Merged Applicability of Bazant's model to the real world
- Thread starter pgimeno
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alienentity
Illuminator
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I previously did quite clearly state that the upper block of tower 2 seems fairly intact until it disappears into the dust.
That argues in Bazant's favour - that is, it seems to support the crush-down, crush-up mathematics fairly well. You may disagree, but that's what I see. I repeat it because you've perhaps missed the first time I stated that opinion.
Second, I believe that the rubble zone hypothesis is valid even when you have a chaotic meeting of structure, as I also believe happened. I further think that the hypothesis is even more applicable with the spearing and breaking of floor systems, as opposed to unlikely column-on-column collisions.
Why? Because the creation of rubble (that is, chunks, fragments etc) is even more likely in that case, and that rubble then impacts with greater and greater energy on the structure below. It only takes a short amount of collapse (I haven't bothered to try to calculate exactly, it would be a rough estimate anyway) to get this process up and running, and crush down all the way to the ground.
I don't expect that the process was cartoon-perfect. The hypothesis is not meant to be a literal model of the collapse. For that, you'd need to run a full simulation and see what happens.
I think a full model would be very interesting and would answer a lot of these questions well.
ROOSD makes sense, I think it has merit, but I'd prefer to see it published in an engineering journal, as I said previously. I may be able to understand some engineering, but I'm not an engineer and I'm not qualified to judge which is the best explanation. That's the best i can do.
Birds of a feather? What was it Forrest G. said?
Perhaps David Benson could be convinced to run it through his local implementation. He's a member of the911forum.
ozeco41
Philosopher
My only reason for raising the possibility is that there does not seem to be anything currently in the middle ground between what really happened at WTC on 9/11 and the theoretical 'homogeneous blocks' model of BV.
So I suggested the 'pseudo weak columns' concept as a way of rigorously representing what really happened at WTC in a way which would also fall within the scope of BV. There may be others but I don't see anyone trying to rigorously do the 'fit'.
It could be a legitimate 'bridge' between what otherwise are two distinct and incompatible situations - I remain convinced that the two are incompatible AND that no explanation I have seen so far about 'modelling simplifications' provides a legitimate bridge between or umbrella over the two.
I think the ROOSD study references my outline asynchronous impact model (which uses floor connection strength as the propogation barrier) and a tweaked copy of my synchronous step-wise spreadsheet model with all parameters set to ignore everything bar flooring mass and connections. Neither fit the bill there, but the latter is functional for experimentation if you wanted to give it a whirl.
As I have said if you eliminate the vitriol and stick to discussing your topic you will reduce what comes back. For example, these lines:
and especially the hi-lighted parts lean far more to baiting (not to mention it is saying the same thing over and over again) and in such a polarized atmosphere you set yourself up for emotional responses. I know it is hard to deal with people writing your work of but you add to your frustration playing the tit for tat.
Personally, no matter which forum I am on (and I belong to a number of non-9/11 forums) people who talk with great authority and whom believe very soundly in what they are saying make me wary. Again it gives me the vibe that it may not even be worth my while to discuss their work with them. I do like to ask questions but hate to be insulted or jumped on for asking them.
Yes, and in the paper, just as I repeatedly pointed you. Again, BLGB page 902 (11 in the PDF). And if you are a good observer, you will note that it's not comparing the crush direction of his model with the real crush direction. Which makes the criticism about crush direction moot. Come on, guys, you can't be that thick.
Oh, are you saying that there are features predicted by the model that don't match the real world?
NOW you are really dealing with the subject of the thread! Can you elaborate on that?
Key words highlighted. Alas, no reference to the real crush direction. Try again.
Bump for MT, as he is insisting on the same stuff again without addressing these objections.
(From http://www.internationalskeptics.com/forums/showthread.php?p=6795905#post6795905)
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It has been put to test with respect to the speed of fall of the WTC towers (again, see p.902 of BLGB).
But a model is a mathematical tool, which, like many other mathematical tools, you don't really know when it can become useful, but if it's there, you can use it.
You don't have a model that can be used by the engineering community to be applied to other buildings to extract conclusions out of them. And not only because of your refusal to publish your work. You merely have a description of an event, not a model to which input parameters can be applied and output parameters extracted.
A model is what BV attempts to do. To me, BLGB is a sample application of that model to the case of the WTC towers. The graph femr2 has shown is an application of the model to the WTC parameters, not a comparison with the real features. And you keep doing the same all the time.
Engineering models are not there to solve conspiracy puzzles. You seem to assume that as the purpose, and that's where you are failing again and again.
If you made refinements, fine, but it's not "your" description of the collapse. Give credit where credit is due.
And it's not the topic of this thread either.
(From http://www.internationalskeptics.com/forums/showthread.php?p=6795905#post6795905)
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Well, I don't follow any engineering journal, but I'd say it's still too early to determine its validity and outreach, because it hasn't been put to test enough times.
It has been put to test with respect to the speed of fall of the WTC towers (again, see p.902 of BLGB).
But a model is a mathematical tool, which, like many other mathematical tools, you don't really know when it can become useful, but if it's there, you can use it.
You don't have a better one.
You don't have a model that can be used by the engineering community to be applied to other buildings to extract conclusions out of them. And not only because of your refusal to publish your work. You merely have a description of an event, not a model to which input parameters can be applied and output parameters extracted.
A model is what BV attempts to do. To me, BLGB is a sample application of that model to the case of the WTC towers. The graph femr2 has shown is an application of the model to the WTC parameters, not a comparison with the real features. And you keep doing the same all the time.
Engineering models are not there to solve conspiracy puzzles. You seem to assume that as the purpose, and that's where you are failing again and again.
FEMA already did that before you.
2.2.1.5 Progression of Collapse
Construction of WTC 1 resulted in the storage of more than 4x1011 joules of potential energy over the 1,368-foot height of the structure. Of this, approximately 8x109 joules of potential energy were stored in the upper part of the structure, above the impact floors, relative to the lowest point of impact. Once collapse initiated, much of this potential energy was rapidly converted into kinetic energy. As the large mass of the collapsing floors above accelerated and impacted on the floors below, it caused an immediate progressive series of floor failures, punching each in turn onto the floor below, accelerating as the sequence progressed. As the floors collapsed, this left tall freestanding portions of the exterior wall and possibly central core columns. As the unsupported height of these freestanding exterior wall elements increased, they buckled at the bolted column splice connections, and also collapsed. Perimeter walls of the building seem to have peeled off and fallen directly away from the building face, while portions of the core fell in a somewhat random manner. The perimeter walls broke apart at the bolted connections, allowing individual prefabricated units that formed the wall or, in some cases, large assemblies of these units to fall to the street and onto neighboring buildings below.
(FEMA 403, chapter 2, p. 2-27)Construction of WTC 1 resulted in the storage of more than 4x1011 joules of potential energy over the 1,368-foot height of the structure. Of this, approximately 8x109 joules of potential energy were stored in the upper part of the structure, above the impact floors, relative to the lowest point of impact. Once collapse initiated, much of this potential energy was rapidly converted into kinetic energy. As the large mass of the collapsing floors above accelerated and impacted on the floors below, it caused an immediate progressive series of floor failures, punching each in turn onto the floor below, accelerating as the sequence progressed. As the floors collapsed, this left tall freestanding portions of the exterior wall and possibly central core columns. As the unsupported height of these freestanding exterior wall elements increased, they buckled at the bolted column splice connections, and also collapsed. Perimeter walls of the building seem to have peeled off and fallen directly away from the building face, while portions of the core fell in a somewhat random manner. The perimeter walls broke apart at the bolted connections, allowing individual prefabricated units that formed the wall or, in some cases, large assemblies of these units to fall to the street and onto neighboring buildings below.
If you made refinements, fine, but it's not "your" description of the collapse. Give credit where credit is due.
And it's not the topic of this thread either.
A quite lengthy quote I'm afraid, but necessary...
The author is indicating that if the column cross sections changed discontinuously right below or right above the first collapsed stor(e)y, the initial crush-up distance would be affected.
The author is also indicating, and there is no other way to interpret, that this (cross-section change) does not appear to be the case in the real tower.
The author is stating that because, in the real tower, column cross-sections don't change (as much as the author thinks they would need to) that crush direction calculations are therefore justified.
He's not talking about *some generic building*. He's talking about WTC1/2.
Yes, I'm aware your wording is specific.
However, the author is misapplying calculated crush direction metrics to the real building, and using building measurements as justification for his results.
The author is a bit lost. The lines between fiction and reality have become very blurred for him.
You and I can argue about the semantics ad infinitum, but the bottom line is for others to be fully aware of how immersed and convoluted the author has become, failing to see how blurred his viewpoint is and how messed-up an interpretation of what he's saying a reader could take from his wanderings.
Easy to read, huh ?
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The author applying crush direction features of the model to the real world is also on-topic.
Of course not. He's comparing yet another model metric to the real world, concluding that the crush-down duration matches interpretation of the seismic record.
In other words that the descent time of the model, which is based upon a mode of destruction which is as far from matching reality as possible (by definition), is correct as it matches the seismic record.
Convoluted nonsense.
Try again ? What ?
The author is misapplying the model to the real world.
Have you tried implementing the bazant et al model(s) in any form ?
I suggest you give it a whirl if not, and test it with the lower floor strength only scenario suggested by Ozeco41.
Er...
BLGB...
Seems the authors of BLGB are not entirely in agreement with you.
Have you actually read it ?
DGM
Skeptic not Atheist
I think you missed his distinction between model (BV) and application of the model (BLGB).
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Nope. I think you missed the actual point of the quote you are using, which relates to the fact that BLGB is significantly focussed upon 'conspiracy puzzles', in contradiction to the claim...
I agree in essence that, in general, engineering models are not there to solve conspiracy puzzles, but the authors of the paper (and model) don't seem to be of entirely the same opinion, or they wouldn't attempt to use it so.
DGM
Skeptic not Atheist
But his distinction was BLGB is not a model(it's an application), BV is the model. I'm sure you know the difference.
It contains extension and use/application of a model to be slightly more precise.
The thread is focussed upon clarifying correct application of the model(s) to the real world.
If you choose to split particularly thin hairs about semantics, that's your own lookout.
As I said in the post you just quoted...
I agree in essence that, in general, engineering models are not there to solve conspiracy puzzles, but the authors of the paper (and model) don't seem to be of entirely the same opinion, or they wouldn't attempt to use it so.
DGM
Skeptic not Atheist
I was just pointing out a distinction (qualifier) that he made and you missed. No skin off my back.
Again, as I said, no, it was not missed.
Lovely. Rather a waste of your time (and mine) it seems, bearing in mind your initial assertion was wrong.No skin off my back.
Ho hum. As it's no skin off your back I'll consider you prepared to accept being corrected (for the second time) and move on
An embarrassingly deperate effort to save face:
DMG post 1474: "I think you missed his distinction between model (BV) and application of the model (BLGB). "
Now, people who could not even distinguish between BZ and BV just a few pages ago can distinguish between a model in BV and it's application to WTC1 and 2 in BL and BLGB.
In BL and BLGB, Bazant talks about WTC1 and 2. In the BV closure (called BL) he is answering questions by 2 "twoofers". There is no reverence to some generic model, only to two specific buildings, the ones the "twoofers" claim wes demoed.
BLGB is titled "What Did and Did not Cause Collapse of WTC Twin Towers in New York", and it's sole topic is, not surprisingly, the WTC towers.
In the conclusion he claims his model can explain 8 different features of the collapses. He explicitly states that his model is capable of matching all observations, including 8 specific features.
>>>>>>>>>>
There are two last mindless attempts to salvage these papers, one expressed by Pgimeno and the other by Myriad.
Myriad clings to the belief that the extreme single collision discussed in BZ is carried over to the BV propagation model, hence the mutant JREF invention called "progressive collapse of the scenario which most favors collapse arrest". THis is a desperate attempt to salvage the model by stressing it is only an extreme case most favorable to survival.
It makes no sense but sense has nothing to do with it. This is clinging, not reason.
The other by Pgimeno in which the series of papers are claimed to represent some abstract model of generic buildings, the WTC towers being only one of many applications. Even though Bazant writes of nothing other than the WTC towers in both the BV closure (BL) and even though in BLGB Bazant claims his model matches all observations of WTC1 and 2, the sole topic of that paper, this is glossed over in a last desperate attempt to salvage the model by stressing it's generic nature.
DMG post 1474: "I think you missed his distinction between model (BV) and application of the model (BLGB). "
Now, people who could not even distinguish between BZ and BV just a few pages ago can distinguish between a model in BV and it's application to WTC1 and 2 in BL and BLGB.
In BL and BLGB, Bazant talks about WTC1 and 2. In the BV closure (called BL) he is answering questions by 2 "twoofers". There is no reverence to some generic model, only to two specific buildings, the ones the "twoofers" claim wes demoed.
BLGB is titled "What Did and Did not Cause Collapse of WTC Twin Towers in New York", and it's sole topic is, not surprisingly, the WTC towers.
In the conclusion he claims his model can explain 8 different features of the collapses. He explicitly states that his model is capable of matching all observations, including 8 specific features.
>>>>>>>>>>
There are two last mindless attempts to salvage these papers, one expressed by Pgimeno and the other by Myriad.
Myriad clings to the belief that the extreme single collision discussed in BZ is carried over to the BV propagation model, hence the mutant JREF invention called "progressive collapse of the scenario which most favors collapse arrest". THis is a desperate attempt to salvage the model by stressing it is only an extreme case most favorable to survival.
It makes no sense but sense has nothing to do with it. This is clinging, not reason.
The other by Pgimeno in which the series of papers are claimed to represent some abstract model of generic buildings, the WTC towers being only one of many applications. Even though Bazant writes of nothing other than the WTC towers in both the BV closure (BL) and even though in BLGB Bazant claims his model matches all observations of WTC1 and 2, the sole topic of that paper, this is glossed over in a last desperate attempt to salvage the model by stressing it's generic nature.
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