Just so everyone knows, BV and BL are......
BV:
Mechanics of Progressive Collapse: Learning from World
Trade Center and Building Demolitions
Zdenfk P. Bažant, F.ASCE; and Mathieu Verdure
http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/466.pdf
BL:
Bazant & Le
Closure to "Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions"
http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/D25 WTC Discussions Replies.pdf
bio, I agree but the resultant debris could now be trapped within the intact perimeter structure. It could gather in the OOS regions by following the path of least resistance. This debris may be trapped between core and perimeter with no where to go but down through the OOS.
The paper suggests that continued OOS destruction may be a natural process, though it is yet to be tested mathematically. This process, though natural, is not a debunking of CD. From the CD point of view, it is a way to achieve complete CD by using minimal explosives.
Dave Rogers explained it well in his first post on page 1 when he said:
"I don't see anything contentious, either, about the statement that this mechanism does not prove that the collapse was unassisted by demolition devices; indeed, I suspect that no feature of collapse propagation could conceivably prove any such thing, because even a controlled demolition using explosives exhibits a natural collapse progression. It's collapse initiation that's the key differentiator in this instance."
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A good discussion of BV and BL is possible in view of the study presented in the OP, for there is much to say.
Unfortunately, I cannot do that here because most every poster who is defending BV has shown they have no capacity to distinguish between the argument in BZ and BV (only Dave has shown he may understand the difference). Consider the last post by Myriad. If that makes sense to you, I'm speechless.
I didn't realize that such a misunderstanding is so widespread among people who post here regularly. The barrier created by those who imagine that the BV argument is just a continuation of the BZ argument appears way too high to overcome, though discovering this barrier has been useful for me and, I hope, for you too.
If there are a few of you who can actually distinguish between the two arguments, please let me know and I can show you how BV and BL are proven wrong by the study.
Of not, the few readers that do understand the difference in the two arguments must be just as amazed as I am. Your comments can tell them much more about your own level of understanding than it does about the study.
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Just to verify, do you really believe the following comments are true?
R Mackey: "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."
You mean Bazant and Zhao.
Myriad: "Bazant's model is a limiting case representing the most favorable assumptions for collapse arrest."
Different papers, different arguments. That was pointed out a few times but he still seems to believe it is true.
David James: "It was written within a few days doesn't represent a full analysis, Why not critique the NIST report?"
Wrong paper. These are from 2007-2008 and still believed to this day.
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I asked: R Mackey seems to be saying he doesn't mean this to apply to WTC1 literally.
What do you think?
To which Dave answered:
"That's correct. 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."
That is the center of our disagreement. He actually does believe this literally, that crush down happens before crush up. This is pretty clear in the papers themselves (as long as you don't confuse their purpose and intent with BZ), but it became much clearer through long conversations with David Benson, who communicates with Dr Bazant.
You think I'm joking? I wish I was.
One of my favorite posters on another forum summed it up thus:
"I've said it before, it's worth saying again. I'm not at all confused where the model ends and reality begins, but I'm not so sure about the author. There is acknowledgement that the real affair was quite different in various ways, but then there's the insistence that significant early crush-up could not occur when it sure as hell looks like it did. Almost certainly did. I don't understand how that did not merit even a mention; perhaps he doesn't even know! It strongly suggests the author is wedded to theory such that the lines between theory and reality are blurred. Incredible intellect, without a doubt, wish I had a piece of that, but... It really becomes academic to the point of 'how many angels can dance on the head of a pin' - if there were angels, the argument might be worth double-checking!"
As stated in the (correct) papers in question, BV equs 12 and 17 are meant to be taken quite literally according to the author himself, as long as 4 simplifying assumptions are satisfied. Dr Bazant truly believes his 1-D model can be used to to measure the actual trajectory of the crush front for WTC1 and that the 4 simplifying assumptions apply to WTC1, including a slight lean.
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One of the few readers that understands what I am saying may ask: Major_Tom, why do you bother trying to explain something that most of these guys will never understand?
Now
that is a good question. People from other forums are following this discussion, people who have shown the capacity to follow the argument. This discussion may help them clarify what the most common misconceptions are within the Bazant papers. By seeing common mistakes repeated, people can get a better sense of where the "debate" stands at present.
