Total Building Collapse from a Single Column Failure

I do appreciate WHY jso is asking these questions and I do know/understand/accept that he is NOT a 911 truther.

OTOH I also accept that the hypothesis of girder failure which took out the floor it held and likely that the debris collapse of that floor caused subsequent damage to the girders/beams of floor sections below that.
The fires would have also heated much of the section of col 79 and this plus the removal of bracing for several floors led to col 79 buckling in the unbraced direction.
Failure of col 79 and subsequent 47 storey debris fall likely caused destruction of TT1 as part of the global collapse.

I also accept that it is possible that TT1 failure might cause a very similar collapse. However, while there was fire on floor 12 , there was no evidence of fire in the location of TT1. Thus, while TT1 might cause the same result, there is no obvious cause of TT1 failure.
 
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jaydeehess said:
I do appreciate WHY jso is asking these questions and I do know/understand/accept that he is NOT a 911 truther.

OTOH I also accept that the hypothesis of girder failure which took out the floor it held and likely that the debris collapse of that floor caused subsequent damage to the girders/beams of floor sections below that.
The fires would have also heated much of the section of col 79 and this plus the removal of bracing for several floors led to col 79 buckling in the unbraced direction.
Failure of col 79 and subsequent 47 storey debris fall likely caused destruction of TT1 as part of the global collapse.

I also accept that it is possible that TT1 failure might cause a very similar collapse. However, while there was fire on floor 12 , there was no evidence of fire in the location of TT1. Thus, while TT1 might cause the same result, there is no obvious cause of TT1 failure.
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Why does it matter? I'm not being snarky, I really want to know.
 
jaydeehess said:
I do appreciate WHY jso is asking these questions and I do know/understand/accept that he is NOT a 911 truther.
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Me too. In fact I hold Sander in high regard for his openness and honesty in putting his thinking openly in view. Consequently I have spent many thousands of words "discussing" with Sander on three forums. It is difficult because he has a distinctive vague/ambiguous/foggy style - disfocussed. He does not respond to anything that is posted which is tightly focussed, explicit and reasoned. Just look to his responses to me in this thread and see for yourself.

Back at post #58 of this thread I summarised where he is coming from. Two main points (1) He thinks transfer truss failure was the initiator of collapse and not girder walk off. And he insists that he is right and that NIST is wrong. He will not accept that both are plausible alternates. (2) He was advocating criminal sanctions against those persons who did the faulty design. He has backed off somewhat on that second point.

I have many times advised him that (a) his transfer truss failure is plausible; (b) that IMO the NIST girder walk off explanation is also plausible; (c) That it is extremely unlikely (AKA impossible) to get enough data to know with certainty what those details were AND (d) why does it matter PLUS to whom does it matter?

I suggest that is as good a summary of the situation as we will get. If anyone has a better one post it.

Sander accused me of not answering his questions. Reality is that I am probably the only person posting who has answered all the OP questions. Reality also seems to be that Sander doesn't like the answers. BUT he will not better them. I responded firmly to his challenge at post #159 - he got annoyed - didn't like the answers and again accused me of not answering his questions so I posted the proof at post #161

At that point I withdrew from participation....no point engaging in one sided discussions.

Nothing has changed. I may try once again to dig through the ambiguity of the recent posts but this bit of persistent untruthfulness has gone way beyond a joke:
JSanderO said:
Ozzie says, details don't matter all that much. I say they do if engineering/design turns out to be the key factor for total collapse.
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I don't say that. I never have. And I have called on Sander many times to stop posting the untruthful claim. It arises from my insistence that all relevant and significant details be included in any explanation. AND that irrelevant or insignificant ones are - would you believe - irrelevant and/or insignificant. :rolleyes:

Sander disagrees
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jaydeehess said:
short answer - building codes and avoiding it happening again
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With all due respect... that's a but of a dodge for the engineering aspects of these three towers.

As a general comment... these three designs have many very unusual engineering attributes to them. Why have not these come under some scrutiny? Why precipitate the recommendations to "improvements in codes"?

What sort of improvements? extend the hrs of fire protection rating?

Column 79 could be the location of the initiation as the EPH collapse was the first obvious movement that the tower was coming down. Structure under it had failed... We don't know how far down the failure... Could have been anywhere from the ground up to about flr 20 which is the visible portion of the facade where the EPH collapse can be observed.

I've asked for explanation how girder walk off fails the column. No one has explained that to me. When someone provides the explanation girder walk off will be on the table as a possible cause for the initiation.

It's true that there is no evidence to support first around the transfer truss region. But there are no reports either that these structures were fine.

My understanding is that Hess was trapped by the East stair and if so the explosion he witnessed was in the transfer truss region. What else it did besides blow up the stair is another matter. I don't buy the notion that falling WTC debris crashed into the East stair at flr 6 or so. That makes no sense at all. More plausible is that electrical power equipment exploded. And there was plenty of that down there.

I've suggested that the massive truss failure could gave occurred at the splices which were 3/4" bolts and plates... both more susceptible to heat damage than 5" thick plate of the trusses themselves. Ergo it would not take the raging fires for extended periods to fail the connection and a truss. Perhaps.

If you don't want to explore TTF then support girder walk off... not that it happened... but how does that progress to a building collapse.

Take your pick.
 
JSanderO said:
As a general comment... these three designs have many very unusual engineering attributes to them. Why have not these come under some scrutiny? Why precipitate the recommendations to "improvements in codes"?
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Because doing so improves the safety of future buildings and skips the witch hunt as to who to blame for something in the past (that was outside of what could be expected to happen).

The investigation was about moving forward not looking to blame someone for something no one really (reasonably) expected to happen.

You seem to want to point blame more than improve and learn. Why?
 
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ozeco41 said:
He wants to discuss it not just label it.

I missed where you were coming from - your question "Why does it matter?"

I answered "Why does it matter to Sander?"
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I missed that. It is a better question.
 
DGM said:
Because doing so improves the safety of future buildings and skips the witch hunt as to who to blame for something in the past (that was outside of what could be expected to happen).

The investigation was about moving forward not looking to blame someone for something no one really (reasonably) expected to happen.

You seem to want to point blame more than improve and learn. Why?
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I want to learn and am trying to figure it out.

But I am an accountability guy.

I think the people who designed and planned Fukushima should be held accountable... the engineers of Bhopal, the captain of the Exxon Valdez, the engineers who designed the BP Deep Water Horizon, those who caused the real estate / mortgage crash, the designers of the Pinto gas tank and numerous killer drugs and the list goes on... and it should include those who designed, planned, approved and executed the WTC, if it can be shown that they were incompetent or negligent in failing to protect the public.

If we refuse to understand what happened and wash it away by saying unfought fires... we are not learning and we are missing an accountability moment.

I believe that whether it was a girder walk off, or a connection of a field assembled transfer truss, or the decision to use light weight long span trusses... some accountability is in order.

Of course people blamed the event on hijackers and vengeance was sought and it was not a learning experience about how the US should conduct its foreign affairs.

And those who are not part of the solution are part of the problem.
 
As a structural engineer, and someone who believes engineers should be accountable, I believe that the engineers of WTC1, 2 and 7 should be given medals for creating outstanding structures. WTC1&2 each stood for about an hour, giving most of the people below the crash impact time to evacuate. WTC7 stood for hours and hours while engulfed in an unfought fire. Those are both fantastic examples of good design.

The big improvement that skyscrapers need to account for is egress. But that's an architectural issue.
 
JSanderO said:
Of course people blamed the event on hijackers
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You seem surprised by that. Should the hijackers have received posthumous commendations for pointing out possible faults in the design of the buildings?
 
JSanderO said:
But I am an accountability guy.
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OK, I got that. Tell me, where does accountability fit into what was reasonably expected to happen to a structure. These buildings did really well in my opinion. Building 7 lasted far longer than what would be required by code giving everyone time to get out.

What standard do you think these people should be held to? :confused:
 
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DGM said:
OK, I got that. Tell me, where does accountability fit into what was reasonably expected to happen to a structure. These buildings did really well in my opinion. Building 7 lasted far longer than what would be required by code giving everyone time to get out.

What standard do you think these people should be held to? :confused:
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Before 911 was the main concern of architects and engineers the possibility that a huge airplane would crash into the building that they were designing? If not then it was very remiss of them, it happens all the time. Is there such a thing as a quasi-truther and quasi-truther standards?
 
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Newtons Bit said:
As a structural engineer, and someone who believes engineers should be accountable, I believe that the engineers of WTC1, 2 and 7 should be given medals for creating outstanding structures. WTC1&2 each stood for about an hour, giving most of the people below the crash impact time to evacuate. WTC7 stood for hours and hours while engulfed in an unfought fire. Those are both fantastic examples of good design.

The big improvement that skyscrapers need to account for is egress. But that's an architectural issue.
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I don't disagree with improved egress regs. But I don't know that a skyscraper would come down right at the moment of a plane strike. Sever damage as we saw, perhaps shearing off a section.. slicing through kinda thing. But structures such as the twin towers did not last very long ... less than the standard 2 hr rating for fire protection and they totally collapsed.

Were was much innovation in the Skilling/Roberston design. Unfortunately that innovation which saved the developers money and made erection go very quickly (cost less too) led to the towers collapsing as quickly as they did... in a process which has been called ROOSD.

I would guess that the Empire State Building if hit as the twins were would not have collapsed totally if at all and surely not in the brief period of time that the twin towers did. I had an office on the 74th floor of the ESB and it was built like a battleship... very much unlike the erector set construction of the Twin Towers.

Those designs were so outstanding that no developer would do something similar (engineering design) like that every again. You can count on that.
 
Newtons Bit said:
As a structural engineer, and someone who believes engineers should be accountable, I believe that the engineers of WTC1, 2 and 7 should be given medals for creating outstanding structures. WTC1&2 each stood for about an hour, giving most of the people below the crash impact time to evacuate. WTC7 stood for hours and hours while engulfed in an unfought fire. Those are both fantastic examples of good design....
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The buildings were designed to the standards of the day:
1) "x" hours fire resistance to give time for;
2a) All the occupants to escape; AND
2b) Fire fighting efforts to be started.

AND
3) No expectation or allowance for attacks with aircraft, mini-nukes or laser beams from space.

AND
All three passed the test. WTC 7 met its design goals. The failings with the "Twins" were in lack of redundancy of:
a) The egress - escape provisions; AND
b) Fire fighting.
Both of those after the design parameters had been grossly exceeded. And the engineering survived - the architecture failed if we want to play those games - but I'm not about blame.

However the basis of the criticism of the engineering is that "the building failed at its weakest points" - and Sander arguing that NIST got the choice of "weakest point" wrong. Wow!!! Where else but the weakest point will a building start to fail?

And so what if NIST got it wrong? In structural cascade failures it is rare that we will know the exact weakest point or first point to fail. What matters to engineers designing future buildings is that it was a cascade. Their challenge is to build some level of cascade ("progression") resistance into their future buildings.
 
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