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Total Building Collapse from a Single Column Failure

jaydeehess said:
That really only applies to the upper 40 storeys....

The towers were the same from ground to top except for the beams on mech floors.

The collapse of the towers was a failure of the tube in tube design. The collapse of WTC7 was the result of the failure below the part of the structure that was nominally a tube in tube design.
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The twins had the tridents below flr 7.... 1/3 the number of columns supported the facade... no vierendeel membrane down there. So the tube WAS supported from below 7 on tridents then the tridents and 3 on columns.

The entire structure of 7wtx below floor 8 was quite the Rube Goldberg puzzle of interconnect massive load transfer structures holding up the 40 stories above. Therefore it's pretty obvious that the Rube Goldberg structure came apart and the 40 stories INCLUDING columns lines 79,80 and 81 came down. Those 3 columns lines were taken down by TT1 and TT2 and which all caused the braced frame at the perimeter to fold in... THEN the curtain wall and the moment frame they were attached dropped....

This was completely different from how the twins came down.
 
Tony Szamboti said:
The bolts would shear before the seat was destroyed as the girder is sitting on it while it is expanding.

Additionally, there is a 2" thick x 14" deep x 18" wide support plate under the 12" wide x 1" thick bearing seat.

The girder can't fall with the stiffeners included.
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What if it sheared and walked the entire distance off of the seat? Is this not possible?
 
Tony Szamboti said:
WTC 7 ...
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I like your early work as readcddeal.
Tony Szamboti said:
... I also told you via e-mail that I watched Larry Silverstein use the actual words "Bldg. 7 was a controlled demolition for safety reasons" on a History Channel show called History's Business in late 2002, so I absolutely know I am right about that and none of yours or Popular mechanics non-engineering editors can say different.
... I am thinking of renaming you and your ilk "reskunkers" in lieu of "debunkers". ...
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Out right silly stuff.

reskunkers? Does this stand? Any luck with CD?
 
Tony,

Suppose Silverstein seeing his building burn and severely damaged from falling debris was wondering about what to do with what appeared to be an unusable and unsafe building... Obviously such a building would have to be taken down if the reports of frame warping and so forth were true (from FDNY). Why is it strange that the building owner would speak with his insurance company about his coverage for the loss? Would they replace the structure? Would they cover the cost of dismantling / demolition? Obviously the discussion was preliminary because there was no insurance appraisal of damage. That damage turned out to be so severe... and worsening until the building finally collapsed at 5:20.. after burning without any fire suppression for 8 hours or so.

To me this seems like a perfectly normal discussion for a building owner to have facing such an enormous loss. Maybe he had no idea that it would collapse? Maybe the reports of such severe damage were sufficient to decide in his mind that the building was no longer habitable or safe and had to be a write off. And once that was determined by FDNY when they withdrew their personal... which was assessing the structure... Silverstein was moving ahead to see what his options were. Perhaps it seems odd that he was already exploring his options on the afternoon of 9/11 and it was reported to be before the building collapsed. But it was pretty much finished a property which could be occupied... why wait?
 
Originally Posted by Tony Szamboti View Post
... I also told you via e-mail that I watched Larry Silverstein use the actual words "Bldg. 7 was a controlled demolition for safety reasons" on a History Channel show called History's Business in late 2002, so I absolutely know I am right about that and none of yours or Popular mechanics non-engineering editors can say different.
... I am thinking of renaming you and your ilk "reskunkers" in lieu of "debunkers". ...
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He didn't really say that did he? So flat-out lying?

Typical.
 
NoahFence said:
He didn't really say that did he? So flat-out lying?

Typical.
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I strongly suspect that context would play a big role in the "quote" he's claiming was made especially since we always see witness reports of "explosions" used without any regard for context as well. The only way to validate that anything remotely resembling what is claimed would have to be verified (which Tony seems unable to cite) and context has a tendency to never work in the CD crowd's favor.
 
Bumping for the tag team troofer pair......

NIST says "figure 10-19 shows that many of the floor beams in the southeast half of the floor reached temperatures around 600 C and remained hot for over and hour." (Pg 396 NIST NCSTAR 1-9)

However, when you actually look at Figure 10-19 9 (pg 412 NIST NCSTAR 1-9) , it clearly shows the beams nearest Col. 79 to be at the extreme end of the color scale (675 C)



"Temperature gradients through the depth of the steel beams and girders were affected by the presence of the floor slab. Temperatures were uniform (within 1C) across the bottom flange and web, but the top flange temperature was less by up to several hundred degrees, because the slab acted as a heat sink (see Figure 4-6 to Figure 4-8)" (pg 391 NIST NCSTAR 1-9)

"The beam elements could model a linear temperature gradient across the section, but a uniform temperature was determined to be a reasonable approximation for the temperature profile in the beam and girder sections." (pg 392 NIST NCSTAR 1-9)[/QUOTE]

"Connection damage was typically gradual, with bolts and/or welds failing sequentially over time."
(pg 490 NIST NCSTAR 1-9)

The temperature of the girder between Columns 76 and 79 on Floor 13 was sufficient to displace Column 76 to the west and Column 79to the east
(pg 527 NIST NCSTAR 1-9)
 
Animal said:
Bumping for the tag team troofer pair......

NIST says "figure 10-19 shows that many of the floor beams in the southeast half of the floor reached temperatures around 600 C and remained hot for over and hour." (Pg 396 NIST NCSTAR 1-9)

However, when you actually look at Figure 10-19 9 (pg 412 NIST NCSTAR 1-9) , it clearly shows the beams nearest Col. 79 to be at the extreme end of the color scale (675 C)



"Temperature gradients through the depth of the steel beams and girders were affected by the presence of the floor slab. Temperatures were uniform (within 1C) across the bottom flange and web, but the top flange temperature was less by up to several hundred degrees, because the slab acted as a heat sink (see Figure 4-6 to Figure 4-8)" (pg 391 NIST NCSTAR 1-9)

"The beam elements could model a linear temperature gradient across the section, but a uniform temperature was determined to be a reasonable approximation for the temperature profile in the beam and girder sections." (pg 392 NIST NCSTAR 1-9)

"Connection damage was typically gradual, with bolts and/or welds failing sequentially over time."
(pg 490 NIST NCSTAR 1-9)

The temperature of the girder between Columns 76 and 79 on Floor 13 was sufficient to displace Column 76 to the west and Column 79to the east
(pg 527 NIST NCSTAR 1-9)
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How far was column 79 displaced to the east?
 
Tony Szamboti said:
I guess it is hard to understand why you did not answer my question, so I will ask again.

How far was column 79 pushed to the east by the girder between columns 76 and 79?
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You are right.....you do not understand........it doesn't matter how far it moved.
But then, you will likely never get it. :rolleyes:
 
Tony Szamboti said:
I guess it is hard to understand why you did not answer my question, so I will ask again.

How far was column 79 pushed to the east by the girder between columns 76 and 79?
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Tony,

This entire discussion about column 79 and the girder framed into it is stupid. It's more than likely that the so called failure of column 79 was not at this floor though there likely was fire and so on which caused all sorts of problems there.

The evidence of movement of the building LEADING to the release seems to indicate the the initiation location was below floor 8 and below columns 79,80 and 81... ergo whatever happened on 13 was a RESULT of a previous failure and its "collapse" did not initiate the global release.

This is naval gazing in the extreme... about a model which was completely theoretical with made up inputs. And it appears that NIST got themselves in mess and you guys are all over them for it. Big deal.

Now look elsewhere for the explanation of the movements. Of course absent real time data it's all guesses and models. Some guess seem more reasonable than others. CD is the least likely so far.
 
To say that the girder between column 76 and 79 was restrained would be a massive understatement. Even discounting the support that column 79 had from elsewhere, to suppose that it was pushed to the east by this element gives the NIST hypothesis even more problems.
 

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