24-08-2013, 03:28 AM
I did find another e-mail from a week earlier on Jan. 26, 2013 to your alter ego e-mail address JSanderO, so you should look there before calling anyone a liar. In it I do use some numbers and I had even sent you a sketch about it showing why the outriggers could not have transferred the core load to the perimeter. I also talk about the prying loads, which are even worse at the connection to the perimeter and would fail before the beam itself which is all I mentioned in my earlier post here.
Jeffrey,
If you noticed I also included a little sketch showing what the outrigger orientation would need to be to take the moments on them generated at the perimeter if they were to take the core gravity load.
I also did a calculation which shows the outriggers would have needed to use 17 foot deep 24 inch wide flange I-beams with heavy flanges and webs to just take these bending loads with no factor of safety.
However, it is the prying loads on the perimeter connections, which would ultimately govern the design. They would be very severe and would require each outrigger being fastened to an item which could take a lateral load of about 8 million lbs. for a 17 foot deep connection fastened at top and bottom. This would be 32 million lbs. per perimeter wall since there were four outriggers per wall. Of course, the lateral load requirement could be lowered if the depth was increased. For example, a 34 foot deep connection would need to be able to withstand a 4 million lb. lateral load, a 68 foot connection a 2 million lb. lateral load etc.. This tells you why 12 stories of core vertical loads could not be transmitted to the perimeter by the hat truss.
I used the moment involved of 1.8 billion in-lbs./outrigger and a yield stress of 36 ksi.
Tony
Of course, I didn't just start sending you information at two different e-mail addresses. You contacted me that way.
Jeffrey,
If you noticed I also included a little sketch showing what the outrigger orientation would need to be to take the moments on them generated at the perimeter if they were to take the core gravity load.
I also did a calculation which shows the outriggers would have needed to use 17 foot deep 24 inch wide flange I-beams with heavy flanges and webs to just take these bending loads with no factor of safety.
However, it is the prying loads on the perimeter connections, which would ultimately govern the design. They would be very severe and would require each outrigger being fastened to an item which could take a lateral load of about 8 million lbs. for a 17 foot deep connection fastened at top and bottom. This would be 32 million lbs. per perimeter wall since there were four outriggers per wall. Of course, the lateral load requirement could be lowered if the depth was increased. For example, a 34 foot deep connection would need to be able to withstand a 4 million lb. lateral load, a 68 foot connection a 2 million lb. lateral load etc.. This tells you why 12 stories of core vertical loads could not be transmitted to the perimeter by the hat truss.
I used the moment involved of 1.8 billion in-lbs./outrigger and a yield stress of 36 ksi.
Tony
Of course, I didn't just start sending you information at two different e-mail addresses. You contacted me that way.