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OOS Collapse Propagation Model

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Major_Tom said:
..... snip

We need to clear up all the bad information concerning what the Bazant papers prove and what they do not prove. To clear things up I will offer a short review of each paper beginning with Bazant and Zhou.

My Review of Bazant and Zhou (first draft) is here:
http://www.the911forum.freeforums.org/review-of-bazant-and-zhou-t375.html .......

.
Click to expand...

............................................
I prefer a similar but alternate description of the stages as:

stage 1) Airplane damage, fuel and fires

stage 2) Visible deformations leading into initial buckling sequence, especially inward bowing (IB) of the south face.

stage 3) Initial buckling sequence (initial lateral propagation of column failure and trajectory over the first 12 ft.

stage 4) Initial collision and resulting trajectory and behavior through subsequent collisions

stage 5) Runaway collapse propagation (ROOSD)


BZ skips over the initial buckling sequence (stages 2 and 3), providing only a simple narrative of his opinion presented as fact. The paper actually focuses on the first collisions only, or stage 4.

Concerning stages 2 and 3, Dr Bazant offers nothing but a narrative. He narrates, or "talks" through the initial buckling sequence and this narration constitutes proof of nothing. It is just his opinion of what may have happened.

Bazant offers mathematical analysis for stage 4 only, the first collision, asking: If the top part falls for 12 feet and smashes into the bottom part, even if it makes a perfect landing can the columns elastic spring energy make the building bounce like a ball? and concludes it wouldn't. That's all.
Click to expand...
You don’t understand the big picture.

1) First phase of Towers 1,2 global collapse is the damage and gradual failure of the critical floor. This initial failure is what NIST exhaustively studied and provided a gravity alone explanation.

2) Second Phase of Towers 1,2 is the progressive collapse of the remainder of the structure to grade following the initial failure of the critical floor. Bazant mathematically describes this gravity alone global progressive collapse following the initial failure of the critical floor.

These two phases are complementary and universally understood to be such by the qualified peer reviewed civil/structural engineering universe and their published studies. These engineers all agree in a gravity only explanation for both phases.

You have to choose in which phase your fictitious explosives caused failures that cannot be explained by gravity alone.
 
Major_Tom said:
How can we look for evidence unless we know where to look? How can you talk of sizing devices if you know nothing about the most probable targets?
Click to expand...


Ever hear of a "gedanken (thought) experiment"?

We can get dimensions of the smallest structural elements used at WTC and then get any one of the demolition handbooks. A handbook tells you quantity and placement of charges needed to cut a beam. Do the math.

I like the U.S. Army's FM 5-250 Explosives & Demolitions Handbook.

Calculate how many pounds (or cubic feet) of high explosive it takes to cut one small beam. Describe how you are going to place the charges as described in the handbook. Tell us what your results are.

Since all your assumptions err on the low side, a real demolition plan would be much bigger.

Someone may help calculate the sound levels generated by that quantity.

http://en.wikipedia.org/wiki/Thought_experiment
 
Major_Tom said:
If we do not clear away all the BS we will never be able to address the real issues concerning the possibility of CD.
Click to expand...
,
You mean, the real issues such as the complete lack of the kind of sequenced explosions required to do a CD?
,
 
BasqueArch said:
You don’t understand the big picture.

1) First phase of Towers 1,2 global collapse is the damage and gradual failure of the critical floor. This initial failure is what NIST exhaustively studied and provided a gravity alone explanation.

2) Second Phase of Towers 1,2 is the progressive collapse of the remainder of the structure to grade following the initial failure of the critical floor. Bazant mathematically describes this gravity alone global progressive collapse following the initial failure of the critical floor.

These two phases are complementary and universally understood to be such by the qualified peer reviewed civil/structural engineering universe and their published studies. These engineers all agree in a gravity only explanation for both phases.

You have to choose in which phase your fictitious explosives caused failures that cannot be explained by gravity alone.
Click to expand...

You don't understand the purpose of the clarification. Earlier in this thread, it was claimed that Bazant's papers prove there was no controlled demolition. Since that derail, much time has been spent discussing collapse initiation at the expense of the topic of the thread, which is "OOS Collapse Propagation Model".
 
BigAl said:
We can get dimensions of the smallest structural elements used at WTC and then get any one of the demolition handbooks. A handbook tells you quantity and placement of charges needed to cut a beam. Do the math.
Click to expand...

Before comparing dimensions, you could avoid redundancy by working out which structural elements would collapse anyway, without being the target of a device.
 
bardamu said:
Before comparing dimensions, you could avoid redundancy by working out which structural elements would collapse anyway, without being the target of a device.
Click to expand...

I think you missed the point.
 
femr2 said:
ROFL. I know it was you. You know it was you. Everyone else can believe whatever they choose to. blah blah blah
Click to expand...

Like your position on 9/11..it is derived through a lack of education, and you present zero evidence to support or bolster it.

Fact is:


1)You have presented zero proof I am some one with the 'super uber-cool' screen name of "BigC"
2)I am not "BigC"
3)I never was "BigC"
4)You presented an argument between you and BigC
5)You said the conversation was "1 day ago"
6)Then you backed off and said it occured "11 months ago"
7)Then reverted back to "it was yesterday"
8)You presented this argument to prove you were versed in basic physics
9)You got the answer to that physics question wrong.

I never claimed to be a physics expert, did I? You did. In fact, you did, and not only failed to correctly answer the simple question I asked of you, then claimed it was correct, then pretended you never answered it the way you did, then tried to back in another incorrect answer, then avoided all subsequent questions...

But

You just answered the very question that was asked of you by BigC incorrect and tried to present that as evidence that you answered the question that I asked you correctly.

How does this make sense?

If I were, as you are, an uneducated Charlatan twoofer, then I would conclude you are jammonious because you both present evidence that proves your point to be wrong while trying to solidify your point.

I can not make it any clearer than that.
 
Big Al, Carlitos asked the same thing about decibel levels and sizing explosives.

He asked: "Please calculate the minimal explosives required, including their likely decibel levels. "

I answered: "Wouldn't you need to know the probable targets first? Let's say we both agree the probable targets would be core columns. How can you even attempt an estimate if you cannot answer the following questions:

1) Were the core columns (CC) around the 98th floor box columns or H beams?
2) Each column section is about 36 ft long, spanning 3 floors. How were the columns connected to each other at that elevation? Were they welded, bolted or both?
3) Were the CC to CC connections for adjacent columns staggered relative to each other, or are the CC to CC connections for all 47 CCs at the exact same elevations?
4) If the connections for all 47 CCs were at the exact same elevations, on which floors are they located around the collapse initiation area.

I'm sure you will agree that blowing the weld of a box column is much louder than doing so for a H beam."
>>>>>>>>>>>>>>>>>>>>>>

Big Al, have you ruled out the use of explosives during collapse initiation and early deformation? How can you do it if you cannot answer the simple structural questions posed above?

I also wrote to Carlitos:

"I know how to answer each of those questions, but I'd like to see you or others from this forum do it first. Some of you may claim to have looked into the matter previously and have ruled out CD based on your research. If you or others here cannot answer them, please let me know by indicating clearly that you do not know the answers.

I won't do your research for you. You claim to have studied the subject before arriving at a conclusion. R Mackey claims to rule out CD by diligent application of the scientific method.

Please tell me the nature and location of the CC connections around the 98th floor, the most likely target of an attack. They are hard questions so I don't judge anyone who cannot answer them. But if you cannot answer them, I doubt if you've seriously looked into the question at all."

If you and R Mackey and NB answer these basic structural questions, we can consider what is necessary to do the job. If you cannot, please just admit it, and I'll give you the answers.

But if you cannot answer them or never really thought about them at all, how can you or anyone claim to have applied the "scientific method" to rule out explosives?

Big Al asks: "A handbook tells you quantity and placement of charges needed to cut a beam." Why would you cut a beam? Why not focus on the weakest part (the CC to CC connections).

Do your own work.
 
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Carll68, please show us you skills in physics and reading comprehension to answer the following questions, which actually are on topic in this thread:


A summary of my questions concerning the Bazant papers asked thus far:


1) In BL, can you explain why Dr Bazant insists that crush down must be complete before crush up occurs. Does he mean this literally?

2) Do you consider the equations of motion in BV, equations 12 and 17, to be accurate for WTC1 considering the information in the ROOSD study?

3) Does Dr Bazant believe crush down, then crush up applies literally to WTC1? (or as just a "limiting hypothetical case in which the structure is best able to resist collapse")

4) Are the findings in the OOS study consistent with the claims of crush down preceding crush up in BV and BL?

5) Where in the BLGB arguments is the possibility of a CD based on ROOSD, exploiting the natural weaknesses of the building with minimal explosives, addressed?

If it is not, is it not true that the the arguments in BLGB are largely irrelevant when considering this type of controlled demolition?

6) When Bazant makes the following statement in BL, what does he mean?:

"So it must be concluded that the simplifying hypothesis of
one-way crushing (i.e., of absence of simultaneous crush-up),
made in the original paper, was perfectly justified and caused
only an imperceptible difference in the results. The crush-up
simultaneous with the crush down is found to have advanced
into the overlying story by only 37 mm for the North Tower
and 26 mm for the South Tower. This means that the initial
crush-up phase terminates when the axial displacement of
columns is only about 10 times larger than their maximum
elastic deformation. Hence, simplifying the analysis by neglecting
the initial two-way crushing phase was correct and
accurate."

Is he applying this to WTC1, or to just a hypothetical extreme case?
>>>>>>>>>>>>>>>>>>>>>>>

These questions were carefully chosen to expose fundamental weaknesses in Dr Bazant's papers. They also can help us understand the papers better. This is important because there are many false beliefs about what the papers say and do not say.

I do not expect most of you to be able to answer these questions, though if you claim to understand the papers you really ought to be able to answer them by citing quotes from the (correct) papers. Instead we'll go through the questions together and look for the answers using direct quotations of Dr Bazant's own words.

What we have seen in the first 5 pages of this thread is there are many misconceptions about the papers. In the future, an astute reader may want to ask those provide interpretations of what Dr Bazant "felt" or "intended" in the papers to back up their opinions with actual quotes from the (correct) papers. If they cannot, you should be very wary about what and who to "believe".
.......................

Carll68, please use your vast education to try to answer these basic questions about Bazant's papers. This way you can stay on topic and show femr your physics skills.
 
Major Tom....please point out where I said I was an expert in physics.

Then, please proceed to present your peer reviewed scientific evidence of a "CD" present at either WTC 1,2 or 7.

This should be a snap for you, right Major Tom?

Thanks in advance.

Carll68
 
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Basquearch writes:

"You don’t understand the big picture.

1) First phase of Towers 1,2 global collapse is the damage and gradual failure of the critical floor. This initial failure is what NIST exhaustively studied and provided a gravity alone explanation.

2) Second Phase of Towers 1,2 is the progressive collapse of the remainder of the structure to grade following the initial failure of the critical floor. Bazant mathematically describes this gravity alone global progressive collapse following the initial failure of the critical floor."



From the BZ paper I was reviewing:




"Introduction and Failure Scenario

The 110-story towers of the World Trade Center were designed to
withstand as a whole the forces caused by a horizontal impact of
a large commercial aircraft (Appendix I). So why did a total collapse
occur? The cause was the dynamic consequence of the prolonged
heating of the steel columns to very high temperature. The
heating lowered the yield strength and caused viscoplastic (creep)
buckling of the columns of the framed tube along the perimeter of
the tower and of the columns in the building core. The likely
scenario of failure is approximately as follows.
In stage 1 (Fig. 1), the conflagration, caused by the aircraft fuel
spilled into the structure, causes the steel of the columns to be
exposed to sustained temperatures apparently exceeding 800°C.
The heating is probably accelerated by a loss of the protective
thermal insulation of steel during the initial blast. At such temperatures,
structural steel suffers a decrease of yield strength and
exhibits significant viscoplastic deformation (i.e., creep—an increase
of deformation under sustained load). This leads to creep
buckling of columns (Bazant and Cedolin 1991, Sec. 9), which
consequently lose their load carrying capacity (stage 2). Once
more than half of the columns in the critical floor that is heated
most suffer buckling (stage 3), the weight of the upper part of the
structure above this floor can no longer be supported, and so the
upper part starts falling down onto the lower part below the critical
floor, gathering speed until it impacts the lower part. At that
moment, the upper part has acquired an enormous kinetic energy
and a significant downward velocity. The vertical impact of the
mass of the upper part onto the lower part (stage 4) applies enormous
vertical dynamic load on the underlying structure, far exceeding
its load capacity, even though it is not heated. This causes
failure of an underlying multifloor segment of the tower (stage 4),
in which the failure of the connections of the floor-carrying
trusses to the columns is either accompanied or quickly followed
by buckling of the core columns and overall buckling of the
framed tube, with the buckles probably spanning the height of
many floors (stage 5, at right), and the upper part possibly getting
wedged inside an emptied lower part of the framed tube (stage 5,
at left). The buckling is initially plastic but quickly leads to fracture
in the plastic hinges. The part of building lying beneath is
then impacted again by an even larger mass falling with a greater
velocity, and the series of impacts and failures then proceeds all
the way down (stage 5)."





According to his own description, the 5 stages are:

stage 1) Airplane damage, fire and fuel
stage 2) Creep buckling
stage 3) Majority of columns lose strength, building starts to move downwards
stage 4) First significant collision
stage 5) Collapse propagation
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

His words in the paper under review, not mine.

I prefer a slight modification to his 5 stages as I point out in the review. I do this to show that stages 2 and 3 are the most important to study from the point of view of CD.
>>>>>>>>>>>>>>>>>>>>>>>

Notice my conclusion in the review:

"Concerning stages 2 and 3, Dr Bazant offers nothing but a narrative. He narrates, or "talks" through the initial buckling sequence and this narration constitutes proof of nothing. It is just his opinion of what may have happened.

Bazant offers mathematical analysis for stage 4 only, the first collision, asking: If the top part falls for 12 feet and smashes into the bottom part, even if it makes a perfect landing can the columns elastic spring energy make the building bounce like a ball? and concludes it wouldn't. That's all.
................................

What BZ proves

BZ certainly does show that a cascading failure is most probable once condition "A" is met for any tall office building, but why would we be surprised at this finding?

What BZ doesn't prove

It offers no provable explanation for any of the following:

1) The collapse initiation mechanism of WTC 1 or 2 (the "how" of condition "A" for WTC1)

2) Anything concerning the collapse of WTC 7, including:

a) Fall time
b) Symmetry of collapse
c) Practically instantaneous collective column failure during collapse initiation, an extremely rapid lateral failure progression wave.
d) A small, compact, organized hill of rubble remaining after the fall of WTC 7.
e) The uncanny resemblance of the collapse to a controlled demolition.
f) Accidental hastily-released eulogy by the BBC of the collapse of WTC 7.

among other features.

It provides a narration of what he believes happened during the collapse initiation sequence, yet states it as fact. It provides no proof for this narration.

For these reasons, BZ cannot even remotely be considered as providing proof that no CD occurred on 9-11-01."
..........................................

Can anyone find something factually incorrect with these assertions? If so, what is incorrect?

If nobody objects to my conclusions, is it safe to assume that the readers agree with them?
 
There you have it, folks. Bazant and Zhou (2002) doesn't say anything about WTC 7, therefore it's OK for crazy people to believe in controlled demolition.

That's like saying I can't fix a TV set with a hammer, therefore hammers are useless.

I believe this is the rarely seen Denying the Antecedent logical fallacy -- about the stupidest example I've ever encountered at that.
 
R Mackey notes: "There you have it, folks. Bazant and Zhou (2002) doesn't say anything about WTC 7, therefore it's OK for crazy people to believe in controlled demolition.

That's like saying I can't fix a TV set with a hammer, therefore hammers are useless."


I'll rephrase it just for you:

What BZ proves

BZ certainly does show that a cascading failure is most probable once condition "A" is met for any tall office building, but why would we be surprised at this finding? It proves that tall office buildings cannot be expected to bounce, before or after 9-11-01.

A standard tall office building shouldn't be expected to bounce. What does that have to do with the question of controlled demolition?

What BZ doesn't prove:

It offers no provable explanation for the collapse initiation mechanism of WTC 1 or 2 (the "how" of condition "A" for WTC1 and WTC2).

It provides a narration of what he believes happened during the collapse initiation sequence, yet states it as fact. It provides no proof for this narration.

For these reasons, BZ cannot even remotely be considered as providing proof that no CD occurred on 9-11-01."


Of course this is obvious, but since many people cannot see what BZ proves and what it does not prove, I need to state the obvious.

Anything factually untrue in that statement, R Mackey? I'll be doing the same thing for the other 3 papers to help people see that the Bazant papers do not prove demolition did not happen, and the BV and BL(=BVReply) papers contain many untrue statements.

One of the most controversial untrue statements by Dr Bazant is in BLGB (2008) where he says:

"However, it remains to be checked whether the recent allegations of controlled demolition have any scientific merit. The present analysis proves that they do not."

When I asked one of the paper's authors, Frank Greening, why this untrue statement appears in the paper, he told me that inserting it was not his idea. He, as one of the authors, did not defend the statement.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>


So, we are in agreement that BZ addresses the "bouncing building" question well, but is a pretty useless tool to determine whether CD did or did not occur on 9-11-01?
 
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It takes a rare idiot indeed to criticize Bazant & Zhou because it doesn't cover WTC 7. That's not the focus of the paper.

It has been abundantly clear from the beginning that you don't understand it, or indeed the body of literature as a whole. But I never dreamed that your illogic was this fundamentally screwed up. I never would have guessed it possible.

It does explain a lot, however.
 
Major_Tom said:
One of the most controversial untrue statements by Dr Bazant is in BLGB (2008) where he says:

"However, it remains to be checked whether the recent allegations of controlled demolition have any scientific merit. The present analysis proves that they do not."

When I asked one of the paper's authors, Frank Greening, why this untrue statement appears in the paper, he told me that inserting it was not his idea. He, as one of the authors, did not defend the statement.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>


So, we are in agreement that BZ addresses the "bouncing building" question well, but is a pretty useless tool to determine whether CD did or did not occur on 9-11-01?
Click to expand...

Controversial only if you actively deny, oh, I dunno, the _other_ studies

And no, but just out of curosity, what IS the A condition?
 
R Mackey how about this statement:

"What BZ proves

BZ certainly does show that a cascading failure is most probable once condition "A" is met for any tall office building, but why would we be surprised at this finding? It proves that tall office buildings cannot be expected to bounce, before or after 9-11-01.

A standard tall office building shouldn't be expected to bounce. What does that have to do with the question of controlled demolition?

What BZ doesn't prove:

It offers no provable explanation for the collapse initiation mechanism of WTC 1 or 2 (the "how" of condition "A" for WTC1 and WTC2).

It provides a narration of what he believes happened during the collapse initiation sequence, yet states it as fact. It provides no proof for this narration.

For these reasons, BZ cannot even remotely be considered as providing proof that no CD occurred on 9-11-01."



No mention of WTC7. Just WTC1 and 2. I'd say these words may not make you happy, but the statements in quotes are true.

R Mackey, are we in agreement that BZ addresses the "bouncing building" question well, but is a pretty useless tool to determine whether CD did or did not occur on 9-11-01?

Remember R Mackey, I am not the person who cannot admit the papers contain any errors. You are.

I am not the one who thinks they prove no CD occurred on 9-11-01. You are.

There are so many holes in these papers I could drive a truck through them. You can call me "stupid and "an idiot", but I can answer every question I have posted to you whereas you haven't answered much of anything.

How much longer can you avoid that by calling me names? BV is next to be reviewed where Dr Bazant introduces "crush down, then crush up". You will have a lot more avoiding to do.


R Mackey writes: "It has been abundantly clear from the beginning that you don't understand it, or indeed the body of literature as a whole. But I never dreamed that your illogic was this fundamentally screwed up. I never would have guessed it possible."

Please enlighten us little people by answering these questions:

1) In BL, can you explain why Dr Bazant insists that crush down must be complete before crush up occurs. Does he mean this literally?

2) Do you consider the equations of motion in BV, equations 12 and 17, to be accurate for WTC1 considering the information in the ROOSD study?

3) Does Dr Bazant believe crush down, then crush up applies literally to WTC1? (or as just a "limiting hypothetical case in which the structure is best able to resist collapse")

4) Are the findings in the OOS study consistent with the claims of crush down preceding crush up in BV and BL?

5) Where in the BLGB arguments is the possibility of a CD based on ROOSD, exploiting the natural weaknesses of the building with minimal explosives, addressed?

If it is not, is it not true that the the arguments in BLGB are largely irrelevant when considering this type of controlled demolition?

6) When Bazant makes the following statement in BL, what does he mean?:

"So it must be concluded that the simplifying hypothesis of
one-way crushing (i.e., of absence of simultaneous crush-up),
made in the original paper, was perfectly justified and caused
only an imperceptible difference in the results. The crush-up
simultaneous with the crush down is found to have advanced
into the overlying story by only 37 mm for the North Tower
and 26 mm for the South Tower. This means that the initial
crush-up phase terminates when the axial displacement of
columns is only about 10 times larger than their maximum
elastic deformation. Hence, simplifying the analysis by neglecting
the initial two-way crushing phase was correct and
accurate."

Is he applying this to WTC1, or to just a hypothetical extreme case?

>>>>>>>>>>>>>>>>>>>>

Condition "A" is explained in the BZ review available here
http://www.the911forum.freeforums.org/review-of-bazant-and-zhou-t375.html
 
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You just wrote almost 700 words to say "I have no idea what I'm talking about." Most folks wouldn't go to such lengths to expose their ignorance, but you clearly like hearing yourself talk.

If you want to investigate "CD," take off your silly deerstalker cap and do it right. Come up with a hypothesis. Present your evidence. Evaluate your hypothesis against others using proper tests. Make predictions. Try to confirm your hypothesis based on those predictions.

You've done none of these. You have no hypothesis and no evidence. You've tested nothing, predicted nothing. Without this, all your complaining has absolutely no bearing on Dr. Bazant, his work, or the implications of that work. None of which appears to bother you, of course. This is why you're a Truther.
 
Major_Tom said:
a) Fall time
b) Symmetry of collapse
c) Practically instantaneous collective column failure during collapse initiation, an extremely rapid lateral failure progression wave.
d) A small, compact, organized hill of rubble remaining after the fall of WTC 7.
e) The uncanny resemblance of the collapse to a controlled demolition.
f) Accidental hastily-released eulogy by the BBC of the collapse of WTC 7.
Click to expand...

Got it.

So your paper and POV all boil down to these bits of incredulity? Is that correct?

A. Fall time. How long should the towers have taken to collapse? How does their collapse equal with any known CD?
B. what part of the symmetry of collapse are you talking about? The symmetry that destroyed the WTC complex and has no apparent symmetry or the symmetry of the collapse o WTC7 which managed to hit two adjacent buildings, including one on the roof.
C. Practically instantaneous... I love those weasel words. Can't really be quantified and means almost whatever you want... like "near" freefall.
D. small? Compact? rubble pile for wtc7. How is an 8 story tall debris pile small? How is a compact debris pile able to have struck fiterman hall across the street on the ROOF?
e. Uncanny resemblance to CD... unless you count out the things which are obvious in CD. Like a rapid fire series of booms right before the building collapses. Like a rapid fire series of bright flashes in sequence before the building collapses. Like having survivors in the stairwells talk about the wind, but leave out the sound of a rapid fire series of booms. Or the lack of barotrauma in any survivors of the collapses.
f. Oh yes... I forget.. the MSM is in on it and they had a predone script.... not that accidents happen in the heat of the moment and they were EXPECTING the building to collapse from NOON.
 
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