13-08-2013, 11:40 PM
Jeffrey Orling Wrote:The service load on the perimeter columns constituted 20% of their capacity. I have done the calculations and it is also in the NIST report. See NIST NCSTAR 1-6 page lxxviii and Finding 51 and again on pages 240, 254, 321, and 337.Tony Szamboti Wrote:Lauren Johnson Wrote:Jeffrey's scenario in his cartoon has never been proposed by anyone who has published anything because it is fully impossible and a certain fiction, as the hat truss outriggers were not capable of transferring 12 stories of core load to the perimeter (the exterior columns that Jeffrey calls the façade).Jeffrey Orling Wrote:Basically you are getting the gist of the diagram. It's meant to show what happens as the core columns are weakened. When the lose capacity the 12 floors of the core ... and there were only 2 elevator chafts in the core at that height... were hanging from the hat truss. And this include part of the weight of the floors outside the core as the 24 perimeter core columns support about 45% of the outside the core floor loads. When the core lost capacity all of the loads were moved over to the facade columns which buckled and in so doing there was lateral translation and the facades slipped past each other 2 side passed outside and 2 inside. But surely the facade wasn't able to carry the floor loads alone including those inside the core up there. This mass.. became the ROOSD mass driving through the inside of the tower down to the ground.
This disagrees with the NIST analysis I take it--although the details escape me? And has this thesis been discussed in the requisite journals? I gotta say that anon posters over at randi don't cut it when it gets down to it. OK, now I will stare at the diagram some more.
The outriggers were A-frames meant to transfer antenna wind loads to the perimeter to gain a larger lever arm than just that provided by the core. They were about 10% of what would have been needed to transfer 12 stories of core load to the perimeter and would have failed in bending immediately when the core load was applied to them.
The truth is the outriggers did fail when the core load was applied to them and that is why the interior did go down first, as evidenced by the antenna drop before the exterior roofline, which had to wait for the core to pull the perimeter columns in at the 98th floor causing them to buckle and fail. It wasn't because they were overloaded from the top the way Jeffrey wants to say. That was impossible and it can be guaranteed that Jeffrey has no analysis showing the outriggers could take and transfer the core load he claims.
Additionally, the core load was not capable of overloading the perimeter even if it could be transferred by the outriggers. The perimeter columns only had 20% of their capacity used and they supported at least 50% of the building load. So if the core load was placed on them they would only be loaded to 40% of their capacity. Jeffrey's cartoon has no basis in reality and was certainly not the cause of failure for the perimeter. They did buckle but it was not due to overloading from the top as he claims. It was due to pull in creating extreme eccentricity (which columns cannot tolerate) by the failed and falling core.
According to Tony... FEMA proposed a similar explanation in their initial report. But of course this contradicts his conception and the absence of his recognizing the pre release building movements.
The service use of capacity was not 20% and that's purer fiction.
Why would you challenge something like that?

