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

aggle-rithm said:
Really! So tube-in-tube construction is really unnecessary? All it takes is a central core and concrete floors hanging off of it?

You need to get this astonishing discovery into print as soon as possible! Engineers will be kicking themselves for over-engineering everything so needlessly!
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Don't get too excited. I didn't say what you are implying here.

The perimeter was not self-supporting and needed the lateral support of the floors.

The floors were also not capable of being cantilevered off of the core either.

Are you an engineer? You don't sound like one.
 
Tony Szamboti said:
Don't get too excited. I didn't say what you are implying here.

The perimeter was not self-supporting and needed the lateral support of the floors.

The floors were also not capable of being cantilevered off of the core either.

Are you an engineer? You don't sound like one.
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'' The floors were also not capable of being cantilevered off of the core either.''

What do you mean by this Tony ?
 
bill smith said:
'' The floors were also not capable of being cantilevered off of the core either.''

What do you mean by this Tony ?
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Bill, the floors outside of the core needed to be supported at both ends. They were not intended for cantilevering, with support at one end only. The truss to column connections would have to have been designed for this, to resist cantilever moments, and they weren't. They were very strong vertical shear connections but were not intended to resist moments. The moments were taken out with support at the other side of the floor with a connection to the perimeter columns.

However, the complete central core itself was fully braced within itself and had a very high moment of inertia (or resistance to bending) due to it's 137 ft. x 87 ft. plan, which would allow it to be self-suporting over the height of the towers. It did not need lateral support from the floors and perimeter.
 
Heiwa said:
Say energy applied by part C with mass m dropping height h with acceleration g on part A is X.

Say energy required to deform parts C and A elastically before any failure is Y.

If X<Y part C bounces! Agree? No damages!

Let's assume X>Y. Thus energy (X-Y) = Z is available to cause local failures.

I suggest you need 10 Z to completely destroy the structure of one floor of parts A and C.

In this case Z will thus just produce local failures that damage 1/10th of one floor of parts C and A together.


Your car example is really stupid. A structure C(ar) which is 10 times heavier and 100 times more solid than part A is dropped on A. Evidently part C crushes part A.

On the other hand, if little part A is dropped on big part C, A gets damaged.
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Say you know no numbers. You just destroyed your Axiom.
 
Tony Szamboti said:
And why would it continue to move?
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Gravity. Gets you every time and will get us all in the end. Every building ever built fights it constantly. Do you not get this? What is it about falling that you find mysterious?
 
Tony Szamboti said:
Bill, the floors outside of the core needed to be supported at both ends. They were not intended for cantilevering, with support at one end only. The truss to column connections would have to have been designed for this, to resist cantilever moments, and they weren't. They were very strong vertical shear connections but were not intended to resist moments. The moments were taken out with support at the other side of the floor with a connection to the perimeter columns.

However, the complete central core itself was fully braced within itself and had a very high moment of inertia (or resistance to bending) due to it's 137 ft. x 87 ft. plan, which would allow it to be self-suporting over the height of the towers. It did not need lateral support from the floors and perimeter.
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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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Tony Szamboti said:
Funky, this is your chance to show you actually know something. If you don't believe it was then please tell us why you think the complete central core was not self-supporting.

Let's see if you actually have a clue.
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Not until you act like an adult and admit you made false claims before. Then I will answer your questions.
 
Tony Szamboti said:
Don't get too excited. I didn't say what you are implying here.

The perimeter was not self-supporting and needed the lateral support of the floors.

The floors were also not capable of being cantilevered off of the core either.

Are you an engineer? You don't sound like one.
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No, I'm not. But I do know when someone is making an irrelevant argument.

I asked you to enlighten us as to how the rubble from Heiwa's section A can be left out of the equation once it begins to move. You responded by saying that the core columns can stand on their own.

My response to that was to point out the folly of considering the core columns to be an automonous construction rather than part of a system. You, as an engineer, surely understand that the whole system is required to keep the building standing, even in the absence of thousands of tons of debris raining down upon it.

If I'm wrong, tell me how.
 
Tony Szamboti said:
The complete central core was self-supporting.
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Really?

So when the engineers designed the towers and did their calculations, they designed the central core to be self supporting? They all sat around and said "Let's make sure that the core, comprised of 47 columns situated in an 87' x 137' rectangle and being 1300' tall, will be self supporting." I suppose you have these calculations handy or the quotes that state this as being so.

I'm really curious now. How do you know this? Did you do the calculations yourself and figure this out or do you have quotes from the actual design engineers saying this?

Also, did you ever find the quote from Skilling saying that he and his people did analysis concerning the effects of fire on the structural steel core? I see that when ai asked this of you many times, you never answered. This seems to be the way you operate around here.
 
Gamolon said:
Really?

So when the engineers designed the towers and did their calculations, they designed the central core to be self supporting? They all sat around and said "Let's make sure that the core, comprised of 47 columns situated in an 87' x 137' rectangle and being 1300' tall, will be self supporting." I suppose you have these calculations handy or the quotes that state this as being so.

I'm really curious now. How do you know this? Did you do the calculations yourself and figure this out or do you have quotes from the actual design engineers saying this?

Also, did you ever find the quote from Skilling saying that he and his people did analysis concerning the effects of fire on the structural steel core? I see that when ai asked this of you many times, you never answered. This seems to be the way you operate around here.
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even if what tony claims was true (which it isnt) the core was far from complete or undamaged as shown by the videos
 
Gamolon said:
Really?

So when the engineers designed the towers and did their calculations, they designed the central core to be self supporting? They all sat around and said "Let's make sure that the core, comprised of 47 columns situated in an 87' x 137' rectangle and being 1300' tall, will be self supporting." I suppose you have these calculations handy or the quotes that state this as being so.

I'm really curious now. How do you know this? Did you do the calculations yourself and figure this out or do you have quotes from the actual design engineers saying this?

Also, did you ever find the quote from Skilling saying that he and his people did analysis concerning the effects of fire on the structural steel core? I see that when ai asked this of you many times, you never answered. This seems to be the way you operate around here.
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This is a video of WTC2. Even though they overlay a graphic of the core for a short time it is plain that the actual real core appears to be standing quite well on it's own.

http://video.google.com/videoplay?docid=-1615521411849861778 Core WTC2
http://images.google.nl/imgres?imgu...q=core+wtc2&gbv=2&ndsp=20&hl=en&sa=N&start=60 longer clip
 
Oh really?? If it was standing "quite well" on its own, why did it fall not long after that?? If the core was sulf-supporting, I would have been able to see it in any of the remaining days I was there. I, of course, didn't.

Why, when pointed out that you are horribly wrong, you still continue spewing nonsense???

Kinda like the "where's the core columns" thread?? Though, in your defense, you did give up on thata cherade.

I think you are on the same sinking ship that Heiwa is on. And it's Heiwa's fault if is sinking, because he is the one who designed it.
 
triforcharity said:
Oh really?? If it was standing "quite well" on its own, why did it fall not long after that?? If the core was sulf-supporting, I would have been able to see it in any of the remaining days I was there. I, of course, didn't.

Why, when pointed out that you are horribly wrong, you still continue spewing nonsense???

Kinda like the "where's the core columns" thread?? Though, in your defense, you did give up on thata cherade.

I think you are on the same sinking ship that Heiwa is on. And it's Heiwa's fault if is sinking, because he is the one who designed it.
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What do you think ? Was it like 'a dead man standing' or something like that ? Nah....gravity is instant- take away he support and an object wll fall all in one movement. On the other hand a standing frame of steel will stand or it will slowly deform at the bottom and fall longways. Definately not straight down. Explosives explosives explosives may be the answer that explains this. (or maybe thermite). But not gravity...
 
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