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OOS Collapse Propagation Model

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That part is called the "crush-up phase", NB.

Crush-down, then crush up.

When crush down is complete, crush up begins.


Crush down is eq 12. Crush up is eq 17.


Are you grasping this?

Hold on. Are you ... are you seriously making an argument from the order in which the equations are presented?
 
The misrepresentations of BV began in 2010, page 1 of the thread, and the same misrepresentations and beliefs continue to this page.

They have never been corrected and they are still being fed page after page.
 
Generally, M_T's ROOSD theory is only important to me if M_T shows it is important.

I did bring ROOSD up as a counterexample to Tony Szamboti's assertion that there was no other theory of collapse besides his own and Bazant. Were M_T published, I would have had a stronger argument against Tony,

So you cannot find any representation of the ROOSD process within published literature?

I have been pointing out the same thing.
 
See what I mean? The misrepresentations never end.

This is what physicist Daviid Bohm calls 'sustained incoherence.'

Rather than simply brushing me aside, as though I have been misrepresenting something from the start, perhaps you could deign to correct my misrepresentation or, at the least, point it out so that I can correct it. It may astonish you to realize this, but I have had no prior participation in this thread and, thus, am not subject to your desperate digging for historical quotes that you feel are somehow indicative of other posters' lack of intellectual integrity.
 
Hold on. Are you ... are you seriously making an argument from the order in which the equations are presented?

See what I mean? The misrepresentations never end.
Yes, indeed: Major_Tom's misrepresentations of others' views have continued for four years, and show no sign of ending.

For quite a while now, Major_Tom has been repeating variations of "BV is really, really important to some of you and some of you will stop at nothing to believe in it", ignoring explicit denials by those accused and disregarding specific evidence from forum archives that contradict his claim.

Major_Tom continues to insist that "As of October 20, 2014, only one regular poster, Ozeco, could find and admit to mistakes in BV", even after I quoted posts from two and (almost) four years ago in which I pointed out that BV contains a fairly obvious mathematical error.

This is what physicist Daviid Bohm calls 'sustained incoherence.'
Yes, indeed. Major_Tom's entire approach to the topic of this subforum has provided a good example of the "sustained incoherence" David Bohm was talking about:

David Bohm said:
You may say "I see a problem here, so I will bring my thoughts to bear on this problem". But "my" thought is part of the system. It has the same fault as the fault I'm trying to look at, or a similar fault.

Thought is constantly creating problems that way and then trying to solve them. But as it tries to solve them it makes it worse because it doesn’t notice that it's creating them, and the more it thinks, the more problems it creates.
 
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See what I mean? The misrepresentations never end.

Indeed:

I've modified the ROOSD model to include a simple 5 step mathematical approach to ROOSD propagation.

The complete ROOSD model is described in the links below


....2.1: Progressive Floor Collapses in the WTC Towers
....2.2: General Global Characteristics of Collapses
....2.3: Mathematical Basis of ROOSD Propagation

BV is really, really important to some of you and some of you will stop at nothing to believe in it.
 
Major_Tom continues to insist that "As of October 20, 2014, only one regular poster, Ozeco, could find and admit to mistakes in BV", even after I quoted posts from two and (almost) four years ago in which I pointed out that BV contains a fairly obvious mathematical error.

You are saying there are 2 regular posters who could admit to mistakes in BV, Ozeco and you?

Can you see how BV and the closure BL misrepresent the collapse progression processes of WTC1? Or is it just an error in a single equation that you spotted?
 
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Rather than simply brushing me aside, as though I have been misrepresenting something from the start, perhaps you could deign to correct my misrepresentation or, at the least, point it out so that I can correct it. It may astonish you to realize this, but I have had no prior participation in this thread and, thus, am not subject to your desperate digging for historical quotes that you feel are somehow indicative of other posters' lack of intellectual integrity.

Are you sure you haven't posted in this thread earlier?

BV eq 12 is used before eq 17 is applied. Your earlier comment:

Hold on. Are you ... are you seriously making an argument from the order in which the equations are presented?

Your comment makes no sense. The order is explicitly stated in the paper.
 
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You are saying there are 2 regular posters who could admit to mistakes in BV, Ozeco and you?
More precisely: WDC is saying that there are at least 2 regular posters who could admit to mistakes in BV, Ozeco and him, while YOU, M_T, claimed that there is only 1 such poster, ozeco41.
In other words: That you made a FALSE statement even though the evidence you needed to correct your MISTAKE was right before your eyes.

Now would you please get down on your knees, eat dirt, put on a miserable face, and admit to having made a mistake there. Please confess your sins in the form and style that you expect us to confess ours. :rolleyes:

Can you see how BV and the closure BL misrepresent the collapse progression processes of WTC1? Or is it just an error in a single equation that you spotted?
WDC addressed this already, but where ... wait while I am looking ... oh, it's linked to right from the very same post that you just quoted:
So far as I can tell, the main problem with BV is the plausibility of their model, which lies outside my competence.
WDC made that comment on Jan 6, 2011. Almost 4 years ago.

Perhaps if you stopped the misrepresentations; and if you stopped to insist on derailing this thread so as to make it about WDC or myself, and if instead you refocused on the future in which you might eventually and actually present a mathematical approach to ROOSD, perhaps then this thread will make progress.
 
Here is the first post from page 64, when M_T was still, and actually, attempting to provide a mathematical approach to ROOSD.
Mathematical approach to ROOSD as progressor
Let's pick up there and go bit by bit:
Fundamental conditions:

for rubblized driving mass > M(1) moving at a downward velocity > V(1) , the runaway process is assured. The threshold conditions require a minimum M(1) traveling downward at velocity V(1).
Assuming that you haven't determined any specific values (numbers) for M(1) and V(1) for both or either WTC1 or WTC2, do I take it that you hypothesize that for any suitable building there is such a set of values, and that this can in principle be found using either math or observation?

Does "fundamental condition" mean that with M < M(1) or V < V(0), ROOSD will not happen?

How (or where - link will do) did you derive that the fundamental conditions are these two values and not, for example, their product (M*V) oder the kinetic energy implied by the numbers (0.5*M*V2) - or some other such relationship?

The process requires progressive and runaway breakability of successive floor-to-column connections.
Not sure I understand this correctly.
What is "progressive and runaway breakability of successive floor-to-column connections"?
Does this mean that each successive connection must have a property called "runaway breakability" plus a a property called "progressive breakability"? And what on earth would that property mean??

Examination of available literature: None

Measurements and observations of a first known documented case: WTC1 and 2 (roofline and collapse front)
...
[snipped links and stuff with measurements. Result:]
...
I skip this longish part and just acknowledge it's there and has been carefully crafted. I accept for the moment without argument that your measurements are correct, relevant, sufficiently accurate and sufficiently complete (for whatever purpose you may have).
What are the characteristic features of the progressor (steady state) portions of the curves? (Measured along the OOSsw crush front)

  • Tendency toward terminal velocity
  • A steady state acceleration of zero
That's the same thing in two different wordings.
What are the characteristic features of the initiator (initial movement to steady state) portions of the curves? (Measured along 2 points: roofline and crush front)

  • Crush front seems to start on floor 95
  • Quick take off velocity
  • Short transitory phase (reaches steady state velocity and acceleration rapidly)
That definition of "initiator" - do you use this consistently throughout your work?
Most people around here have a concept of a "collapse initiation phase" that begins with the first yielding piece of structure that starts an uninterupted chain of macro movement at the beginning of the final collapse, and ends roughly when something like your "fundamental conditions" as described above are fulfilled; in my words, when the vertical drop has progressed to a point where total collapse becomes inevitable.
This is (probably) a shorter time frame than your "initiator" here. Your initiator goes past the "point of no return" and through an additional phase where acceleration is > 0.

"Quick take off velocity" - really? I guess the whole thing takes off at V=0? Or do you mean that V(0) (from your fundamental condition above) has to be high? How high? By what criterion do you decide a take-off velocity is "high"?
Or do you mean high take-off acceleration, i.e. initial acceleration close to g?


I hope you find some questions helpful or at least legitimate.
 
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It's interesting to note how quiet M_T gets when the attention is put on him. Has he ever actually acknowledge criticism of his own work?

Personally, I don't think he really understands the purpose of the Bazant models. If he did, he wouldn't compare them in this thread (it would be off-topic).
 
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I post, but the posts are removed.

You know why.

Let's talk about ROOSD, shall we? You made a few suggestions on an actually mathematical actual approach to, actually, ROOSD, and I commented on them three posts up from here.

If you manage not to derail the topic once more (no excursions to Feynman; no more links and quotes from my, Oystein's, past opinions, etc.), I am confident they will stay and you may learn a bit about how to advance your mathematical approach to ROOSD!

I suggest you try to use mathematical and physical terms, including the word "mathematical", in their universally accepted meanings, then we can avoid unnecessary excursions on semantics and cut straight to the beef!

A word of encouragement: I am sure most posters here agree with you already that the mechanism you label "ROOSD" (in my possibly inapt shortcut: verloading of floors -> failure of floor-to-column connections -> progression! -> column failure mostly secondary) is largely the correct one; and that the various Bazant models are limited in their applicability to explain observed actual features of the actual WTC collapses. So why beat a horse that's already almost dead? Define your objectives and your metrics, explain your method and the desired level of detail, and we'll help you with the math!
 
I would take exception to the notion of connection failures as a key part of ROOSD. My sense is floor slab failures consist of several attributes where the slab load is no longer carried by the columns. The main attribute is fracturing of the slabs I would think not breaking of the connections to the columns. ROOSD is a flow a slabs in disintegrated form which destroys the slabs the descending mass fall upon.... think avalanche of concrete. The process also grinds the concrete back to sand and portland cement dust.
This would be in contrast with what was found in the aftermath. Connection failure is well documented.
 
This would be in contrast with what was found in the aftermath. Connection failure is well documented.

Of course in the aftermath after 400,000 tons of building collapse the connections would all have almost had to have failed. In fact there were only a few connections which were sound... on some core column I believe.

The ROOSD process was the crushing of the slabs not the connections.. which became a downward flowing fluid of densely packed concrete bits which from agitation ground themselves from large chunks to sand and powder sized debris. The frame came apart at the connections.. obviously...
 
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