jaydeehess
Penultimate Amazing
Why? Is there any reason to believe this could have happened?![]()
Not that I can envision, but this is the 911 conspiracies subforum.
Why? Is there any reason to believe this could have happened?![]()
This is true. I think the first order in that discussion would have to be compelling factual evidence why anyone would entertain the notion.Not that I can envision, but this is the 911 conspiracies subforum.
This is true. I think the first order in that discussion would have to be compelling factual evidence why anyone would entertain the notion.
As you know, this has never happened.
I see no evidence of CD... however... I suspect a CD or some sort of devices could produce a ROOSD.
ROOSD is silent on initiation and I don't see many compelling explanations for the mechanisms of the initiation. I watched the PBS video and I saw some junk explanations and suggestions such as melted columns or steel...
This is the discussion that needs to be opened... how did the mech damage and the heat released the "ROOSD" mass? What mechanisms were in play? If it was frame distortion this would for sure rule out a CD cause.
I see no evidence of CD... however... I suspect a CD or some sort of devices could produce a ROOSD.
ROOSD is silent on initiation and I don't see many compelling explanations for the mechanisms of the initiation. I watched the PBS video and I saw some junk explanations and suggestions such as melted columns or steel...
Someone should comment on how much strength could be lost in a column related to the heat that was present... an indeterminate value. But my hunch is that the initiation was more a structural failure from the frame being distorted by heat.. than losing axial strength from it.
This is the discussion that needs to be opened... how did the mech damage and the heat released the "ROOSD" mass? What mechanisms were in play? If it was frame distortion this would for sure rule out a CD cause.
Agreed but take care that we don't re-awaken that nasty bit of trickery that says "If it is not conspiracy it shouldn't be here".
..selectively directed against alleged "truthers" of course.
The forum policy was and remains "All 9/11 related matters go here". And, if we want to ban technical discussion it has to be banned for everyone. Not just alleged truthers when some debunkers cannot rebut the truther claims.
So away with the "Microspheres" and "Millette Dust Study"
threads for starters.
...just to censor M_T??? I think not.![]()
Thanks. I've been reading the history and sadly I've seen the number of times people have tried to play the card. Hence my word of caution. My apology for misreading your intent.When I thought about this I really didn't consider it on this site at all. I'm talking about an engineering forum, outside of this "skeptic" world.
Well, in this thread, on this forum, I get it, ozeco41 gets it, JSO gets it, DGM gets it, Newton's Bit gets it, rwguinn gets it, pgimeno gets it and beachnut gets it.Obviously FEMA gets it, and so does NIST
Where's the beef? just tfk?
from this post"On another matter, we ordinarily start with the simplest hypothesis and stik with it until some evidence shows the hypothesis must be modified. In the case of the top portion, the simplest is that it stayed on top most of the way down; say with the roof at around floor 25. Until someone develops some actual evidence to the contrary, I'll stick with that rather than unending speculation and new simulations of the resulting hypothesis."
from this post"Better to call the section cushed, rather than compressed, as it is inelastic. It did contain, for the most part, the core columns; only a few were bypassed."
"Albert Einstein once said something to the effect that a model should be as simple as possible, but no simplier. The B&V crush-down equation meets that criterion as long as one only considers measurements taken on the antenna mast. With your careful observations of perimeter wall sections breaking off at and above floor 98 and OneWhiteeEye's observation earlier on this thread to the effect that this led to a inhomogeneity in the structure, I then, as reported earlier on this thread, in effect moved zone C up to start at floor 102. That fits the antenna tower measurements and also (approximately) the additional observation that OneWhiteEye posted earlier on this thread, regarding the SW corner of WTC 1."
"So, the simplest possible model for WTC 1 collapse works very well even though I now conclude that some 4+ floors of early crush-up occurred due to the inhomogeneity introduced by missing perimeter wall sections. But not more early crushup than that. Once those were crushed, the homogeneity is re-introduced so that Bazant & Le then applies. I think. It's a point that needs checking."
from this post"More complex equations simply are not required. Parsimony suggests the B&V crush-down equation with vertical avalanche resisting force together with starting the crushing front around floor 102, being good enough for the data in hand, is indeed good enough."
from this post"Assuming homogeneity, Bazaant & Le show thaqt zone C is almost industrucible. That's mechincs for you. The sturcture obviiously was not homogeneous and you have, in other threads, shown some distruction along the west and north walls. In of itself that mass loss is not important, but it does mean the floor trusses in those areas have been weakened. So an average of about 4--6 stories above floor 98 do not come close to satisfying the homogeneity condition. Fine. consider then that zone C is from floor, say, 102 up. To keep the equation simple, assume crush-down begins from there. As I mentiioned in this thread yesterday, this works well enough to match the additional observations by OneWhiteEye.
"
from this post"Zone C simply disappears into the obscuring dusts. Not sufficient reason to assume it is being crushed first. If sufficiently close to homogeneous, then from Bazant & Le it is not being crushed at all."
"OneWhiteEye --- I've been thorugh all this before. Homogenization is fine when the tilt is taken into account; crushing proceeded on 3+ floors simultaneaously which is surely better represented by homogenization that by stepwise floor-by-floor model. However, both give essentially ythe same results; shagster actually went to the effort of running his own version of Greening's ideas using minifloors to demonstrate this; although, after some study, this is analytically obvious.
from this post"The issue of early crush-up never seems to die, does it? The problem is that it would have to proceed against the force of gravity, not with it. Instead what you seem to have noticed in frame 1007 is a lack of one dimensionality, with zone C west perimeter wall going outside the lower portion, yes? That actually does not trouble me, yet.
"
from this post"No sign of zone C falling aprat as long as it can be seen. Unlike the case of WTC 2."
from this post"Major_Tom ---
Do you doubt Newton's Laws?
Do you doubt http://en.wikipedia.org/wiki/D'Alembert's_principle?
Do you doubt the applicability of the four simplifying assumptions in B&V?
If not, the conclusion of little early crush-up of zone C follows.
Further, the timing studies in BLGB show that most of zone C mass must have stayed on top most of the way down."
from this post"As for the core punching through the roof, I conjecture this occurred when the upper mechanical floors and up to the roof encountered the greater resistance offered around floors 75--79, about 30 stories (about 110 meters) down. No air escaping through such a puncture will be separately observable in any of the photos, IMO."
"The west and north walls peeled away sufficiently rapidly that deebris tended to move west and north near the spire. Similarly, but to a lesser extent, to south and east. There actually wasn't a gaping hole, just less density and in particular no structural steel to break connections."
from this post"OneWhiteEye --- B&L show little inital crush-up, not none at all. Since it is so small, the argument is that the crush-down only in B&V is a valid approximation."
from this post"Major_Tom --- B&V have four simplifying assumptions which lead to the crush-down ODE. These assumptions are reasonable for WTC 1 but not, by video timing, for WTC 2 after a few seconds. In the case of WTC 2 it is clear from the ABC video of the collpase proceeding down to the Mariott rooftop level that the collapse was proceeding much too slowly; the inference is that the top section broke apart and fell off rather early on.
But as BLGB indicates, this could not have happened to WTC 1 or the timing would be off."
from this post"OneWhiteEye --- I'm not the one with any doubts about the matter: there can be no significant early crush-up."
from this post"Read Bazant & Le to understand why zone C can be consired to be essentially rigid during crush-down.
I offered to start a thread about how to build a table-top demonstrator that will allow one to see that,
indeed, zone C remains intact during crush-down. I didn't bother when I realized that nobody here would bother to actually build it, test it, and in the process dicover that the application of Newton's laws and
d'Alembert's principle in Bazant & Verdure agrees with reality."
from this post"See Bazant & Le for a further exposition of why early crush-up is very small. It is, I admit, a difficult
point. But it is similar to a house riding down a landslide for which many examples have occurred in southern California."
Wow, I had forgotten just how clearly Major_Tom was eviscerated at the start of this thread.
This failure mode has been discussed for a very large period of time and it just a rehash of what everyone who wasn't delusional already knew. Bazant and Zhou talk about the column failure mode as the limit state as, "nlikely though such a distribution may be, it is nevertheless the most optimistic hypothesis to make because the resistance of the building to the impact is, for such a distribution, the highest."
Bazant and Verdue states that, "The kinetic energy of the top part of the tower impacting the floor below was found to be about 8.4 larger than the elastic energy absorption capability of the underlying story," and the the purpose of the Bazant and Verdue paper is not to describe the WTC collapse, but rather to create "a theory describing the progressive collapse dynamics" as this would be "very useful for other purposes, especially for
learning from demolitions".
Indeed. If any thing, his "paper" only provides evidence as to why the collapse was quicker than expected in the axial column-to-column scenario.
NB's interpretation of BV is quite interesting, since I've exchanged hundreds of posts with David Benson on another forum where he uses it to match drop data for WTC1. He claims to communicate with Dr Bazant and he is co-author with Dr Bazant and Dr Greening on the follow-up paper for BV.
He seems to see things differently than you.
Interpretation? Try reading the introduction. FFS I QUOTED the damn paper.
Yes, and the abstract and the paper agree with what I said. Your confusion is probably due to not knowing what the definition of paradigm is.
Bazant and Verdue sets out to model and understand progressive collapse. Not prove how the WTC collapsed. It uses the WTC only as a paradigm. I.e. an example, a model, a pattern, etc etc. It then applies the conclusions of this model to other buildings, as that is the stated purpose of this model.
I do have a problem with Major_Tom's arguments regarding Bazant, as they are incorrect and based on reading truther websites of the paper rather than the paper itself. I have a problem with his phrase "OOS flooring" because he just invented it. "Long-Span Trusses" is common. Or hell, he could just say "floor". 60' spans aren't that uncommon.
Is anyone else interested in wasting any more of their time with this? I'm not. Femr2 is asking for evidence of things that happened IN THIS VERY THREAD. I'm not going to play that game.
Major_Tom wants to argue against a strawman Bazant. Repeated quotes from the paper (some of which he has provided) doesn't seem to persuade him that he is looking at the papers wrong. He also wants to say that he's the first person to come up with the idea of the columns not hitting each other.
...
If you'll excuse me, I'm going to go off and do something more productive than talking with liars and boasters now.
You're moving the goalposts. We've been talking about the claim of axial-column impacts. Not the crush-up / crush-down hypothesis.
Incidentally, you haven't done anything to debunk crush-up / crush-down. Even in a floor failing model, crush-up / crush-down still applies due to the simple fact that there is very little force being applied to the upper block. The rubble layer is still doing all the destruction.
Yes, the floors failed in the collapse, not the columns. Congratulations, you wrote a paper describing what the vast majority here has been saying since before you joined this forum.
Actually I accused you making up words to sound like an expert with regards to the "OOS flooring" term. It's not used in engineering. Not that you're a dolt. I'd prefer to use the term "charlatan" now that you mention it.
Please see my previous statement of, "Do you read what ANYONE writes?" You have a seriously bad habit.
It's in BV and BL. You were talking about axial-column impacts. I was taking about BV and BL, and the topic of the thread: The study
If you want people to keep interacting with you, stop moving goal posts over and over again. This is what you wrote.
You are a lying liar. We challenged you on your fraudulent claim on the buckled columns concept. YOU brought up the upper block / lower block. This is a non-sequitur. It would make an equal amount of sense for you to bring up Bazant's middle name as an argument. Unfortunately, the way you do it you just come across as a dishonest charlatan. Which, by the way, you are.
Newtons Bit and R Mackey claim that the study provides no new information that was not known before.
Unless participants in the JREF forum have abandoned Bazant's opinions stated in BV and BL, this is provably false.
>>>>>>>>>>>>>>>>>>>>>>>>>
CRUSH DOWN FOLLOWED BY CRUSH UP, 2006-2010, R. I. P.
BAZANT AND VERDURE EQUATIONS OF MOTION, EQS 12 AND 17, 2006-2010, R. I. P.
If we accept the ROOSD study as accurate, one logical consequence is that the claims in the papers BV and BL are incorrect.
...
Let's ask R Mackey and NB the following questions and see what they have to say:
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 BL, equations 12 and 17, to be accurate considering the information in the ROOSD study?
3) Is the following statement true or false:
Dr Bazant believes that a crush-down phase must continue to completion before a crush up phase can begin.
If you answer false, please provide evidence to the contrary.
4) Is ROOSD consistent the claims of crush down preceding crush up in BV and BL?
We've already posted quotes from people on this very forum that were talking about the vast majority of the columns not buckling in the collapse. You've acknowledged this fact. Do you have an incredibly short memory or do you routinely alter history in your mind to fit the new argument you wish to make?
If we accept the ROOSD study as accurate, one logical consequence is that the claims in the papers BV and BL are incorrect.
You have said so.
ffs Read the paper. Here, let me explain it to you:
The upper block is accelerating at near g. This means that there is very little force being applied to it. We can imply that the absolute maximum height of destruction occurring through the upper block will happen at a rate equal to (g - a). However the upper block has some residual strength. This force is much less than the original capacity upper block which is somewhere in the neighborhood of 3*m*g.
There will be, during the initial stages of the collapse that forms the rubble layer, destruction on both the upper block and lower block. But once it gets moving? Not so much.
You've provided no information on how this is incorrect.
And... I'm done with this truther. Major_Tom can admit that people were talking about non-buckled columns prior to him even joining here, then still claim that his idea is unique and special the next day.
I'm not going to go around and around with another reality changing truther like Heiwa.
I don't think there's any other kind at this point.
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. As if we hadn't explained this to practically every Truther who ever lived a million times each.
Ah well. I guess it keeps them occupied, at least.
Enlighten us, R Mackey. Can you answer 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 BL, equations 12 and 17, to be accurate considering the information in the ROOSD study?
3) Is the following statement true or false:
Dr Bazant believes that a crush-down phase must continue to completion before a crush up phase can begin.
If you answer false, please provide evidence to the contrary.
4) Is ROOSD consistent the claims of crush down preceding crush up in BV and BL?
Teach us how quotes like
"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."
Represent a limiting case.
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.
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".
Hey, Major_Tom learned what Bazant was talking about when he said "paradigm", amazing!
You are a'ing liar.
Did he say anything worthwhile? I put him on ignore.
Your book makes it appear are the only one who understands 911, yet you can't decide, was it CD, or not CD. Did you debunk the inside job fantasy yet, or is the book not finished? Was the "gravity collapse an illusion" as you said? Have retracted that yet?...
And that was the end of the exchange until now.
In at least one of Beachnut's latest posts he does agree with the concept.So you are willing to throw TFK under a bus at this point...But you keepbeachnut?
Have you read his posts from page 1?
Your comment can be fact-checked using informatiion found on a few threads.
These are some interesting and revealing exchanges I have had on the subject of the latter Bazant papers and the WTC collapses:
......
............Looking at the crushing blocks compared with the observations that are now documented, it is stunning that this passed for a model on building mechanics at one time (in 2008) and that it passed the peer review process:
[qimg]http://www.sharpprintinginc.com/911/images/photoalbum/13/BV_fig1.png[/qimg]
People tend to be detached from the history of the collapses in 2 ways:
1) They are detached from the visual record of events
2) They are detached from written records of events
The resulting atmosphere allows historic revisionism to flourish unchecked. In other words, anyone can say anything they want and there is little effort or capacity to check the claim for accuracy. Groups of like-minded people emerge under the banner of some common, shared beliefs. Since the groups are detached from their own visual records and written histories of the events, they make little or no effort or have little or no ability to fact-check their own claims.
In at least one of Beachnut's latest posts he does agree with the concept.
Throw tfk under the bus? No, I simply disagree with him.
However, that's beside the point. How could you so completely miss the point of my post?
It isn't just TFK that cannot perceive a contradiction between Bazant's latter papers on the WTC collapses and the OOS propagation model.

I don't give a rat's sphincter about your amatuer psychoanalysis of your detractors.From part 7 of the book:
In this forum there is a third form of detachment. People generally don't bother to read each other's posts.
So the #### what?It isn't just TFK that cannot perceive a contradiction between Bazant's latter papers on the WTC collapses and the OOS propagation model.
Yeah, so?Beachnut was openly allowed to write what he did for 4 years on any thread in which I or Femr2 participated.
Have you read the posts of TFK, Beachnut, R Mackey, Newton's Bit, Myriad or Dave Rogers or David Benson? I have reproduced some and I will reproduce the others shortly. You must disagree with them, too, since no poster among them was able to admit there is a contradiction between Bazant's latter papers and the OOS model. How could you so completely miss the point of their posts for more than 4 years?
It is now 2014 and there is no written evidence that R Mackey, Newton's Bit, Dave Rogers, TFK, Beachnut, David Benson, or Bazant himself can perceive a contradiction between the latter Bazant papers and the OOS propagation model.
Beachnut was openly allowed to write what he did for 4 years on any thread in which I or Femr2 participated.
What... the OOS Collapse Propagation Model can't debunk CD and the old gravity collapse is an illusion claim. Or did it?Do you think you weren't?
October 2001, ... because the structure is a framed tube with floor beams of large spans, the impacted floors may collapse ahead of the tube, thus depriving the tube wall of its lateral support against global buckling.
Did the OOS model debunk this fantasy, or not. Simple question. Impossible question for the author of the book.the supposed "gravity-driven collapse" is a mere illusion to mask an intentional act so barbaric, so inhumane and morally impoverished that the fabled characteristics of Satan come to mind.