Moderated Continuation - Why a one-way Crush down is not possible

MIKILLINI said:
Heiwa remains willfully ignorant. Floors 98-110 is the mass of 13 floors hitting the one (1) floor below. His willful ignorance is stuck on the 97 floors beneath instead of the one (1) floor, floor 97, that the mass of 13 is striking first.
I know I'm explaining it the same way as you are Fine, but Heiwa and his parrots are compromised if they acknowledge it.
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Mikillini, you know what thought really distresses me? It is remotely possible that Bill Smith can't grasp the simple--indeed, simplistic--point I'm making. But there is a school somewhere that gave Heiwa a degree in engineering. Should I be as shocked as I am? Is it even conceivable that he doesn't get the idea that the collapsing floors hit one floor at a time?
 
bill smith said:
Suppose a floor connection had been sheared at the perimeter column only and the concrete floor slabs had been pulverised would the remaining floor skeleton have hung off the core column connection ?
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No, the connections were not intended for cantilever loads, they were only intended for vertical shear.

You can see what they looked like in NIST NCSTAR 1-6B pages 23, 24,and 27 as well as in NCSTAR 1-1A.
 
(I isolated the vid from the quote Justin made)

failk.jpg


Aside from the fact that the model failed the moment he used chicken wire to model the exterior columns and left out the floor construction... it just got downright pathetic the longer I watched it... Why the hell did you make me watch that justin? :mad:
 
Heiwa said:
Part C gets decelarated and damaged in contact with part A. Happens every time and is the reason Why a one-way Crush down is not possible!
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.
Maybe if you say it:

Underlined ...
In Color ...
IN ALL CAPS ...
IN BOLD ...
IN BIGGER FONTS ...

... maybe you'll be less wrong.

Tom

PS.
NAHHHHH, just jerkin' your chain.
You're still just as wrong.
 
Grizzly Bear said:
(I isolated the vid from the quote Justin made)

[qimg]http://img338.imageshack.us/img338/2973/failk.jpg[/qimg]

Aside from the fact that the model failed the moment he used chicken wire to model the exterior columns and left out the floor construction... it just got downright pathetic the longer I watched it... Why the hell did you make me watch that justin? :mad:
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i literally pointed and laughed at the chicken wire
i nominated it for a stundie

ETA: did you watch part 2? lol
 
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funk de fino said:
Not until you act like an adult and admit you made false claims before. Then I will answer your questions.
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I don't think you can tell us whether the core is self supporting or not and back your claim that I am clueless when I say it was self-supporting. It's obvious you are using a silly little excuse to cover for it. Boy, you are really acting like an adult here Funky.
 
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Dave Rogers said:
You'll note, however, that the construction of the core has only proceeded to a couple or so storeys higher than that of the perimeter and floors, so this photograph is in no sense evidence that the core structure would be self-supporting if its unsupported part extended significantly higher than that.

Dave
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The fact that the core was self-supporting can be calculated. If you calculate it's moment of inertia you will find it is quite high about it's least radius of gyration and the critical buckling load is far above the maximum compressive load the columns could take. This means it would fail in compresive rupture as a unit before failing in buckling as a unit and thus was self-supporting.
 
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Tony Szamboti said:
I don't think you can tell us whether the core is self supporting or not and back your claim that I am clueless when I say it was self-supporting.
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The World Trade Center included many structural engineering innovations in skyscraper design and construction. The towers were designed as framed tube structures, with columns grouped around the perimeter and within the core. The perimeter columns supported virtually all lateral loads, such as wind loads, and shared the gravity loads with the core columns. All columns were founded on bedrock, which unlike Midtown Manhattan, where the bedrock is shallow, is at 65 feet below the surface.
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source


The perimeter columns were designed to provide support for virtually all lateral loads (such as wind loads) and to share the gravity loads with the core columns. Structural analysis of major portions of the World Trade Center were computed on an IBM 1620.

The perimeter structure was constructed with extensive use of prefabricated modular pieces, which consisted of three columns, three stories tall, connected by spandrel plates. The perimeter columns had a square cross section, 14 inches (36 cm) on a side, and were constructed of welded steel plate. The thickness of the plates and grade of structural steel varied over the height of the tower, ranging from 36,000 to 100,000 pounds per square inch (260 to 670 MPa). The strength of the steel and thickness of the steel plates decreased with height because they were required to support lesser amounts of building mass on higher floors. The tube-frame design required 40 percent less structural steel than conventional building designs. From the 7th floor to the ground level, and down to the foundation, the columns were spaced 10 feet (3 m) apart. All columns were placed on bedrock, which, unlike that in Midtown Manhattan, where the bedrock is shallow, is at 65–85 feet (20–26 m) below the surface.
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source

There's also the matter in which the core was provided additional lateral bracing at the base to compensate for the less dense exterior column spacing in the first few stories of the buildings height. The core was otherwise specifically designed to carry gravity loads while the perimeter column structure served to share these loads and provide the lateral support the building as a whole required.
 
Grizzly Bear said:
source


source

There's also the matter in which the core was provided additional lateral bracing at the base to compensate for the less dense exterior column spacing in the first few stories of the buildings height. The core was otherwise specifically designed to carry gravity loads while the perimeter column structure served to share these loads and provide the lateral support the building as a whole required.
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Are you trying to say the central core was not self-supporting because the exterior was used for taking the lateral loads from wind?

I am saying that it was self-supporting and did not require the floors outside of the core and the exterior column to brace it, so that it would not fall due to it's own weight. It could have stood on it's own with gravity loads being the only loading.

Do the calculations and you will see.
 
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grizzly bear said:
watched it... But i wore one twisted face because it just got dumber and dumber...
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I AGREE
 
Heiwa, you seem to enjoy invoking Newton's 3rd Law, so let's work with that.

When part C impacts the 96th floor, what effect does that have on the 1st floor? I would say essentially none. Therefore, the 1st floor has essentially no effect on part C.

Repeat for floors 2-95.
 
I'm sorry, I've just lost any remaining respect I had for Tony Szamboti, partly because he's unable or unwilling to discredit the pathetically wrong Heiwa axiom, but that he is actually adding to the stupidity of it:


Tony Szamboti wrote, regarding the Balzac Vitry demolition -
'If the lower block had been 9 times taller than the upper block it is extremely unlikely that a complete crush down would have occurred.'
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Tony, that is just so outrageously inane, it is an insult to anyone who considers themselves at least moderately intelligent and informed about basic engineering.

To paraphrase, Tony is claiming that (extrapolating this demolition to the 100 story level of WTC towers) the accelerating and increasing mass of material would have been stopped instead of destroying a WTC tower.

I'm not an engineer, but even I can see how bloody stupid Tony's statement is. It's an inexcusable apologetic claim for someone purporting to be a trained engineer. I'm disgusted.
 
Tony Szamboti said:
Are you trying to say the central core was not self-supporting because the exterior was used for taking the lateral loads from wind?
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The perimeter columns provided nearly all of the lateral stability to both towers, not just from wind loads. I made this pretty clear in my post and sourced it, how did you read it as only talking about the wind component?

Tony Szamboti said:
I am saying that it was self-supporting and did not require the floors outside of the core and the exterior column to brace it, so that it would not fall due to it's own weight. It could have stood on it's own with gravity loads being the only loading.
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Even if the core assembly were left for the entire height of the building without any additional lateral restraint as provided by the floor diaphragm and the perimeter columns? All of the case studies I've seen describe the core as being principally responsible for the gravity loads of the buildings. Not the lateral stability that would be necessary to resist wind loads and all other lateral loads that the building as a structural system would be faced with. Are there any studies that substantiate any impression that the core assembly would have been capable of supporting itself without the remainder of the structure present?
 
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alienentity said:
I'm sorry, I've just lost any remaining respect I had for Tony Szamboti, partly because he's unable or unwilling to discredit the pathetically wrong Heiwa axiom, but that he is actually adding to the stupidity of it:


Tony Szamboti wrote, regarding the Balzac Vitry demolition -

Tony, that is just so outrageously inane, it is an insult to anyone who considers themselves at least moderately intelligent and informed about basic engineering.

To paraphrase, Tony is claiming that (extrapolating this demolition to the 100 story level of WTC towers) the accelerating and increasing mass of material would have been stopped instead of destroying a WTC tower.

I'm not an engineer, but even I can see how bloody stupid Tony's statement is. It's an inexcusable apologetic claim for someone purporting to be a trained engineer. I'm disgusted.
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If there is anything inane here it is comments like these. Just open mouth and insert foot is all one can really say about these types of baseless and unsupported quasi ad-hominem comments.

You obviously are not in a position to judge anybody's engineering capability.
 
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Grizzly Bear said:
The perimeter columns provided nearly all of the lateral stability to both towers, not just from wind loads. I made this pretty clear in my post and sourced it, how did you read it as only talking about the wind component?


Even if the core assembly were left for the entire height of the building without any additional lateral restraint as provided by the floor diaphragm and the perimeter columns? All of the case studies I've seen describe the core as being principally responsible for the gravity loads of the buildings. Not the lateral stability that would be necessary to resist wind loads and all other lateral loads that the building as a structural system would be faced with.
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I did not say he core was intended to provide lateral stability to other parts of the building, although it was an integral part of the lateral restraining system for the perimeter.

I said the core was self-supporting. It coud have supported itself due to gravity with no additional lateral restraint and with plenty of reserve. I think it would have also withstood winds of 40 mph.
 
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