OOS Collapse Propagation Model

[JSanderO]

The posts of mine from four years ago that M_T recently quoted were explicitly arguing that Bazant's model was not literal. Which at the time, M_T strenuously disagreed with (and as far as I can tell, still does).

What M_T appears to be trying to get us to counterfactually acknowledge is two separate points: one, that Bazant's models were intended to be literal and provide an authoritative account of how the collapse actually occurred; and two, that we all accepted that authoritative account (double-hinged columns and all) as how the collapse actually occurred, prior to M_T's "ROOSD" coinage.

The fact that we were arguing against the first claim four years ago, as shown in the early passages he keeps quoting, he is somehow trying to use as evidence that the second claim is correct, when it's actually quite strong evidence against it.

Equally bewilderingly, JS_O also continues to argue for the second claim contrary to that and multiple other lines of evidence. Including, for instance, the physical model of the collapse mechanism I proposed a year before this thread started, in which the mechanism of collapse propagation was explicitly expected to be progressive failure of the connections between the model floors and their upright supports.

There may be some ecdysiast potentates around here somewhere, but they aren't Bazant, Newton's Bit, R. Mackey, Dave Rogers, GlennB, DGM, jaydeehess, tsig, JUtah, rwguinn or me.

Doesn't matter to me what you were arguing about years ago. The towers came down as falling mass of building parts drove downward taking out floors and sections of floors... not entire slabs at one fell swoop... one after the other leaving both the facade and the core unbraced and unstable.

 

[DGM]

Doesn't matter to me what you were arguing about years ago. The towers came down as falling mass of building parts drove downward taking out floors and sections of floors... not entire slabs at one fell swoop... one after the other leaving both the facade and the core unbraced and unstable.

No one thought this was the case. Unless you take a TV explanation literally.

I hate to say it but, maybe you missed the science because you were looking for a "better" explanation? You did fall for Gages nonsense.

 

[Newtons Bit]

Doesn't matter to me what you were arguing about years ago. The towers came down as falling mass of building parts drove downward taking out floors and sections of floors... not entire slabs at one fell swoop... one after the other leaving both the facade and the core unbraced and unstable.

Of course it matters when you're asking us to call a "spade a spade" when the bulk of us were doing it years before Major_Tom invented the term "ROOSD" and never had any misunderstanding as to what Bazant's various papers were in fact about.

 

[tsig]

Of course it matters when you're asking us to call a "spade a spade" when the bulk of us were doing it years before Major_Tom invented the term "ROOSD" and never had any misunderstanding as to what Bazant's various papers were in fact about.

It took me quite a while to understand M_T's point since I couldn't imagine that someone would base his argument on the fact that a paper that didn't intend to be a detailed analysis was not a detailed analysis.

Rather like blasting a Chevy Vega for not winning the Indy 500.

 

[Myriad]

Doesn't matter to me what you were arguing about years ago.

Yet it obviously matters to you enough to make this claim:

... and I suppose he was so heavily touted as the go to guy it's odd that people appear to refuse to say his work was not an explanation for the collapses as they apparently had touted it to be in the past.

The way your "doesn't matter" response comes across to me is, it matters enough for you to make claims (of unclothed emperors, of not calling a spade a spade, of skeptics refusing to acknowledge something that we've actually been saying since before the start of the thread), but not enough for you to care that those claims are false.

That's a rather poor show, I'm afraid.

 

[carlitos]

Yet it obviously matters to you enough to make this claim:




The way your "doesn't matter" response comes across to me is, it matters enough for you to make claims (of unclothed emperors, of not calling a spade a spade, of skeptics refusing to acknowledge something that we've actually been saying since before the start of the thread), but not enough for you to care that those claims are false.

That's a rather poor show, I'm afraid.

Keep in mind that he could care less. Not sure by how much.

 

[WilliamSeger]

Keep in mind that he could care less. Not sure by how much.

I think I'll start saying, "I couldn't care a lot less," to be as precise as possible.

 

[rwguinn]

I could care less, but it would be too much effort.

 

[Major_Tom]

The posts of mine from four years ago that M_T recently quoted were explicitly arguing that Bazant's model was not literal. Which at the time, M_T strenuously disagreed with (and as far as I can tell, still does).

What M_T appears to be trying to get us to counterfactually acknowledge is two separate points: one, that Bazant's models were intended to be literal and provide an authoritative account of how the collapse actually occurred; and two, that we all accepted that authoritative account (double-hinged columns and all) as how the collapse actually occurred, prior to M_T's "ROOSD" coinage.

The fact that we were arguing against the first claim four years ago, as shown in the early passages he keeps quoting, he is somehow trying to use as evidence that the second claim is correct, when it's actually quite strong evidence against it.

Equally bewilderingly, JS_O also continues to argue for the second claim contrary to that and multiple other lines of evidence. Including, for instance, the physical model of the collapse mechanism I proposed a year before this thread started, in which the mechanism of collapse propagation was explicitly expected to be progressive failure of the connections between the model floors and their upright supports.

There may be some ecdysiast potentates around here somewhere, but they aren't Bazant, Newton's Bit, R. Mackey, Dave Rogers, GlennB, DGM, jaydeehess, tsig, JUtah, rwguinn or me.

Thanks for the 2014 update. I'll add it to the list of quotes on BV.

I am recording historic revisionism of the written record in action live on JREF. I'm finding the current exchange to be a a goldmine of information on how BV, BL, and BLGB are still perceived within this environment in 2014.

 

[Major_Tom]

In my poll ROOSD stands ahead of column overloading by a margin of 24/5 right now. So I don't think JU was referring to M_T's ROOSD position.

In fact M_T's most recent post never mentions it. Instead he goes on, again, about posters misunderstanding not his own position that ROOSD drove progression of collapse, but refers to other posters misunderstanding Bazant's papers.

M_T seems more interested in discussing Bazant than he does his own paper.

I am very interested in historic revisionism in relation to the WTC collapses. That is what my book is about. That is what is happening within the environment of this forum but the group seems completely unaware that this is happening.

A small collection of repeated memes within this environment has replaced the capacity to think critically about BV, BL, and BLGB. Those propagating the memes are not necessarily insincere but they are incapable of perceiving what they are doing.

 

[beachnut]

Thanks for the 2014 update. I'll add it to the list of quotes on BV.

I am recording historic revisionism of the written record in action live on JREF. I'm finding the current exchange to be a a goldmine of information on how BV, BL, and BLGB are still perceived within this environment in 2014.

Wow, will this be part of the "just plain idiots" super anti-technical no math study gossip claptrap?

How is the BS of the "gravity collapse is an illusion" going, is that part of the revisionism? Is the gravity collapse still an illusion, I gots to knows, I am working on 911 truth's failed claims historic revisionism based on no math, no engineering, and an ignorance of models, and found the "just plain" stuff are a goldmine for BS.

Who did 911 in your recording of historic revisionism? lol

 

[jaydeehess]

I am very interested in historic revisionism in relation to the WTC collapses. That is what my book is about. That is what is happening within the environment of this forum but the group seems completely unaware that this is happening.

A small collection of repeated memes within this environment has replaced the capacity to think critically about BV, BL, and BLGB. Those propagating the memes are not necessarily insincere but they are incapable of perceiving what they are doing.

So the title of this thread is at best misleading and at worst, in error.

As I said before , I for one , am completely disinterested in your amateur psychobabble and your personal perception of other's perceptions.

I am also disinterested, as are others , in political musings for much the same reason, that being I prefer technical discussion and in that your 'book' has some interesting bits.

So, your 'book' is supposedly primarily about an examination of the perception of Bazant.

It is noted though, that even those posters who you feel don't have a correct perception of those of his papers that do suggest he believes in column buckling led progression, do not themselves believe that column buckling was the primary driver of progression.

So,,,,, where's the significance in this?

 

[Reactor drone]

I am very interested in historic revisionism in relation to the WTC collapses. That is what my book is about.

Yes, we've always been at war with Eastasia, never Eurasia.

 

[DGM]

Thanks for the 2014 update. I'll add it to the list of quotes on BV.

I am recording historic revisionism of the written record in action live on JREF. I'm finding the current exchange to be a a goldmine of information on how BV, BL, and BLGB are still perceived within this environment in 2014.

You are recording examples of your own as well, right? Someone might get the wrong idea if you didn't include your posts these "revisions" were in response to. You should also record your response to the questions asked of you in some of these "revisions".

Somehow, I get the feeling you'll "encourage" the readers of the "book" to discover this on their own.

 

[WilliamSeger]

I am recording historic revisionism of the written record in action live on JREF. I'm finding the current exchange to be a a goldmine of information on how BV, BL, and BLGB are still perceived within this environment in 2014.

I couldn't care a lot less about that, but on page 1 you said, "It does belong here because once the model is accepted, we can examine conclusions in view of CD. Please give me some time to show that. I need to get through the initial resistance first."

Any ETA?

 

[LSSBB]

Thanks for the 2014 update. I'll add it to the list of quotes on BV.

I am recording historic revisionism of the written record in action live on JREF. I'm finding the current exchange to be a a goldmine of information on how BV, BL, and BLGB are still perceived within this environment in 2014.

Yes, I understand Nixon kept a similar record of his enemies actions. Let me know how that turns out for you, and what help it provides in the search for clarity regarding the WTC1 and WTC 2 collapses. Hopefully for you such an approach works better in Engineering activites than it did in politics. However I must admit I do remain skeptical.

 

[ProBonoShill]

I am very interested in historic revisionism in relation to the WTC collapses. That is what my book is about. That is what is happening within the environment of this forum but the group seems completely unaware that this is happening.

A small collection of repeated memes within this environment has replaced the capacity to think critically about BV, BL, and BLGB. Those propagating the memes are not necessarily insincere but they are incapable of perceiving what they are doing.

That's hilarious coming from someone who believes explosives were responsible for the collapses, but desperately tries to hide that fact.

Speaking of thinking critically "about BV, BL, and BLGB" when will you be submitting a critique of their work for publication in a respected journal?

 

[Major_Tom]

In summary of previous posts, I strongly recommend approaching analysis of the BV, BL, and BLGB papers through the following 7 perspectives:



1) Direct comparision between Bazant and Seffen methods and their key equations of motion (Seffen eq 12 compared to Bazant eqs 12 and 17).

2)) A basic study of 1-dimensional stacked system collision interactions with a variety of parameters altered linked here. This gives one a simple, practical sense of 1-dimensional multiple body interactions, like the type described in BV eqs 12 and 17, and the possible varieties of mechanical movements that can result from them.

3) Direct comparison of claims within BV to the actual collapse propagation rates which were recorded after the 2007-2008 Bazant papers were written.

4) Quotes by David Benson demonstrating how he understood the relationship between BV eqs 12, 17 and the actual collapses of WTC1, 2 linked here

5) Statements by Bazant in BL (the closure to BV) and BLGB demonstrating how he understood the relationship between BV eqs 12, 17 and the actual collapses of WTC1, 2.

6) Comparison of statements about WTC1 and 2 made within BV, BL, and BLGB directly with the visual record of events through the lens of the most accurate mappings of the WTC1, 2 collapse behavior (available in parts 2.1, 2.2, 2.3, and 2.4 of my book).

7) Practical comparison of BV eqs 12 and 17 and Seffen eq 12 to video records of Verinage demolitions.








Also, in sharp contrast to both Bazant and Seffen, I strongly recommend approaching the physics and mathematics of the WTC1 and 2 collapse propagations using these 5 steps in order:


Step 1: GAIN AN OVERALL CONCEPTUAL AND VISUAL UNDERSTANDING OF WHAT ONE IS LOOKING AT

Step 2: RESEARCH AVAILABLE LITERATURE ON THE SUBJECT OF FLOORS IMPACTING FLOORS

Step 3: MEASURE THE COLLAPSE PROPAGATION RATE AS ACCURATELY AND COMPLETELY AS POSSIBLE

Step 4: EXAMINE A VARIETY OF PHYSICS-BASED MATHEMATICAL APPROACHES TO THE COLLAPSE OF STACKED SYSTEMS

Step 5: COMPARE MODELS IN STEP 4 TO INFORMATION IN STEPS 1 - 3 to see which models could match propagation behavior or teach something about it.



I learned from experience and by watching others that if one skips any of these steps, their analysis is bound to run into problems of which they probably won't be aware.

 

[Major_Tom]

In contrast to my approach, for reference purposes I've compiled an overall summary of how the BV, BL, BLGB papers and the OOS propagation model are perceived within this environment of JREF. (These quotes are from p 1-13):

This failure mode has been discussed for a very large period of time and it just a rehash of what everyone who wasn't delusional already knew.

Bazant and Verdue states that, "The kinetic energy of the top part of the tower impacting the floor below was found to be about 8.4 larger than the elastic energy absorption capability of the underlying story," and the the purpose of the Bazant and Verdue paper is not to describe the WTC collapse, but rather to create "a theory describing the progressive collapse dynamics" as this would be "very useful for other purposes, especially for
learning from demolitions".

If any thing, his "paper" only provides evidence as to why the collapse was quicker than expected in the axial column-to-column scenario.

Haven't read the paper, but are you planning to get it published in an engineering journal?

Bazant and Verdue sets out to model and understand progressive collapse. Not prove how the WTC collapsed. It uses the WTC only as a paradigm. I.e. an example, a model, a pattern, etc etc. It then applies the conclusions of this model to other buildings, as that is the stated purpose of this model.

Major_Tom wants to argue against a strawman Bazant. Repeated quotes from the paper (some of which he has provided) doesn't seem to persuade him that he is looking at the papers wrong. He also wants to say that he's the first person to come up with the idea of the columns not hitting each other.

You're moving the goalposts. We've been talking about the claim of axial-column impacts. Not the crush-up / crush-down hypothesis.

Incidentally, you haven't done anything to debunk crush-up / crush-down. Even in a floor failing model, crush-up / crush-down still applies due to the simple fact that there is very little force being applied to the upper block. The rubble layer is still doing all the destruction.

Your paper is junk... Complete nonsense. You make up junk out of thin air like Jones. What kind of engineer are you?


What is your goal? Is your goal to support the insanity of Jones, or the fraud of Gage? You want the cult member of these two fringe nut case conspiracy theorists to discuss more nonsense about 911?

You are a lying liar. We challenged you on your fraudulent claim on the buckled columns concept. YOU brought up the upper block / lower block. This is a non-sequitur. It would make an equal amount of sense for you to bring up Bazant's middle name as an argument. Unfortunately, the way you do it you just come across as a dishonest charlatan. Which, by the way, you are.

Your paper is nonsense. I am an engineer who supervised projects for the USAF, my assessment is based on 36 years of experience. There is no value at all to your paper.
I delivered. You are welcome.

The whole line of investigation is ridiculous. What unanswered question does this paper purport to examine? None. Existing, reliable, reviewed scientific literature covers it quite thoroughly. All the made-up acronyms and appeals for attention are no more than fatuous Truther narcissism.

The upper block is accelerating at near g. This means that there is very little force being applied to it. We can imply that the absolute maximum height of destruction occurring through the upper block will happen at a rate equal to (g - a). However the upper block has some residual strength. This force is much less than the original capacity uzxpper block which is somewhere in the neighborhood of 3*m*g.

There will be, during the initial stages of the collapse that forms the rubble layer, destruction on both the upper block and lower block. But once it gets moving? Not so much.

You've provided no information on how this is incorrect.

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.

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.

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.



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.

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.

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.


....

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).

Why the obsession with Bazant? It was written within a few days doesn't represent a full analysis,

Bazant showed that initial crush-up would arrest very quickly, and that in effect the upper block would ride down on the intervening rubble block as it destroyed the lower structure. This is for the specific case of a perfectly level collapse with axial column-on-column impacts of a previously undamaged structure, which is the limiting case Bazant used to determine whether it was possible for the structure to resist collapse.

....

As everyone keeps pointing out ad nauseam, Bazant is considering the limiting hypothetical case in which the structure is best able to resist collapse, and finding that it cannot.



Neither. Without some kind of modelling the only rational assumption would be that we don't know whether the crush-up of the upper block continued, and anything more would be a guess. Since the only case that's been analysed indicates that crush-up is expected to arrest, then it's reasonable to assume that that was the case in reality.

It's much worse than that. Bazant and Le Zhou was written within 48 HOURS of the incident.

He is applying it to his model of a WTC tower, which incorporates best-case assumptions for the possibility of collapse arrest. That he is analyzing a model is indicated by the methodology used -- which is performing mathematics on the model, as opposed to, say, running up and down the tower with a tape measure as it was collapsing.

In other words, complete crush-down preceding significant crush-up is not an arbitrary assumption imposed on the best-case model to simplify the calculations, it is also a result derivable from analysis of the best-case model.

If it could be shown with actual evidence that crush-down did not in fact precede crush-up in the real event, all that would mean is that the real case was far worse, in terms of the likelihood of collapse arrest, than the assumed best case. (Which we already knew, because for most of the collapse, the load sheared floors from the columns instead of buckling the columns, reducing the actual amount of energy absorbed in inelastic strain to only a small fraction of the maximum theoretically possible).

Another cautionary word, though: Bazant and Verdure's model is a simplified one-dimensional homogeneous approximation to the behaviour of a real building, which is intended to reproduce gross features of collapse behaviour. Any attempt to apply it to the detailed features of collapses of specific, three-dimensional, inhomogeneous and (most importantly) already locally damaged buildings is absolutely certain to fail.

My parents sent me to engineering school and the USAF to engineering grad school, it helps me see quickly the BS Major Tom's paper is. Anyone with a grade school education can figure it out also, my training is not needed to call BS on Major Tom's work; why can't you figure it out?

I cited the paper that contains the answer to the question you asked regarding whether Bazant intended the assumptions made in his collapse model of the WTC towers to represent a limiting best (most favorable to collapse arrest) case. In the paper in which he introduced that model and first applied it to the WTC collapses, he clearly stated that it was (using the phrase "most optimistic.") That paper is cited in "BV" so presumably Bazant still stands by its claims; nor does he need to repeat that information in "BV," having cited it.

What is this bizarre game you're playing with "answer my question using only the paper I tell you to?" Can I play too? What's the capital of Michigan, and please back up your answer using only passages from Shakespeare's prime numbered sonnets. Thanks!

What you're doing, typical of the more inane Truthers, is performing an extremely slow, dull-witted, and well-telegraphed Shifting the Burden of Proof and Begging the Question logical fallacy. Dr. Bazant's papers do precisely what they were intended to do. You are trying to show they are inadequate for a purpose they were never intended, and is not needed in the first place. What a waste of time.

Will you follow the scientific method in your study? Yes or no?[/B]

So far, what you've done does not follow the Scientific Method at all.

The question you've asked is a scientific one. Yet you don't even know what the scientific method is. That pretty much irretrievably defines you as a consummate fraud.

There are no flaws, unknowns or disagreements among relevant investigators that are resolved by proposing that anything but fire was the fundamental cause of the collapse of WTC1/2/7.

1. Where's the math?

Where do you give any calculations proving.....well.....anything?

2. Where's the physics?

Where do you give any principles of physics proving.....well....anything?


Your papers seem to be a combination of complaining, crying, assuming, and imagining....

Is there some, you know, math and physics in there somewhere?

Math and physics are kinda important to writing something related to engineering.....don't you think?

And what would you expect to see (in reality) when the outer walls, floor spans and some of the core beams were demolished, while exposed core columns that now lack adequate horizontal bracing are being impacted laterally by a mountain of falling debris?

That a section of core would be the last thing to fall. And this is exactly what happened.

Bazant deliberately chose a collapse model that gave the greatest chance of resisting collapse - a 'pure' axial column-to-column impact. Anything else would be even more damaging. He understood the structure perfectly well.

Contradicts? In what way?

I think you're missing the point again and again.

From my reading of the thread, but apparently not from yours, Bazant's model is based on the most favorable case for collapse arrest, and it's in this case where the crush-down/crush-up happens. Since the real scenario is different to the model, then some crush-up is possible because it's not what Bazant modeled.

That's no contradiction; the existence of some crush-up would merely prove that the real collapse was not so favorable to collapse arrest as Bazant's model.

Now, does your paper prove, with engineering arguments, that Bazant's model is not the most favorable to collapse arrest? If that was case you would have something that could refute him.

 

[DGM]

Also, in sharp contrast to both Bazant and Seffen, I strongly recommend approaching the physics and mathematics of the WTC1 and 2 collapse propagations using these 5 steps in order:

Are you talking about for purpose of actual or conceptual (modeling)? If you include conceptual you need to include the purpose of the model or concept being studied.