Total Building Collapse from a Single Column Failure

jaydeehess said:
It certainly reduces the number of trucks required at the site if concrete is poured elsewhere.
The specific prefab floor design may not have been used elsewhere but I certainly recall seeing prefab concrete floor sections yravelling through town on flatbeds many timrs in the past few decades.
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I believe they assembled sections of the joists / decking at grade and lifted them in place. Keeping more workers on the ground instead of 50 stories up is just good common sense. it is not feasible in most high rise construction simply because of the scale of the typical project.
 
jaydeehess said:
Then what is JSO all bunched up about?
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He's "finding evidence" that shows the engineering of the WTC was deficit in the same fashion that truthers "find evidence" confirming controlled demolition: everything, regardless of whether or not it is true or logic confirms his bias.
 
Animal said:
I believe they assembled sections of the joists / decking at grade and lifted them in place. Keeping more workers on the ground instead of 50 stories up is just good common sense. it is not feasible in most high rise construction simply because of the scale of the typical project.
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It's fewer crane picks as well, which speeds construction as well as making construction safer.
 
jaydeehess said:
...I certainly recall seeing prefab concrete floor sections travelling through town on flatbeds many times in the past few decades.
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Animal said:
I believe they assembled sections of the joists / decking at grade and lifted them in place. Keeping more workers on the ground instead of 50 stories up is just good common sense....
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Lets not lose track of why we are down this particular side track - with the OP long lost in the passing of time. :D

This is what sent us down this side track. Sander made these comments in support of one of his side track arguments:
JSanderO said:
The twin tower long span erector set assembly using inexpensive truss joists was sure economical... and absent moment connections came apart like a cheap...
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It beats me WTF "Moment connections" have to do with joints that failed in shear as a result of impact applied overwhelming vertical forces.

AND - equally if not more confused:
JSanderO said:
The floor assemblies were ...dropped on to 6 bearing seats each... ...[t]his is certainly not what a moment frame would involve.
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TRUE ...BUT.... since when were the floor joists intended to be moment frames.

Meanwhile the OP has been both clarified and answered OR rebutted and stands unsupported by Sander. Together with its collection of "a bet both ways" questions in the classic structure of "have you stopped beating your wife"

My answers to the OP briefly restated are:
1) It isn't;
2) Not by itself;
3) Ditto;
4) Yes. (watch the double negatives) AND Situation specific;
5) Questions unanswerable until clarified;
6) False premise (and hidden under two layers of fog.)
7) Couldn't. Sander hadn't framed the questions at the time.
 
Newtons Bit said:
He's "finding evidence" that shows the engineering of the WTC was deficit in the same fashion that truthers "find evidence" confirming controlled demolition: everything, regardless of whether or not it is true or logic confirms his bias.
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Sadly that is true. It is classic truther style "evade by diverging" argument.

Which BTW, whilst pointing fingers at engineering, is taking attention away from the two big failures - egress/escape provisions and redundancy in fire fighting systems. And specification of those requirements is not the engineering role.

;)
 
JSanderO said:
Yet all those that were hit by heavy plane parts seemed to have failed. And they were not that heavy at those elevations either. But the column to column connections were unrestrained.. a bit odd no?
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There was nothing wrong with them until said plane smashed into them.
WRONG
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I've talked to literally thousands of New Yorkers after 9/11. You're absolutely incorrect.
WRONG
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See above.
Only one of them. You seem to think engineers are immune to error.
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You seem to think the same of your own logic.
Why???? The floor system assemblies were a one off design, never used before (or since?)
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Prefab parts are very common. You see them on trucks and at job sites all the time. Everyone else handled this one a thousand times better than me.
:)
 
ozeco41 said:
[qimg]http://conleys.com.au/smilies/thumbup.gif[/qimg] Sadly that is true. It is classic truther style "evade by diverging" argument.

Which BTW, whilst pointing fingers at engineering, is taking attention away from the two big failures - egress/escape provisions and redundancy in fire fighting systems. And specification of those requirements is not the engineering role.

;)
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You mean like the same way truthers take attention away from intelligence failures that killed 3000 while endlessly screaming about how an empty building collapsed? ;)
 
Justin39640 said:
You mean like the same way truthers take attention away from intelligence failures that killed 3000 while endlessly screaming about how an empty building collapsed? ;)
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That is one example. Sander tends to talk around a topic rather than follow any posted sequence of logic. Same result tho' - it is hard to keep the discussion progressing if we need to deal with multiple side tracks.
 
JSanderO said:
Wrong.

It's only nonsense to those who may not have the sense to see the relevance. I cited examples of industrial engineering failures... Do you deny these happened?

I am not seeking to turn anything done in the past into a unlawful act after the fact. I never mentioned any violation or criminal or civil code. I don't think there was intent to do harm. Incompetence and misconduct may not involve intent. In fact the engineers who screw up, always think they are doing a stellar job!

I don't even want to get into the legal arena. I am seeking the proper explanation for the collapses which I don't think NIST got right and assign the appropriate share of the cause to the engineering, planning and approval decisions. Some here claim these designs performed better than could expected. I find that a stretch.
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A witch hunt, that's just what we need, a good old fashioned witch hunt.

You're looking at the event with post 911 eyes, the designers of the buildings had no such vision.
 
JSanderO said:
Can a single column failure lead to a total building collapse?
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Yes, duh. Should the ICC adopt provisions to design for column failures? No. Should buildings that need to be designed to resist blast (such as federal buildings) design for column failures? Yes.
 
JSanderO said:
Can a single column failure lead to a total building collapse?
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Already answered several times by me and others:

Yes it can

BUT:
1) It is scenario specific. Some buildings may, most won't collapse from a single column failure; AND
2) What causes that single column to fail?

(Specifically what scenario are you assuming and what causes that first column to fail in your assumed scenario?)

AND:
3) Column 79 did not lead or cause WTC7 collapse.
4) Column 79 was without doubt a central feature of the actual collapse mechanism.

WHILST:
5) The NIST initiation by "girder walkoff" hypothesis is prima facie sound;
6) Your transfer truss initiated hypothesis is also plausible - good enough to be worthy of consideration.

HOWEVER:
7) We will never know the details for the WTC7 9/11 collapse; PLUS
8) You haven't presented any sound reason why the community at large, its building industry and its regulators should expend further energy seeking knowledge of those details.
 
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ozeco41 said:
Already answered several times by me and others:

Yes it can

BUT:
1) It is scenario specific. Some buildings may, most won't collapse from a single column failure; AND
2) What causes that single column to fail?

(Specifically what scenario are you assuming and what causes that first column to fail in your assumed scenario?)

AND:
3) Column 79 did not lead or cause WTC7 collapse.
4) Column 79 was without doubt a central feature of the actual collapse mechanism.

WHILST:
5) The NIST initiation by "girder walkoff" hypothesis is prima facie sound;
6) Your transfer truss initiated hypothesis is also plausible - good enough to be worthy of consideration.

HOWEVER:
7) We will never know the details for the WTC7 9/11 collapse; PLUS
8) You haven't presented any sound reason why the community at large, its building industry and its regulators should expend further energy seeking knowledge of those details.
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iirc, there is no evidence of a proximate cause of a TT1 failure. JSO postulates diesel fuel fires but both FEMA and NIST could not support such a scenario given no evidence that such fires were ever underway.
OTOH fires on the 12th floor are known to have been in play.
 
jaydeehess said:
iirc, there is no evidence of a proximate cause of a TT1 failure. JSO postulates diesel fuel fires but both FEMA and NIST could not support such a scenario given no evidence that such fires were ever underway.
OTOH fires on the 12th floor are known to have been in play.
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Yes. I'm being somewhat generous to Sander's hypothesis. There is no proof for either of these hypotheses - or any other that may be dreamed up. If we were to compare probabilities there is quite a bit more going for the NIST one. However this thread is Sander's OP. Sander resists even acknowledging that the NIST hypothesis is plausible and my purpose has been to persuade Sander to recognise that the NIST one is plausible and that neither his nor NIST's is ultimately provable - as per the summary in my previous post. (And several previous versions of then same thing. I can be stubborn ;))

Remember also that, despite all the lengthy but falsely premised arguments form both sides, no one (at least on this forum) has falsified the NIST girder walk-off hypothesis.

:D
 
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