Some Misunderstandings Related to WTC Collapse Analysis

[Tony Szamboti]

Jeffrey proposes the hat truss system distributes load into the vertical columns. My understanding is that the spandrals (sp?), the horizontal steel beams which tie the vertical columns into a kind of web surrounding the buildings, serve to distribute load in a very significant way. How would this load distribution system compare with that of the hat truss system?

The spandrels were on every story of the perimeter columns and there was a lot more steel there and the load is acting over a much shorter distance from perimeter column to perimeter column so the moment isn't nearly as high as it would be in trying to transfer core loads to the perimeter. Jeffrey is out to lunch on that one and shows his lack of understanding mechanics and stress analysis there. There is simply no chance the core gravity load could have been transferred to the perimeter through the hat truss.