Bazant in a nutshell

[beachnut]

The actual collapse mechanism is the only lens through which the collapses or the question of CD can be approached.

...

?
Nonsense. What a load of junk. Show your math next time, and you might fool a few people with BS.

The task is to explain why the dam broke, you are fixated on explaining how the flood progressed. Please take some engineering courses.

 

[Oystein]

Alright then,

ozeco says (in a nutshell): BV, BLGB, and BL have no discernible objective - at least none that's useful for us here who are trying to convince truthers there was no CD (nor for truthers who wish to do the opposite) (nor for anybody with forensic interest who wishes to understand the actual collapse of the WTC towers).

I am now curious if anyone (still looking at tfk, W.D.C, ...) disagrees with this assessment.




As for your (ozeco's) doubts about the 1-story-freefall assumption of B/BZ:
It was a starting assumption; somewhat arbitrary, perhaps, but calculation showed that the kinetic energy imparted by freefall through one story (actually: a velocity that is equal to that achieved by 1-story freefall - doesn't literally have to be 1-story freefall...) is greater than what the structure could absorb per story by a factor of more than 8. I.o.w., freefall over 1/8 of a story would have the same effect, or 1/2 g over 1/4 story (probably the problem is not fully linear, but you get the drift).

AND I think this discrete concept of a freefall phase, then a crash/buckle/crush phase, then the next freefall phase, can be generalized to allow for multiple local nstances of such phases overlapping - provided that on average mass has a chance to fall at least about 1/8 of a story per story.

Anyway, I personally have found B/BZ to be pretty helpful towards understanding why total collapse progression is inevitable - it is applicable to both theoretical ideals and a lot of dirty less than ideal reality. And this, I claim, was the objective he had, and achieved.

Now I wonder if anyone disagrees with THAT statement

 

[ozeco41]

Alright then,

ozeco says (in a nutshell): BV, BLGB, and BL have no discernible objective - at least none that's useful for us here who are trying to convince truthers there was no CD (nor for truthers who wish to do the opposite) (nor for anybody with forensic interest who wishes to understand the actual collapse of the WTC towers)....

Since the only bit which relates to what happened to WTC is the proof that the energy was more than needed for collapse progression it is only relevant to proof of no CD for collapse progression. It says nothing about CD in collapse initiation. And the "disproof" of CD in progression does not need Bazant's help. Bazant is of no help other than in the sense of "There was even more energy than was needed so, even though the progression occurred by a far easier mechanism than Bazant allows for, it still happened". Logically that adds no value if you have access to my or Major_Toms explanations or equivalent from other persons including working through the mechanism yourself. It can be as simple as "It would have collapsed even if the columns were in place but they weren't and the floor connectors were a lot weaker." (And I have left two complicating factors out so don't take that as anything more than a simplified example of the "style" of argument.

....I am now curious if anyone (still looking at tfk, W.D.C, ...) disagrees with this assessment....

I'm not losing sleep waiting.... and I'm a big boy and I won't sulk too much if someone disagrees with me and provides persuasive reasoning.

...As for your (ozeco's) doubts about the 1-story-freefall assumption of B/BZ:
It was a starting assumption; somewhat arbitrary, perhaps, but calculation showed that the kinetic energy imparted by freefall through one story (actually: a velocity that is equal to that achieved by 1-story freefall - doesn't literally have to be 1-story freefall...) is greater than what the structure could absorb per story by a factor of more than 8. I.o.w., freefall over 1/8 of a story would have the same effect, or 1/2 g over 1/4 story (probably the problem is not fully linear, but you get the drift)....

Which is of no relevance to my doubts either for or against.

...AND I think this discrete concept of a freefall phase, then a crash/buckle/crush phase, then the next freefall phase, can be generalized to allow for multiple local nstances of such phases overlapping - provided that on average mass has a chance to fall at least about 1/8 of a story per story...

Take care you dont lose the plot. If you are discussing an arbitrary building you could well be correct. BUT if you are discussing WTC reality it does not fit. The assumptions of a "...a freefall phase, then a crash/buckle/crush phase, then the next freefall phase..." do not apply to what really happened at WTC so there is no basis for those concepts to "..be generalized..."

...Anyway, I personally have found B/BZ to be pretty helpful towards understanding why total collapse progression is inevitable...

Me too but don't take it too far is my warning.

...it is applicable to both theoretical ideals and a lot of dirty less than ideal reality. And this, I claim, was the objective he had, and achieved.

Now I wonder if anyone disagrees with THAT statement

I disagree in part so let me try to be very specific as to where I disagree.

I think you are risking people thinking that you are glossing over and conflating things which I kept very separate and distinct. So let me make the provisos very explicit:
1) "Anyway, I personally have found B/BZ to be pretty helpful towards understanding why total collapse progression is inevitable" Me too BUT it applies only to collapse progression where the reality is easy to see without benefit of Bazant's energy calculations. Where knowing Bazant was right because the easy to see mechanism says Bazant was right is more intuitive than the reverse sequence of understanding collapse progression because Bazant said there was more than enough energy. The "more than enough" is obvious without Bazant in there muddying the waters. Says me the engineer anyway. I can refer to my "words without maths" explanations if needed.....and if I can find some.

2a) " it is applicable to both theoretical ideals" which is a non-statement implied strawman - I didn't say there was anything wrong with it in the theoretical model.

2b) "...and [it is applicable to] a lot of dirty less than ideal reality" - it isn't applicable other than in the narrow focus of collapse progression as I have both stated and clarified previously. Your wording is foggy/ambiguous and could seem to imply more than you mean PLUS I'm not sure what you mean.

 

[W.D.Clinger]

Alright then,

ozeco says (in a nutshell): BV, BLGB, and BL have no discernible objective - at least none that's useful for us here who are trying to convince truthers there was no CD (nor for truthers who wish to do the opposite) (nor for anybody with forensic interest who wishes to understand the actual collapse of the WTC towers).

I am now curious if anyone (still looking at tfk, W.D.C, ...) disagrees with this assessment.

I believe this is your first reference to me within this thread.

The most important thing I have to say, by far, is that these questions lie pretty far outside my competence.

Because of that, I cannot disagree with the above assessment (in the sense of being ready to present a solid argument against it), but I'd like to emphasize that I do not agree with the above assessment either (in the sense of being ready to present a solid argument for it).

What I can do and have done is to spot-check the math. On my first reading of BV, I found an obvious math error in one of their numbered equations, which led me to find about half a dozen related errors when I read the paper more closely. It turned out that none of those errors were significant, but they reduced my confidence in the quality of the paper and in its peer review process. I'm not inclined to assume the authors got everything right.

That said, I think most of the criticisms that have been levelled in this subforum against their crush-up/crush-down calculations have come from people who understand neither the physics nor the math. So far as I can tell, which isn't very far, that aspect of their papers may be largely correct for their model. As ozeco41 and others have said, however, their model may apply to the WTC collapses in only the most general of terms, if indeed at all. I am not competent to express an opinion on that.

If I sound evasive, it's because I think it would be more dangerous to give credence to the opinions of largely unqualified people such as myself than to recognize that our opinions don't count for much.

Anyway, I personally have found B/BZ to be pretty helpful towards understanding why total collapse progression is inevitable - it is applicable to both theoretical ideals and a lot of dirty less than ideal reality. And this, I claim, was the objective he had, and achieved.

Now I wonder if anyone disagrees with THAT statement

Once again, I don't exactly disagree with that statement, but I don't exactly agree with it either.

I personally have found all of these papers somewhat harder to read than I would have expected. Most of that difficulty is attributable to the fact that I am not an engineer, but I think part of it has to do with how the papers were written.

 

[ozeco41]

... So far as I can tell, which isn't very far, that aspect of their papers may be largely correct for their model...

For what it may be worth I think their crushdown/up concept is valid for their model BUT their model is very different to WTC.

... As ozeco41 and others have said, however, their model may apply to the WTC collapses in only the most general of terms, if indeed at all...

My objection is not resolved by "generalising" - I have a specific limitation in mind - so Bazant's concepts apply fully one side of the divide and apply not at all once the boundary of validity is passed. Sorry but I cannot express it more clearly at this time.

... I personally have found all of these papers somewhat harder to read than I would have expected. Most of that difficulty is attributable to the fact that I am not an engineer, but I think part of it has to do with how the papers were written.

I found them very hard to read from my preferred perspective looking for the boundaries of their logic and any gross errors therein. I blame the deliberate obscurantist style of academic writing PLUS the lack of a clear statement of the assumptions and underlying model they are proposing. And it is in both those areas where I disagree. Given those areas of disagreement I never bothered checking the maths - I would not be confident in my own rusty maths at this stage of my life.

 

[Oystein]

...
2b) "...and [it is applicable to] a lot of dirty less than ideal reality" - it isn't applicable other than in the narrow focus of collapse progression as I have both stated and clarified previously. Your wording is foggy/ambiguous and could seem to imply more than you mean PLUS I'm not sure what you mean.

Yes, of course, collapse progression, which isn't a narrow focus at all in my mind. I am quite clear that B/BZ doesn't contain any proof about initiation; they offer a descriptive explanation, but with no math, so don't worry, I am not looking at that part.

 

[Oystein]

...
That said, I think most of the criticisms that have been levelled in this subforum against their crush-up/crush-down calculations have come from people who understand neither the physics nor the math. ...

... NOR, I presume, the relevance.

Thanks for replying, rest of your opinion gratefully noted.

 

[ozeco41]

Yes, of course, collapse progression, which isn't a narrow focus at all in my mind....

No problem to change "narrow" to "specific" if that solves your bit of concern.

So it becomes:

...2b) [...] it isn't applicable other than in the specific focus of collapse progression as I have both stated and clarified previously. ...

...or am I chasing unimportant details???

 

[Oystein]

Not unimportant, just uncontroversial, I think

 

[beachnut]

I... That said, I think most of the criticisms that have been levelled in this subforum against their crush-up/crush-down calculations have come from people who understand neither the physics nor the math. ...

BINGO
Someone wrote a "book" confirming this observation.

 

[cmckay]

I'm bumping this just for some clarification on something.

My understanding is that Bazant's paper was published just 2 days after 9/11.
If so, how did it get through the whole peer-review process in only 2 days? Surely it takes a helluva lot longer than that.

 

[ozeco41]

I'm bumping this just for some clarification on something.

My understanding is that Bazant's paper was published just 2 days after 9/11.
If so, how did it get through the whole peer-review process in only 2 days? Surely it takes a helluva lot longer than that.

He put out the "quick and dirty" version two days after the event - then followed up with more rigorous versions over the following months.

His "quick and dirty" version was correct on the key points - surplus of available energy within a play safe limit case^#.

Since his initial claim was correct within his assumptions most of us, me included, have no problem with the "post hoc hindsight" timing of the formalities.





# (One of his assumptions was not "play safe" - see my earlier comments. I've never pushed that point on this forum - lèse majesté is still a capital offence here and I didn't want to rile the Bazantophiles.. )

 

[cmckay]

Ah, I see.

I just noticed his paper in the Journal of Engineering Mechanics reads "January 2002" in the corner. I initially thought THAT paper came out 2 days after the event.

Makes sense now.

 

[ergo]

Makes sense now.

Does it? Why?

Here is the paper.

Why was an energy analysis and hypothetical collapse explanation needed two days after the event?

 

[cmckay]

Does it? Why?

Here is the paper.

Why was an energy analysis and hypothetical collapse explanation needed two days after the event?

When one of the largest buildings in the world collapses, I'm sure the engineering community is going to be very interested in why it collapsed.

Besides, what point are you trying to make with your question? Do you think Bazant was a government stooge?

 

[kid meatball]

Does it? Why?

Here is the paper.

Why was an energy analysis and hypothetical collapse explanation needed two days after the event?

Because people like you and I were very confused and wanted answers, quickly.

 

[ergo]

When one of the largest buildings in the world collapses, I'm sure the engineering community is going to be very interested in why it collapsed.

Two of the tallest buildings in the world collapsed. And I agree. I think most structural engineers did not anticipate a collapse. But why the rush to explain it before a standard investigation could take place? Why would Bazant assume he knows more than structural engineers?

Not only did he get it so terribly wrong, but he was in such a hurry to try to explain it all away. No one was asking him. Why not wait for appropriate expertise?

 

[ergo]

Because people like you and I were very confused and wanted answers, quickly.

That's a very good answer.

 

[beachnut]

Two of the tallest buildings in the world collapsed. And I agree. I think most structural engineers did not anticipate a collapse. But why the rush to explain it before a standard investigation could take place? Why would Bazant assume he knows more than structural engineers?

Not only did he get it so terribly wrong, but he was in such a hurry to try to explain it all away. No one was asking him. Why not wait for appropriate expertise?

The chief structural engineer for the WTC knows why it collapsed; impacts and fire. 911 truth has no clue.

911 truth can't understand Bazant; 911 truth does not do differential equations; that is called math, 911 truth and math don't mix.

Bazant can do a paper in two days, because he can do math - 911 truth can't figure out the collapse given the answers and 11 years. Kind of self-critiquing.

 

[DGM]

Why would Bazant assume he knows more than structural engineers?

What makes you think he does? BTW, he is one.

Not only did he get it so terribly wrong, but he was in such a hurry to try to explain it all away. No one was asking him. Why not wait for appropriate expertise?

You've never read his paper. I can tell from this comment.

What part of his paper was out of his field of expertise?