OOS Collapse Propagation Model

[Major_Tom]

The nose hits the middle column of the middle panel. That's pretty good flying.
..................................

NB, in just 3 pages you've managed to put not just one foot, but both feet in your mouth. Are you seriously going to persist in your claims about BV and BL?

We'll go over the papers section by section if necessary. You would be able to see some of the mistakes you are making by answering the following 4 questions:


1) In BL, can you explain why Dr Bazant insists that crush down must be complete before crush up occurs. Does he mean this literally?

2) Do you consider the equations of motion in BL, equations 12 and 17, to be accurate considering the information in the ROOSD study?

3) Is the following statement true or false:

Dr Bazant believes that a crush-down phase must continue to completion before a crush up phase can begin.

If you answer false, please provide evidence to the contrary.

4) Is ROOSD consistent the claims of crush down preceding crush up in BV and BL?


But if you want to drag this out, that's fine by me.
....................................

Guys, you don't have to be a genius to see major holes in BV and BL at this point.

If you have a sense of humor, the Bazant and Le paper is actually very funny in some parts. For me it is hard to believe anyone took this stuff seriously before, but when considering ROOSD, the earnestness behind some of the claims is just plain funny.

Consider from BL:

"So it must be concluded that the simplifying hypothesis of
one-way crushing (i.e., of absence of simultaneous crush-up),
made in the original paper, was perfectly justified and caused
only an imperceptible difference in the results. The crush-up
simultaneous with the crush down is found to have advanced
into the overlying story by only 37 mm for the North Tower
and 26 mm for the South Tower. This means that the initial
crush-up phase terminates when the axial displacement of
columns is only about 10 times larger than their maximum
elastic deformation. Hence, simplifying the analysis by neglecting
the initial two-way crushing phase was correct and
accurate."


Or how about this from BL:

"Blocks C and A can, of course, deform. Yet, contrary to
the discusser’s claim, they may be treated in calculations as
rigid because their elastic deformations are about 1,000 times
smaller than the deformations at the crushing front."


You have to wonder what world Dr Bazant was living in when he wrote this. Yet so many of you, without understanding any of what he is saying, without being able to follow the reasoning, without being able to use a Lagrangian formulation to solve equations of motion for the simplest systems, lecture me on it's meaning.

And you believe it because it was written in the JOURNAL OF ENGINEERING MECHANICS © ASCE / OCTOBER 2008, and you don't know any better.

 

[Newtons Bit]

And... I'm done with this truther. Major_Tom can admit that people were talking about non-buckled columns prior to him even joining here, then still claim that his idea is unique and special the next day.

I'm not going to go around and around with another reality changing truther like Heiwa.

 

[Newtons Bit]

That's wrong.
1) The "upper block" accelerates at about 6.6m/s^2 until reaching a terminal velocity.
2) The "rubble layer" isn't really a layer. It's more like an avalanche that (for WTC1) first becomes visible at about floor 85. These avalanches didn't accelerate at all. These avalanches moved at velocities of 25-27m/s downwards at different elevations. (Smaller avalanches e.g. between floor 85 and 75 in the center of the west face reached about 100m/s suggesting a quasi simultaneous collapse of the short trusses due to a partially core collapse.)
3) Despite the fact of the "missing" acceleration of theses avalanches the SE avalanche started at the same elevation like the front of falling debris outside of the building.
By simple logic it is obvious that either the rubble moved faster than the "upper block" or the falling debris was delayed or the rubble started at a lower elevation than the 98th floor.


That's wrong. A terminal velocity means force. It means also that any model of a consistent "upper block" is utter nonsense. Furthermore, Major Tom gave a pretty good description of what might have happen instead of some "hammer down" simplification. If true then these debris avalanches inside the tower separated the lions share of mass from the core. That explains the remaining part of the core pretty well. On the other hand it suggests that the missing part of the core either collapsed in front of the debris avalanches or at the very same time.


Well, that's wrong. Once more and more masses are separated from the core structure of both parts (as implied by the MT article) the weaker steel structure directly impacts the increasingly stronger steel structure (except the hat truss). So it is reasonable to expect an early complete destruction of the so called upper part.


Let's say, not one of the whole bunch of papers about a consistent upper block theory provided any shred of information how this probably could be correct.

I see you've managed to agree with me many times while still claiming to disagree with me.

 

[R.Mackey]

And... I'm done with this truther. Major_Tom can admit that people were talking about non-buckled columns prior to him even joining here, then still claim that his idea is unique and special the next day.

I'm not going to go around and around with another reality changing truther like Heiwa.

I don't think there's any other kind at this point.

Personally, I like how he seems to think Bazant and Le (2002) is supposed to be an accurate description of the collapse rather than a limiting case, or that he thinks that plus Bazant and Verdure (2006) cover the entire scope of the literature. As if we hadn't explained this to practically every Truther who ever lived a million times each.

Ah well. I guess it keeps them occupied, at least.

 

[Major_Tom]

Enlighten us, R Mackey. Can you answer these questions?

1) In BL, can you explain why Dr Bazant insists that crush down must be complete before crush up occurs. Does he mean this literally?

2) Do you consider the equations of motion in BL, equations 12 and 17, to be accurate considering the information in the ROOSD study?

3) Is the following statement true or false:

Dr Bazant believes that a crush-down phase must continue to completion before a crush up phase can begin.

If you answer false, please provide evidence to the contrary.

4) Is ROOSD consistent the claims of crush down preceding crush up in BV and BL?

Teach us how quotes like

"So it must be concluded that the simplifying hypothesis of
one-way crushing (i.e., of absence of simultaneous crush-up),
made in the original paper, was perfectly justified and caused
only an imperceptible difference in the results. The crush-up
simultaneous with the crush down is found to have advanced
into the overlying story by only 37 mm for the North Tower
and 26 mm for the South Tower. This means that the initial
crush-up phase terminates when the axial displacement of
columns is only about 10 times larger than their maximum
elastic deformation. Hence, simplifying the analysis by neglecting
the initial two-way crushing phase was correct and
accurate."

Represent a limiting case.

 

[Myriad]

Bazant's model is a limiting case representing the most favorable assumptions for collapse arrest. Among those assumptions is that all the weight of the falling mass -- even the already crushed and broken rubble -- somehow lands squarely on columns.

In that model, meaning under those assumptions, crush-down precedes crush-up. Bazant shows how and why.

The extent to which crush-down did not precede crush-up in the actual collapse indicates only that those favorable assumptions for collapse arrest were not true, so collapse arrest was even more impossible.

Try this analogy, Major Tom: suppose you're skydiving and your chute fails to open. Bazant, who happens to be looking on, quickly assesses the situation and says, "His best chance to survive is if he lands on that giant pile of mattresses over there. But even then, my calculations say the landing will kill him." You respond (since you have nothing better to do whilst plummeting earthward), "Ha! I'm landing nowhere near those mattresses! In fact, I'm heading right for that Upright Steel Spikes Inc. storage yard 1000 feet west instead. You believe I'm going to land on the mattresses but the facts contradict you. So your prediction that I'm going to die has no validity!

At that point Bazant rightly figures that there's no point in saying anything further. Why bother to argue with someone who thinks that proving a situation is worse than the best-case scenario somehow means that one should expect better than the best-case outcome?

Respectfully,
Myriad

 

[bio]

(...) Among those assumptions is that all the weight of the falling mass -- even the already crushed and broken rubble -- somehow lands squarely on columns.

In that model, meaning under those assumptions, crush-down precedes crush-up. Bazant shows how and why.

(...)

When the falling mass was "crushed and broken rubble", then crush-up had taken place! How can you say then in the next sentence, that with that assumption crush down precedes crush-up?

 

[Myriad]

When the falling mass was "crushed and broken rubble", then crush-up had taken place! How can you say then in the next sentence, that with that assumption crush down precedes crush-up?

Why does rubble imply crush-up? You seem to be assuming that falling rubble could only come from pieces of the falling upper block, but there is no reason to assume any such thing. Rubble comes from whatever is being crushed. Crush-down produces rubble. The crushed and broken rubble falls due to being pushed down by the falling upper block, and/or being itself acted upon by the earth's gravitational field.

Respectfully,
Myriad

 

[bio]

Why does rubble imply crush-up? You seem to be assuming that falling rubble could only come from pieces of the falling upper block, but there is no reason to assume any such thing. Rubble comes from whatever is being crushed. Crush-down produces rubble. The crushed and broken rubble falls due to being pushed down by the falling upper block, and/or being itself acted upon by the earth's gravitational field.

Respectfully,
Myriad

okay - the rubble "from the falling mass" does not come from the upper block.

 

[Dave Rogers]

okay - the rubble "from the falling mass" does not come from the upper block.

Where do you think the rubble from the lower block goes?

Dave

 

[bio]

Where do you think the rubble from the lower block goes?

Dave

yes - down.

it is incredible, what you guys are saying. Everybody can see in the videos, that there is no "rigid" upper block, it was crushed into rubble, everybody can see that. How can you tell otherwise?

Never before, the craziness of this official paradigm has become so clear.

 

[Dave Rogers]

yes - down.

So the rubble from the lower block still exists in your world. That's a relief. Now, what's wrong with that being the source of the majority of the rubble forming layer B?

If you were to actually read Bazant's papers for comprehension, rather than deciding what strawman you want to attribute to them, you would see that the analysis predicts that crush-up and crush-down will initially both occur, but that the rate of crush-up will quickly decay to zero while the rate of crush-down increases. This is an idealised case, and the presence of damage to the structure above or below the collapse initiation zone will modify the precise amount of crush-up initially observed, but at no point is Bazant claiming that there is no crush-up until crush-down is complete; he's determining that a very small amount of initial crush-up occurs, but that it self-terminates until the upper block contacts the ground. As a result, a small proportion of the rubble comes from the upper block, and the majority from the lower.

it is incredible, what you guys are saying. Everybody can see in the videos, that there is no "rigid" upper block, it was crushed into rubble, everybody can see that. How can you tell otherwise?

Funnily enough, no, the rest of us can't see that, because the dust ejected by the collapse obscures vision of the upper block part way into the collapse. Since we can't tell what happens to things we can't see, we can either make up something that fits our prejudices or model the physics of the collapse mathematically and draw provisional conclusions. The first approach seems to be working very nicely for you, to the extent that you've convinced yourself you can see something that's hidden in a dust cloud. For the rest of us, we'd rather start from what we can see then decide on a conclusion, than start from a conclusion then decide what we can see.

Dave

 

[bio]

(...)


Funnily enough, no, the rest of us can't see that, because the dust ejected by the collapse obscures vision of the upper block part way into the collapse. (...)

that is obviously not the truth.

The upper block of WTC-1 went down and a big part crashed into rubble in the first seconds of collapse. There, in the first two seconds of collapse, was no big dust cloud, which hindered the vision.

 

[bio]

(...)

If you were to actually read Bazant's papers for comprehension, rather than deciding what strawman you want to attribute to them, you would see that the analysis predicts that crush-up and crush-down will initially both occur, but that the rate of crush-up will quickly decay to zero while the rate of crush-down increases. This is an idealised case, and the presence of damage to the structure above or below the collapse initiation zone will modify the precise amount of crush-up initially observed, but at no point is Bazant claiming that there is no crush-up until crush-down is complete; he's determining that a very small amount of initial crush-up occurs, but that it self-terminates until the upper block contacts the ground. As a result, a small proportion of the rubble comes from the upper block, and the majority from the lower.

(...)

I make up nothing, I just cited Myrad "Why does rubble imply crush-up? You seem to be assuming that falling rubble could only come from pieces of the falling upper block, but there is no reason to assume any such thing."

So Myrad is debunked by a fellow debunker

According to you, there was crush up but only at the beginning and with a "very small amount". Why?

 

[Myriad]

Once again (well probably more, but once at a time): I make no claims about which block the rubble came from in the actual collapses. I merely point out that in Bazant's model, as a direct result of making the assumptions most favorable to collapse arrest, crush-down diverges from crush-up very early in the process and crush-down then predominates until the upper block reaches the ground.

If the actual collapses behaved differently, all that means is that the process was less favorable to collapse arrest than Bazant assumed as a limiting case. So collapse arrest was impossible by an even wider margin.

Of course we already knew this, because that's what analyzing a limiting case means.

The bottom line is, nothing offered in this thread helps any known Truther argument in any way whatsoever.

Respectfully,
Myriad

 

[Dave Rogers]

that is obviously not the truth.

The upper block of WTC-1 went down and a big part crashed into rubble in the first seconds of collapse. There, in the first two seconds of collapse, was no big dust cloud, which hindered the vision.

You're changing your story now, are you? You were claiming that the top block was smashed into rubble; now you're saying that 'a big part' was smashed into rubble, and that you only saw the first two seconds. At the end of that two seconds, there was still a large part of the upper block intact, and you don't know what happened to it after that because you couldn't see it. So your observation - now you've admitted to what you actually observed, rather than what you initially claimed you observed - is in fact completely consistent with an initial limited amount of crush-up, followed by primarily crush-down.

I make up nothing, I just cited Myrad "Why does rubble imply crush-up? You seem to be assuming that falling rubble could only come from pieces of the falling upper block, but there is no reason to assume any such thing."

I suggest you look up the meaning of the word 'only'. Myriad is pointing out that some or all of the rubble could come from the lower block, which you've now admitted, and that therefore the existence of rubble doesn't imply crush-up, which is elementary logic.

According to you, there was crush up but only at the beginning and with a "very small amount". Why?

This is from Bazant's papers, which I suggest you re-read (I forget which one, but it won't hurt you to re-read them all).

Dave

 

[bio]

Enlighten us, R Mackey. Can you answer these questions?

1) In BL, can you explain why Dr Bazant insists that crush down must be complete before crush up occurs. Does he mean this literally?

2) Do you consider the equations of motion in BL, equations 12 and 17, to be accurate considering the information in the ROOSD study?

3) Is the following statement true or false:

Dr Bazant believes that a crush-down phase must continue to completion before a crush up phase can begin.

If you answer false, please provide evidence to the contrary.

4) Is ROOSD consistent the claims of crush down preceding crush up in BV and BL?

Teach us how quotes like

"So it must be concluded that the simplifying hypothesis of
one-way crushing (i.e., of absence of simultaneous crush-up),
made in the original paper, was perfectly justified and caused
only an imperceptible difference in the results. The crush-up
simultaneous with the crush down is found to have advanced
into the overlying story by only 37 mm for the North Tower
and 26 mm for the South Tower. This means that the initial
crush-up phase terminates when the axial displacement of
columns is only about 10 times larger than their maximum
elastic deformation. Hence, simplifying the analysis by neglecting
the initial two-way crushing phase was correct and
accurate."

Represent a limiting case.

I support you in asking these straight forward questions.

 

[Major_Tom]

I'm very glad other posters have came out to defend the BV and BL papers.

Dave, In BL, can you explain why Dr Bazant insists that crush down must be complete before crush up occurs. Does he mean this literally?

R Mackey seems to be saying he doesn't mean this to apply to WTC1 literally.

What do you think?

This is from Bazant's papers, which I suggest you re-read (I forget which one, but it won't hurt you to re-read them all).

That is in BL and I suggest all of you who wish to participate reread it carefully. You'd save me some time if you do.

 

[bio]

You're changing your story now, are you? You were claiming that the top block was smashed into rubble; now you're saying that 'a big part' was smashed into rubble, and that you only saw the first two seconds. At the end of that two seconds, there was still a large part of the upper block intact, and you don't know what happened to it after that because you couldn't see it. So your observation - now you've admitted to what you actually observed, rather than what you initially claimed you observed - is in fact completely consistent with an initial limited amount of crush-up, followed by primarily crush-down.

(...)

A big part of the upper block was smashed into rubble for sure, then comes the dust cloud. What is rational to assume?
- that the rest of the upper block stayed intact and smashed the block underneath it.
- that the rest of the upper block was destroyed, too.

 

[bio]

I'm very glad other posters have came out to defend the BV and BL papers.

Dave, In BL, can you explain why Dr Bazant insists that crush down must be complete before crush up occurs. Does he mean this literally?

R Mackey seems to be saying he doesn't mean this to apply to WTC1 literally.

What do you think?



That is in BL and I suggest all of you who wish to participate reread it carefully. You'd save me some time if you do.

I really support your inputs here. I want to know eventually, what the official collapse theory is about.