Critical Errors and Omissions in WTC7 Report Uncovered

[qed]

@Mick West

Is the rejection of the NIST reports as scientifically worthless really a great loss to 9-11 debunkers?

I think we, as scientists, should reject them as unscientific and carry on.

 

[Mick West]

@Mick West

Is the rejection of the NIST reports as scientifically worthless really a great loss to 9-11 debunkers?

I think we, as scientists, should reject them as unscientific and carry on.

You can't throw the baby out with the bathwater. There's a vast amount of very good work in there. Finding that they overemphasized the role of the 44-79 unseating does not invalidate the rest of the work.

The basic hypothesis is still very well grounded, and the actual analyses are quite consistent. Where I think a possible problem has been identified by Gerry is just in the summaries. The problem is that people are extrapolating from the summaries, rather than looking at the actual data and discussion from which those summaries are distilled.

 

[Mick West]

Keep on topic please. No need to descend to discuss the philosophy of science.

 

[Mick West]

Did I just hear a penny drop ?

Not really. Just more clarification of the situation. NISTs summary of a probable collapse sequence seems to place unwarranted emphasis on the failure of that girder. The sentence "Further thermal expansion of the floor beams pushed the girder off its seat, which led to the failure of the floor system surrounding Column 79 on Floor 13.", and the omission of the other damage, does not seem justified, based on the rest of the report.

 

[gerrycan]

You can't throw the baby out with the bathwater. There's a vast amount of very good work in there. Finding that they overemphasized the role of the 44-79 unseating does not invalidate the rest of the work.

No way. The problem here is that you are not aware enough of NISTs explanation. Can you please explain what would have happened if the girder at C44-79 had not failed and continued to provide lateral support to the column.

The problem is that people are extrapolating from the summaries, rather than looking at the actual data and discussion from which those summaries are distilled

The problem is that you are taking your data from whichever hypothesis suits you best, and goodness knows NIST have enough of them.

This thread has went from half decent debate, to ridiculous denial. Mick the point was proved when you grudgingly did the thermal expansion sum and the problem now is that you can't stand to admit that NIST were wrong. You are blindly defending a story which is just ridiculous. I try to answer every question that gets put to me. You cherry pick which ones sut you. I address NISTs conclusion and what they have publicly stated - You look through the many hypothetical scenarios that NIST put out and choose the one that suits you.
The problem now in this thread is not proving that NIST made critical errors and omissions. The problem is your inability to admit that they, and you are wrong. All you can do now is retreat into denial, that's not scientific and frankly it is not honest. You are not an engineer Mick, and that shines through in your lack of understanding of the consequences of the omissions and errors that NIST made.
You just do not want to admit you are wrong, NIST have the same problem. You make admissions but you do not acknowledge the implications of them, NIST have the same problem. When faced with logic and hard engineering facts and figures you recoil into semantic avoidance or just ignore them, NIST have the same problem. If being disingenuous were a crime, it would not just be NIST that were facing the prospect of court Mick.

 

[Mick West]

No way. The problem here is that you are not aware enough of NISTs explanation. Can you please explain what would have happened if the girder at C44-79 had not failed and continued to provide lateral support to the column.

Since the girder only provided support in the north direction, then the column would likely still have buckled to the east. Even if the girder did not walk off its seat.

Note the five girders directly below F13 44-79 girder are all still intact, and also offer support only in one direction.

And there's no need to get personal. But if you don't think I can possibly understand, then who on earth do you consider to be the audience for your videos? Should you not add an "structural engineers only" disclaimer to the start?

 

[Hitstirrer]

Not really. Just more clarification of the situation. NISTs summary of a probable collapse sequence seems to place unwarranted emphasis on the failure of that girder. The sentence "Further thermal expansion of the floor beams pushed the girder off its seat, which led to the failure of the floor system surrounding Column 79 on Floor 13.", and the omission of the other damage, does not seem justified, based on the rest of the report.

Quite.

But as NIST did place FAR less emphasis on the multitude of other issues that must have been ongoing in there we can fairly safely take the view that they considered them to be incapable of jointly and severally causing such a global collapse. Otherwise they would have said that - wouldn't they ? As they were in full possession of all the facts of those other events but chose to place total emphasis on a single connection we must take note of that surely. Aftter all, they had years to write, re-write, and edit that report. NIST chose, quite deliberately, and no doubt after many committee meetings, to print those words in their 'final report'. Yet others in here are now saying that by doing that they made a mistake. All that gerry is doing is to examine those deliberately printed words to see if they stand scrutiny.

And there is the crux of this thread.

 

[Pete Tar]

I decided to go back to the start of this thread after this last post from Jazzy to see how we got to such a juvenile point. Fascinating really. At the start, much energy is expended attempting to disprove gerry's original information about stiffeners. As it was gradually accepted that they should have been included in NIST's drawings and modelling, the thread moved to suggest that stiffeners would make no difference anyway. When it was shown that they would have a massive difference, a move to attack the professionals saying that was seen. A demand was made to know the names of others concurring, and requiring to be informed of the quotes from those people. Having reached the point where gerry's original input was in danger of being conceded the only recourse was to look for an escape route. That was attempted by denying that the girder both dropped from its seat and also that it was the initiating event. Much heel digging in was then seen which required them to totally ignore NIST's own words in all their reports and presentations. That went on for some time until once again danger of conceding loomed. Another escape tunnel was required. That was found in the shape of a protracted debate on the meaning of 'initiation'. Whether 'floor' falling meant the girder supporting that floor fell or not. Strong support in the form of 'appeal to authority' from NIST, using spin, to re-name the real inititing event of the girder and floor system dropping from 13 to 12 so that people could claim that the buckled column was the initiating event thus avoiding having to concede NIST's own words quite specifically saying many times that the girder was pushed off its seat. When danger loomed yet again the old favourite of 'lets debate theoretical temperatures' ploy was pulled from the box of debunker tricks. You guys would have made excellent theologians when debating how many angels can dance on a pinhead was all the vogue.
And there we have it. If you can stand the pain go and re-read Jazzy's last entry and you will get my gist.

Why does any WTC thread always end up with a meta-analysis of the psychology and motivation of the sceptical posters?
Is it meta to point out that this is a predictable occurrence and will happen every 1.3 pages?

 

[Josh Heuer]

Why does any WTC thread always end up with a meta-analysis of the psychology and motivation of the sceptical posters?
Is it meta to point out that this is a predictable occurrence and will happen every 1.3 pages?

Err...same reason posts like yours and mine come along and derail the topic
And the same reason debunkers take the time to point out how 'all CTs act this way or think this way' etc.

Actually, no, I take that back. Hitstirrer's post was a legitimate summation of the posts leading to the topic reaching the point it was at. What's wrong with that?
Is any of what they said wrong? And if so, care to point out what?

 

[gerrycan]

Since the girder only provided support in the north direction, then the column would likely still have buckled to the east. Even if the girder did not walk off its seat.

If the drawing above, from the people who can't tell the difference between 11 and 12, and who can't read structural drawings, and are trying to get you to believe their story, is a true illustration of what happened that is.

And there's no need to get personal. But if you don't think I can possibly understand, then who on earth do you consider to be the audience for your videos? Should you not add an "structural engineers only" disclaimer to the start?

Sorry if I seem to be getting personal. This has been a steep learning curve, and I understand that, and I have a lot of admiration for the way you have grasped the concepts and to an extent defended their story. Most forums would not do this, and the reason that I am debating here is because this seemed like a forum where truth would be accepted once proved. But denial in the face of the undeniable is fast eroding your integrity.

I am not a structural engineer Mick, my background is more electronic and mechanical, although I was in construction for a while. If i thought for a second that this information was beyond you, I would have abandoned this thread long ago. Do you seriously think that we have sat on this information for over 18 months and not went through every possible scenario that you could apply to it? Don't you think we have done due diligence in terms of the engineering behind these claims?

If you are failing to see the implications of the information that has been presented to you, there are 2 possibilities. Either the case has not been put clearly enough to you and explained properly, or you just don't want to see the implications. Just now I am leaning toward the latter. Again, kudos to you for this debate, but there comes a time when you just have to throw your hands up and admit that NIST were wrong, and accept the obvious implications of their serious errors and commissions. omissions. ( i almost decided to leave that typo in )

 

[Pete Tar]

.... It's been a huge misrepresentation. Sure they describe it as failed, but they also describe a lot of other girder and beams as failed, including the matching girder to the south, which failed around 30 minutes earlier:
....

Is it too much to expect that any contributors to the NIST report could come here and explain and clarify their position in regards to the report and this thread's focus?

 

[Jazzy]

much energy is expended attempting to disprove gerry's original information about stiffeners

Not by me.

the thread moved to suggest that stiffeners would make no difference anyway. When it was shown that they would have a massive difference, a move to attack the professionals saying that was seen.

Not by me. I have always said that the presentation itself was a tiny and meaningless children's trick, using, as RP so neatly clarified, a focus on a tiny detail, which may be disproved, to draw attention away from the effects a long and sustained fire has on insulated steel - because the hidden agenda is to minimize the effects of fire in order to make a later, and presently very distinctly absent, case.

A demand was made to know the names of others concurring, and requiring to be informed of the quotes from those people. Having reached the point where gerry's original input was in danger of being conceded the only recourse was to look for an escape route. That was attempted by denying that the girder both dropped from its seat and also that it was the initiating event. Much heel digging in was then seen which required them to totally ignore NIST's own words in all their reports and presentations.

You don't like the word "fire". You can never read the words: "fire damage".

Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. The unsupported girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor

I will summarise the sequence.
NIST said " the floor beams to the east side of the building expanded enough that they pushed the girder connecting
Columns 79 and 44 to the west on the 13th floor".
NIST said " This movement was enough for the girder to walk off of its support at Column 79".
NIST said " The unsupported girder and other local fire-induced damage caused Floor 13 to collapse, beginning a
cascade of floor failures down to the 5th floor."
NIST said " This left Column 79 with insufficient lateral support, and as a consequence, the column
buckled eastward".
Look for the key words above. " beams expanded - girder pushed - girder walk off - cascade of floor failures - column buckled.

See? "other local fire-induced damage" has disappeared. It's off your list...

That went on for some time until once again danger of conceding loomed. Another escape tunnel was required.

In your dreams.

That was found in the shape of a protracted debate on the meaning of 'initiation'. Whether 'floor' falling meant the girder supporting that floor fell or not. Strong support in the form of 'appeal to authority' from NIST, using spin, to re-name the real initiating event of the girder and floor system dropping from 13 to 12

I think it was Floor 14 to 13. Whether heating or cooling the whole floor system was expanding in some places and contracting in others. This normally will put paid to pinning over time, especially at elevated temperatures. Bulk movements of floors due to expansion and contraction would have been considerable, and the forces applied to columns also. The beam temperatures were high enough for them to sag in places, and that too applied very large forces.

so that people could claim that the buckled column was the initiating event

The initiating event was WTC1 striking WTC7. The rest was a sequence of fire movement and spread, with local fire-induced damage, and the consequences of that fire-induced damage..

thus avoiding having to concede NIST's own words quite specifically saying many times that the girder was pushed off its seat.

Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. The unsupported girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor

When danger loomed yet again the old favorite of 'lets debate theoretical temperatures' ploy was pulled from the box of debunker tricks.

I've always said the place was on fire.

You guys would have made excellent theologians when debating how many angels can dance on a pinhead was all the vogue.

Nah. I'm not going to get myself banned. I've a fondness for Harvey because he never lets a good banning get in the way of his self-expression.

go and re-read Jazzy's last entry and you will get my gist.

It's elsewhere. Read this.

 

[Hitstirrer]

Is it too much to expect that any contributors to the NIST report could come here and explain and clarify their position in regards to the report and this thread's focus?

I'm afraid there is zero chance. Whoever turned up would have to bring along the drawings that would put the debate to bed - Oh - and admit that the girder had stiffeners welded to it.

 

[gerrycan]

Is it too much to expect that any contributors to the NIST report could come here and explain and clarify their position in regards to the report and this thread's focus?

We have requested correction and asked repeatedly for clarification on this issue. They will admit freefall, they will admit the sea tplate mistake, but they know, that as soon as they admit that these plates even exist, their report is invalidated. It is very unfair, and if I were American, I would be ashamed that a federal agency would tell these lies, and further ashamed that they seem to be above accountability to their employers, who are after all, the American population.

 

[Pete Tar]

...

Actually, no, I take that back. Hitstirrer's post was a legitimate summation of the posts leading to the topic reaching the point it was at. What's wrong with that?
Is any of what they said wrong? And if so, care to point out what?

The whole thing was just a sneering and biased mis-characterisation, that didn't actually debate the facts being debated, so, yeah, that.
It always seems impossible to resist resorting to that superior condescension when people aren't convinced by your evidence.
A rhetorical attack on their psychology is irrelevant to the facts.

(which of course, I am somewhat guilty of in pointing this out. Oh the meta.)

 

[gerrycan]

Since the girder only provided support in the north direction, then the column would likely still have buckled to the east. Even if the girder did not walk off its seat

Hang on a minute, that one nearly got by me there. NO WAY. We need to take a look at the drawings Mick, you know this connection reasonably well now, go and look again and repeat this statement. In fact, do it on video, I would love to see you on you tube trying to say that and try to keep a straight face.

 

[Hitstirrer]

The whole thing was just a sneering and biased mis-characterisation, that didn't actually debate the facts being debated, so, yeah, that.
It always seems impossible to resist resorting to that superior condescension when people aren't convinced by your evidence.
A rhetorical attack on their psychology is irrelevant to the facts.

OK. I'm new here. I didn't realise that old members could analyse new members psychology by saying that I - "resorted to superior condescension" But new members are not allowed to do that. Sorry. It won't happen again.

But seriously, I thought that a summary showing much drifting from topic followed by an appeal to stay on topic in future would have been welcomed.

 

[Pete Tar]

Well, nevermind, let's drop it.
It just equates to me as a kind of distraction and a way of belittling the 'opponent', and a passive-aggressive way of expressing frustration to opposition. It's not always and can be valid, but it is an observable pattern in these contentious topics. I will try to avoid it myself as it's easy to do.

 

[Hitstirrer]

Well, nevermind, let's drop it.
It just equates to me as a kind of distraction and a way of belittling the 'opponent', and a passive-aggressive way of expressing frustration to opposition. It's not always and can be valid, but it is an observable pattern in these contentious topics. I will try to avoid it myself as it's easy to do.

Thanks for that. Dropped.

 

[kawika]

Since the girder only provided support in the north direction, then the column would likely still have buckled to the east. Even if the girder did not walk off its seat.

Note the five girders directly below F13 44-79 girder are all still intact, and also offer support only in one direction.

Note the five girders directly below F13 44-79 girder are all still intact, and also offer support only in one direction.

One direction (north) would be one girder--- no beams, no floor system occupying the NE region. That floor system provided eastern support.

Besides, what is being argued here is all based upon a cartoon, 100% speculation that itself is based upon 100% speculation about fires (moving through many interior individual offices), which are based upon a very small number of photos and videos taken at various times throughout the day.

Those photo and video times are the subject of much extrapolation. NIST used a system called CUMULUS to try to associate imagery with known events. Highly speculative to say the least.

See NCSTAR 1-9 (NOV 2008), Page 209, PDF page 253, where it says the fire in the N/E region of floor 12, near C44, (heating the F13 beams and girder) "...lasted for roughly 15 minutes..". And this was around 3:15PM, more than 2 hours before collapse.

The fire duration has been advanced way beyond reasonable. They use 4 HOURS for the model. They use 4 hours because they couldn't even get 3.5 hours to do what they decided in advance.

 

[gerrycan]

I have no comment on the technical accuracy of what you're putting forward - I am illiterate in this conversation, but I would like to say that this is the way to present an argument against the official story - no hyperbole, no ideology, no mention of Gulf of Tonkin or mind-control by mainstream media, just the brass-tacks.
It's refreshing - even if you turn out to be mistaken.
I'll follow with interest.

This thread was great at the point this comment was made, but it is now being allowed to degenerate into meaningless point scoring. This is being allowed to happen because this information is challenging to people on here who are more interested in winning a debate than actually getting to the truth about what happened to wtc7. Can we please limit the focus to that which is pertinent to the claim rather than drifting off into irrelevance. Seems to me that every time the debunkers are cornered is when it is allowed to go off topic. Why do we not just have this debate in an open live forum as i suggested. I am willing to debate any of you guys out in the open. We have studied this and researched deeply. We have scientific credibility behind this. We have real engineering behind this. If it is allowed to continued to drift, then I am off.

 

[gerrycan]

Not by me.


Not by me. I have always said that the presentation itself was a tiny and meaningless children's trick, using, as RP so neatly clarified, a focus on a tiny detail, which may be disproved, to draw attention away from the effects a long and sustained fire has on insulated steel - because the hidden agenda is to minimize the effects of fire in order to make a later, and presently very distinctly absent, case.

(emphasis added)
If i responded in kind to this i would run the risk of being banned. This is not the level playing field that I thought it was. Disappointed. If you want this forum to have any credibility you need to do something about this guy.

 

[Mick West]

Hang on a minute, that one nearly got by me there. NO WAY. We need to take a look at the drawings Mick, you know this connection reasonably well now, go and look again and repeat this statement. In fact, do it on video, I would love to see you on you tube trying to say that and try to keep a straight face.

I was basing my statement on FL13 being just like FL12, if the girder did not drop. The two cases below. Of course it all depends on what is going around the column in every direction.

 

[gerrycan]

I was basing my statement on FL13 being just like FL12, if the girder did not drop. The two cases below. Of course it all depends on what is going around the column in every direction.

This assumption has no basis in engineering reality. NIST said that the girder DID drop, that it didn't in a hypothetical scenario that you choose because it suits you to, means nothing. If this debate was taking place on a level, fair playing field, it would be over by now. The frustration that it is not, is making me lose interest to be honest.

 

[Mick West]

This assumption has no basis in engineering reality. NIST said that the girder DID drop, that it didn't in a hypothetical scenario that you choose because it suits you to, means nothing. If this debate was taking place on a level, fair playing field, it would be over by now. The frustration that it is not, is making me lose interest to be honest.

But I was responding to you asking me "what would have happened if the girder at C44-79 had not failed and continued to provide lateral support to the column."

 

[Pete Tar]

...Why do we not just have this debate in an open live forum as i suggested. I am willing to debate any of you guys out in the open. We have studied this and researched deeply. We have scientific credibility behind this. We have real engineering behind this. If it is allowed to continued to drift, then I am off.

This is an open live forum isn't it? What would the difference be?
Why do you think this is not a fair and level playing field?
Thread drift happens organically as different posters interact, it's not deliberate derailing. Saying it's allowed to happen because people can't handle their minds being blown by your truth is also adding to the derailing.

You can always get it back to the point by restating it, frustrating as that may be, but don't ignore legitimate responses which are logically related.
There are vast differences in opinion on what is logically related though, so allow for some different views before you declare something off-topic or derailing.

 

[gerrycan]

This is an open live forum isn't it? What would the difference be?
Why do you think this is not a fair and level playing field?
Thread drift happens organically as different posters interact, it's not deliberate derailing. Saying it's allowed to happen because people can't handle their minds being blown by your truth is also adding to the derailing.

You can always get it back to the point by restating it, frustrating as that may be, but don't ignore legitimate responses which are logically related.
There are vast differences in opinion on what is logically related though, so allow for some different views before you declare something off-topic or derailing.

ok, i will ignore those who seek to derail the topic, but that will not stop them doing it. It was a fair forum, until it became clear that NIST HAD omitted elements and made serious errors. The point has been restated, I came here to debate the truth, not to score points. Mick has been on topic in the main and i commend that, but my response to the obvious attempts to derail this will be to debate it elsewhere regardless.

 

[gerrycan]

But I was responding to you asking me "what would have happened if the girder at C44-79 had not failed and continued to provide lateral support to the column."

And what would have happened is that the column could not have buckled. Therefor the question is whether the girder could have failed in the manner that NIST claim it did. Your own checking of the expansion rates in the beams says that NIST are wrong.

 

[Mick West]

Sheer studs in other buildings discussion moved to:
https://www.metabunk.org/threads/wtc7-and-other-buildings-the-significance-of-sheer-studs.2510/

 

[gerrycan]

I think kawika got to the heart of the matter in #500. This requires a response.

 

[Mick West]

And what would have happened is that the column could not have buckled. Therefor the question is whether the girder could have failed in the manner that NIST claim it did. Your own checking of the expansion rates in the beams says that NIST are wrong.

I'd agree it seems unlikely it could have simply fallen off the seat to the west.

But I'd disagree that's what NIST are claiming. I think that's the mistaken impression they give in summaries. But really what they said happened is the floor system collapsed because of multiple failures of many elements due to fire.

 

[Mick West]

I think kawika got to the heart of the matter in #500. This requires a response.

Which bit?

 

[gerrycan]

Which bit?

All of it, but specifically the fact that the model uses 4 hours and the report says that the fires lasted 15 minutes. This is why it is not realistic for you to revert to using hypothetical model data to argue against reality.

 

[Mick West]

All of it, but specifically the fact that the model uses 4 hours and the report says that the fires lasted 15 minutes. This is why it is not realistic for you to revert to using hypothetical model data to argue against reality.

Isn't the 4 hours covering the fires moving from place to place? You know WTC7 didn't just burn for 15 minutes.

Are you just arguing now that any model is irrelevant?

 

[gerrycan]

The model is not realistic. And you have no input data to check what they did so it is meaningless and not verifiable. What you have been presented with has drawings, engineering calculations and evidence to back it up, You cannot counter that with a cartoon for which there is no data. All you have is a guess at what they did. You have empirical data to check my claims. Let's be fair, truthful and scientific about this.

 

[Hitstirrer]

This is an open live forum isn't it? What would the difference be?
Why do you think this is not a fair and level playing field?
Thread drift happens organically as different posters interact, it's not deliberate derailing. Saying it's allowed to happen because people can't handle their minds being blown by your truth is also adding to the derailing.

You can always get it back to the point by restating it, frustrating as that may be, but don't ignore legitimate responses which are logically related.
There are vast differences in opinion on what is logically related though, so allow for some different views before you declare something off-topic or derailing.

The point has been made many times.

NIST printed in their final report that a girder was pushed by thermal expansion of attached beams, westwards, from its seat, causing floor 13 to drop onto 12 and so on down to 5. That allowed column 79 to buckle as it was laterally unsupported over many floors. And that caused global collapse.

The thread drifts because people refuse to accept the words in NISTs report and insert their own theory about how this event occured.

If a focus on gerry's new information concerning stiffener plates could be maintained perhaps some progress could be made. Until the scientific method is employed by examining his claim, to independently verify the existence of stiffeners, then it would help. Then, if the effect of those stiffeners on the NIST claim of walk-off was independently researched by consulting qualified engineers, another step forward would have been made. NISTs calculations of distances capable of being 'pushed' should be independantly checked in order to verify them.

Continually casting around saying that much was going on and that the fires were affecting many components does not debunk the basic claim.

And after all, it was NIST who specifically nailed it down to that girder and its connection. What is the value in ignoring their words and hinting that they shouldnt have been so simplistic ? They were. And they DID say that. That is why their words are now under this scrutiny.

Eventually, if such a scientific method was taken in order to debunk gerry's claim, and then proof to support the debunk was obtained and itself checked, then a real debunk would have taken place.

Until then the evidence provided by gerry stands un-debunked.

 

[Mick West]

The point has been made many times.

NIST printed in their final report that a girder was pushed by thermal expansion of attached beams, westwards, from its seat, causing floor 13 to drop onto 12 and so on down to 5. That allowed column 79 to buckle as it was laterally unsupported over many floors. And that caused global collapse.

The thread drifts because people refuse to accept the words in NISTs report and insert their own theory about how this event occured.

Not my own theory, just the more detailed version of NIST's theory. You paraphrase this paragraph from NCSTAR 1-9, probable collapse sequence:

Initial Local Failure for Collapse Initiation. The simple shear connection between Column 79
and the girder that spanned the distance to the north face (to Column 44) failed on Floor 13. The
connection failed due to shearing of erection bolts, caused by lateral thermal expansion of floor
beams supporting the northeast floor system and, to a lesser extent, by the thermal expansion of
the girder connecting Columns 79 and 44. Further thermal expansion of the floor beams pushed
the girder off its seat, which led to the failure of the floor system surrounding Column 79 on
Floor 13. The collapse of Floor 13 onto the floors below—some of which were already
weakened by fires—triggered a cascade of floor failures in the northeast region. This, in turn, led
to loss of lateral support to Column 79 in the east-west direction over nine stories (between Floors
5 and 14). The increase in unsupported length led to the buckling failure of Column 79, which
was the collapse initiation event.

And yet this "led to", implying "caused" does not seem to match anything else in the report. It does not match the initial LSDYNA simulation, where the beams pulled the girder off as they buckled. It does not match the 47 floor LSDYNA simulation, where the floor collapse is seen as being initiated in several places, and the girder hardly moves in the initial part.

Initial Local Failure for Collapse Initiation
The global collapse analysis calculated a sequence of events that resulted in the buckling of critical
Column 79.

The floor framing structure was thermally weakened at Floors 8 to 14, with the most substantial fire induced
damage occurring in the east region of Floors 12, 13, and 14. Even though each floor had been
weakened over hours of exposure to separate and independent fires, it was not until there was substantial
damage to the long span floors in the northeast region of Floor 13 that the initial failure event, i.e.,
buckling of Column 79, was triggered.

After the fire-induced ANSYS damage was applied, floor sections surrounding Columns 79 to 81 on
Floors 13 and 14 collapsed to the floors below, as shown in Figure 12–42. The LS-DYNA analysis
calculated the dynamic response of the structure to the floor failures and resulting debris impact loads on
the surrounding structure. The thermally weakened floors below Floors 13 and 14 could not withstand
the impact from the collapsing floors, resulting in sequential floor collapses. The floor systems
progressively failed down to Floor 5, where the debris accumulated, as shown in Figure 12–43.

So my opinion is that in order to reconcile these two accounts, "led to" should really be read as "was followed by". I think some people within NIST placed too much emphasis on this girder because it was part of their initial hypothesis, and their initial focus.

 

[gerrycan]

Not my own theory, just the more detailed version of NIST's theory. You paraphrase this paragraph from NCSTAR 1-9, probable collapse sequence:......

Again you are using something for which you have no data. That's just not scientific Mick, and you know it. Regardless, what we do know is that because of the element target sizes in LSDYNA and ANSYS being 0.15 and 0.3M NIST claim that they were unable to accurately model the connection details at columns 79 and 81 in either model. This is of course pure fantasy on NISTs part because either program is capable of modelling these elements, but it does make your continued references to models for which you have no data, and that are not accurate for the connections that we are discussing, TOTALLY IRRELEVANT to this debate. You need to counter like with like. You have been presented with empirical evidence, you need to counter it with same. You are unable to do so, and to continue to peddle cartoons that you have no data for is not helping your case or adding to your credibility in any way shape or form.

 

[Hitstirrer]

Mick.

quote :- " So my opinion is that in order to reconcile these two accounts, "led to" should really be read as "was followed by". I think some people within NIST placed too much emphasis on this girder because it was part of their initial hypothesis, and their initial focus."

You really arn't allowed to re-write NIST's report to attain a debunk you know.

Bad form that.

 

[gerrycan]

How could they "fail the girder" and THEN push it off its seat?
Edit: oh, you mean this slide from the tech briefing:

Yes, I did, and you were willing to take me to task for that statement (if it had been mine) I bet. But you went strangely silent when you realised that NIST actually said it and not me.

I think I am all about truth and science

#372
I actually think you probably are, but NIST are not and you feel betrayed now that you realise that they do not share your ideals, and justifiably so. It is time to walk the walk Mick. You are unable to debunk my claim, you need to admit this. It is no shame on your part, NIST have not, and cannot provide you the evidence to do so. Walk the walk.