reserve normaly built into structures.
The towers after the impact was not a complete structure with any reserve strength left to be found.
With the fires burning in the building, and the temperature increasing, the strength of the remaining structural support is going down. It will
continue to go down, until you reach a critical point.
When the first of the columns start to shift from true under the weight. Once that happens, then everything goes down. One side doesn’t buckle and
the top tip over. Once there is any displacement from true vertical, the columns that jump that gap between the two non aligned pieces will lose true
vertical weight and will buckle instantly. As the top shifts to the side just the slightest, it will put the columns on the opposite side into a kink.
It may be the slightest half degree bend or so, but once the column loses true vertical weight, it becomes spaghetti.
So, once the top shifts even the slightest, all the columns that jump that gap are going to buckle at once. That caused it to lose support on all
sides almost at once which end any tipping action that may push it to the side. All it’s left then, is gravity.
Once the mass above the break starts moving down, there is nothing, outside of god, that is going to stop it.
The floors in between are no where near the strength of the columns, so once the top starts moving down, the columns from below will go through the
upper floors like a hot knife through butter. Same with the upper columns going through the floors below the break.
Once the mass starts moving down, it starts clearing the floors below it, which makes the mass bigger, which aids in the continued collapse. It
becomes a big blunt mass flattening what is below it. As the mass hits the next floor, it buckles it, and continues to push the outside columns out
and buckling them as it goes down. Straight down.
edit on 1-2-2013 by Mr Tranny because: (no reason given)