Critical Errors and Omissions in WTC7 Report Uncovered

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gerrycan

Banned
Banned
NIST prefer Mick prefers to ignore the real initiating event of that girder dropping by writing that the initiating event was column 79 buckling. That isnt science. To ignore the simple cause/effect process and jump straight to the effect as the cause is junk science.

Thanks hitstirrer, saved me some typing.
 

Mick West

Administrator
Staff member
NO.
From NIST Technical Briefing on its Final Draft Report on WTC 7
"And the main reason the girder can be pushed off to the west is there is no opposing beam on this side trying to push it back to the east, because of the
arrangement of the floor framing system. And, as you see in the sketch on your slides, you will see that once the bolts break, then you have essentially the girder moves off the seat and eventually falls." ~ Shyam Sunder, NIST lead investigator.


So do we now agree on this Mick?

"Eventually falls". I'd agree with that. But the question here is what is the initiating event for the building collapse? Your video seems to show that girder did not have much to do with it.

NIST says the initiating event was the buckling of column 79. They list a great many things leading up to that, but basically the collapse of the floors around it. Now going by just the written report, and the simulations, what made the floors collapse?

I must admit here I had assumed it was the 79-44 girder falling, and I thought that was the initiating event. But upon reading the relevant sections of the report in depth, and viewing your helpfully highlighted video, that really does not seem to be the case. Working backwards from the actual initiating event (C79 buckling), we have the "Initial Local Failure", which is:

1-9 572 (pdf 638).

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 fireinduced
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.
Content from External Source
What was the ANSYS damage?
1-9 505 (pdf 571)

Summary. After 4.0 h of heating, Columns 79, 80, and 81 had lost lateral support in the north-south
direction at Floor 13, due to failure of the girders between the columns. The girders between Columns 80
and 81 had buckled and the girders between Columns 79 and 44 and Columns 26 and 81 had walked off
the bearing seat at Column 79 and 81, respectively. In addition, all of the bolts had sheared at Column 79
on Floor 14, and two to three bolts had sheared on Floor 12. Approximately one-half to three-quarters of
the east floor beams had a connection damage index of 0.75-0.99 on Floors 11, 12, and 14 and all of the
east floor beams had failed on Floor 13. After 4.0 h of heating, there was substantially more damage and
failures in the WTC 7 structural system than after 3.5 h of heating. Columns 79, 80, and 81 had lost
lateral support at one or more floors.

The impact of a floor section falling on the floor below was not analyzed in the 16 story ANSYS model,
but was simulated in the 47 story LS-DYNA model (Chapter 12).
Content from External Source
Perhaps I'm missing something here? But the eventual falling of the girder seems like a consequence of the flooring system collapse, and not the cause.
 

Hitstirrer

Active Member
You see Mick. There is the problem in a nutshell.

Your quote - " Working backwards from the actual initiating event (C79 buckling), we have the "Initial Local Failure", which is:"

You have fallen into 'NISTspeak' there.

How can a scientific report work backwards and then claim that a later event was the actual 'initiation' ?

Its almost Orwells newspeak.

You really do need to break free from that kind of thinking.
 

Mick West

Administrator
Staff member
Based on your highlighted video, here's G79-44 in the NIST report rendering:
 
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Mick West

Administrator
Staff member
You see Mick. There is the problem in a nutshell.

Your quote - " Working backwards from the actual initiating event (C79 buckling), we have the "Initial Local Failure", which is:"

You have fallen into 'NISTspeak' there.

How can a scientific report work backwards and then claim that a later event was the actual 'initiation' ?

Its almost Orwells newspeak.

You really do need to break free from that kind of thinking.

I'm simply going back though the text the see what they wrote. It works exactly the same forward.
 

Hitstirrer

Active Member
I'm simply going back though the text the see what they wrote. It works exactly the same forward.

Wow. Your getting really good at Orwell newspeak now. I will need to consider that reply very carefully because at first sight it is gibberish.
 

Hitstirrer

Active Member
I'm simply going back though the text the see what they wrote. It works exactly the same forward.

OK - Ive considered it. Really. If you are capable of accepting that NIST claims that the initiating event was 79 buckling, without also accepting that such buckling could not take place without a prior err initiating event then I fear that we are done here.
 

Mick West

Administrator
Staff member
Wow. Your getting really good at Orwell newspeak now. I will need to consider that reply very carefully because at first sight it is gibberish.

  • My goal was to see what NIST said caused the collapse.
  • So I looked through the document for "initiating event"
  • I found that they said the initiating event was the buckling of C79
  • Hence I had to find what they said caused C79 to buckle
  • Logic dictated this would be earlier in the document.
  • Hence I "worked backwards" from that point.
 

kawika

New Member
Thank you kawika. That information is exactly what I hinted to Mick earlier about. Your comments mirror my own analysis of the simulations released by NIST.


See Page 575, pdf 641. The support is accounted for.
Red circles designate NO SUPPORT. Yet another NIST contradiction in our faces.

No support, but yes, it does have support in the north direction. "Lateral restraint in north only" is the massive N/E region floor systems over five levels. Those floor systems to the north AND east cover approximately 2300 square feet each level. The concrete floor is tied to the wind girders between the exterior columns and the beams are directly tied to six exterior columns. Additionally, one beam (G3005) and two beam stubs are tied to wind girders.

NIST said there was no lateral support over nine levels.
 
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Hitstirrer

Active Member
  • My goal was to see what NIST said caused the collapse.
  • So I looked through the document for "initiating event"
  • I found that they said the initiating event was the buckling of C79
  • Hence I had to find what they said caused C79 to buckle
  • Logic dictated this would be earlier in the document.
  • Hence I "worked backwards" from that point.

And you don't find any conflict over an 'initiating event' that requires a prior 'initiating event' in order to become a secondary 'initiating event' ? This is becoming bizarre.
 

Mick West

Administrator
Staff member
OK - Ive considered it. Really. If you are capable of accepting that NIST claims that the initiating event was 79 buckling, without also accepting that such buckling could not take place without a prior err initiating event then I fear that we are done here.

Erm, No. I just mistakenly thought that NIST referred to the unseating as THE initiating event. But they don't

They refer to the collapse of the floors around cols 79-81 as the Initial Local Failure.

They don't refer to the falling of G44-79 as anything in particular.
 

Mick West

Administrator
Staff member
And you don't find any conflict over an 'initiating event' that requires a prior 'initiating event' in order to become a secondary 'initiating event' ? This is becoming bizarre.

I think we are having a problem with the terminology. Let's focus instead on what NIST claimed actually happened.
 

Mick West

Administrator
Staff member
Another quote from the NIST team:

Red circles designate NO SUPPORT. Yet another NIST contradiction in our faces.

No support, but yes, it does have support in the north direction. "Lateral restraint in north only" is the massive N/E region floor systems over five levels. Those floor systems cover approximately 2300 square feet each level. The concrete floor is tied to the wind girders between the exterior columns and the beams are directly tied to six exterior columns. Additionally, one beam and two beam stubs (G3005) are tied to wind girders.

NIST said there was no lateral support over nine levels.

No, there was just support to the north, and the beam buckled to the east. There was no east/west support.

But this a a bit off-topic. The issue is if the stiffener plates are significant. I can't see how they are, after watching the highlighted video and reading the relevant sections of NCSTAR 1-9.
 

Hitstirrer

Active Member
I think we are having a problem with the terminology. Let's focus instead on what NIST claimed actually happened.

We sure are.

NIST prefer to use terms like 'initial local failure' to obscure the actual event that really initiated the global collapse. It fits their overall story much better to point to a larger 'column buckling' event and hope that people will nod wisely and say - ah yes - its clear to me now. If that column 79 buckled it was sure to bring down that entire area. The smoke n mirrors then prevents them from asking " but what allowed 79 to buckle? Wasn't it restrained over many floors?

In that way they can divert attention away from the fully documented 'real' initiation event that allowed 79 to buckle. But gerry followed the scientific method and checked their attempt to move the event forwards by claiming the buckling to be the initiation.

He simply went back to the real initiation event despite NIST saying it was just a 'local failure'. As I said. Cause/Effect. Don't forget that NIST many times said that the girder spanning 79 to 44 dropping from its seat was the very first failure event.

So Mick - you see what has happened here?

You have fallen in that trap. Your quote :- " Erm, No. I just mistakenly thought that NIST referred to the unseating as THE initiating event. But they don't" is telling.

You wern't mistaken at all. They deliberately avoided saying that the unseating was the initiation. Why can't you see that ?
 

Jazzy

Closed Account
NIST concludes by saying that one girder on floor 13 dropped onto floor 12 and that went on to cause global collapse. That is their simple claim. Its not me being simplistic - its NIST.

Just for reference, relevant portions of the NIST Report on the collapse of WTC 7.
NIST REPORT ES.3.
..... thermal expansion occurring at temperatures hundreds of degrees below those typically considered in design practice for establishing structural fire resistance ratings; significant magnification of thermal expansion effects due to the long-span floors, which are common in office buildings in widespread use; connections that were designed to resist gravity loads, but not thermally induced lateral loads; and a structural system that was not designed to prevent fire-induced progressive collapse. Even without the structural damage, WTC 7 would have collapsed from fires having the same characteristics as those experienced on that day.
2.3. Page 19
..... Fires broke out on at least 10 floors of WTC 7 ..... All of these fires reached the northeast sector of the building between approximately 3:00 p.m. and 4:00 p.m. The intensities of the fires on the 11th, 12th, and 13th floors were higher than those on the 7th, 8th, and 9th floors because of the higher loading of combustibles and a larger burning area. There was also a small fire on the north side of the vacant 14th floor shortly before the collapse of the building.
12th Floor
The fire on the 12th floor followed a path similar to that of the fire on the 11th floor, but with different timing. Fire was first seen on the 12th floor at 2:08 p.m., toward the south end of the east face. Further south on this face, the window glass was still intact, indicating that this fire had burned in the building interior as it turned the southeast corner. By around 2:30 p.m., the visible flames had diminished, but the fire had spread both south into the southeast corner and north, reaching two-thirds of the way to the northeast corner. By 3:00 p.m., the fire had spread internally past the northeast corner and onto the north face. In less than 15 min, the fire simultaneously spread rapidly to the east to engulf the northeast corner of the floor and more slowly westward about one-third of the way across the north face. The fire continued spreading westward in starts and stops, approaching the northwest corner of the floor around 3:45 p.m. At around 5:00 p.m., the fire had reached the northwest corner.
13th Floor
Like the fires on the 11th and 12th floors, fire on the 13th floor also moved counterclockwise. Fire was seen at about 2:30 p.m. on the east side of the floor. Somewhat later, smoke and flames were coming from windows across much of the east face. Around 3:41 p.m., the fire had turned the northeast corner and was one-fourth of the way across the north face. Soon after 4:00 p.m., flames had reached at least to the midpoint of the north face; and at 4:38 p.m., the fires to the east had died down to the point where they could no longer be observed. Around 5:00 p.m., there was intense burning to the west of the center of the north face. A couple of minutes prior to the collapse of the building at 5:20:52 p.m., flames jetted from windows in the same area, indicating that there had been fire toward the interior of the floor.
2.4 THE PROBABLE COLLAPSE SEQUENCE
The following is the NIST account of how the fires in WTC 7 most likely led to the building's collapse.
The collapse of WTC 1 damaged seven exterior columns, between Floors 7 and 17 of the south and west faces of WTC 7. It also ignited fires on at least 10 floors between Floors 7 and 30, and the fires burned out of control on Floors 7 to 9 and 11 to 13. Fires on these six floors grew and spread since they were not extinguished either by the automatic sprinkler system or by FDNY, because water was not available in WTC 7. Fires were generally concentrated on the east and north sides of the northeast region beginning at about 3 p.m. to 4 p.m.
As the fires progressed, some of the structural steel began to heat. According to the generally accepted test standard, ASTM E-119, one of the criteria for establishing the fire resistance rating for a steel column or floor beam is derived from the time at which, during a standard fire exposure, the average column temperature exceeds 538 °C (1000 °F) or the average floor beam temperature exceeds 593 °C (1100 °F). These are temperatures at which there is significant loss of steel strength and stiffness. Due to the effectiveness of the SFRM, the highest column temperatures in WTC 7 only reached an estimated 300 °C (570 °F), and only on the east side of the building did the floor beams reach or exceed about 600 °C (1100 °F). The heat from these uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, primarily at or below 400 deg C (750 deg F), damaging the floor framing on multiple floors.
The initiating local failure that began the probable WTC 7 collapse sequence was the buckling of Column 79. This buckling arose from a process that occurred at temperatures at or below approximately 400 °C (750 °F), which are well below the temperatures considered in current practice for determining fire resistance ratings associated with significant loss of steel strength. When steel (or any other metal) is heated, it expands. If thermal expansion in steel beams is resisted by columns or other steel members, forces develop in the structural members that can result in buckling of beams or failures of connections.
Fire-induced thermal expansion of the floor system surrounding Column 79 led to the collapse of Floor 13, which triggered a cascade of floor failures. In this case, the floor beams on the east side of the building expanded enough that they pushed the girder spanning between Columns 79 and 44 to the west on the 13th floor. (See Figure 1–5 for column numbering and the locations of girders and beams.) This movement was enough for the girder to walk off of its support at 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 (which, as noted in Section 1.2.3, was much thicker and stronger). Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This left Column 79 with insufficient lateral support, and as a consequence, the column buckled eastward, becoming the initial local failure for collapse initiation.
Content from External Source
I am very well aware that the interaction of all elements in and around this suggested failure point would be very complex. But as NIST has reduced it to a simplistic single connection failure i feel able to be equally simplistic in looking closely at that simplistic claim. NIST did not say that the interaction was so complex that it was impossible to be specific. They were specific. And in doing so allow me to challenge that simplistic conclusion.
Jazzy said:
Figure 2–2. Eastward buckling of Column 79, viewed from the southeast.
Due to the buckling of Column 79 between Floors 5 and 14, the upper section of Column 79 began to descend. The downward movement of Column 79 led to the observed kink in the east penthouse, and its subsequent descent. The cascading failures of the lower floors surrounding Column 79 led to increased unsupported length in, falling debris impact on, and loads being re-distributed to adjacent columns; and Column 80 and then Column 81 buckled as well. All the floor connections to these three columns, as well as to the exterior columns, failed, and the floors fell on the east side of the building. The exterior façade on the east quarter of the building was just a hollow shell.
The failure of the interior columns then proceeded toward the west. Truss 2 (Figure 1–6) failed, hit by the debris from the falling floors. This caused Column 77 and Column 78 to fail, followed shortly by Column 76. Each north-south line of three core columns then buckled in succession from east to west, due to loss of lateral support from floor system failures, to the forces exerted by falling debris, which tended to push the columns westward, and to the loads redistributed to them from the buckled columns. Within seconds, the entire building core was buckling.
The global collapse of WTC 7 was underway.

The shell of exterior columns buckled between the 7th and 14th floors, as loads were redistributed to these columns due to the downward movement of the building core and the floors. The entire building above the buckled-column region then moved downward as a single unit, completing the global collapse sequence.
.



Content from External Source
I can't see where NIST was being "simplistic".

Nor does the above look like "symmetry".

Mind you, the previously undamaged external faces, they looked symmetrical, a moment before they buckled and fell.
 
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Hitstirrer

Active Member
Here is a relevent paragraph from that latest War and Peace entry from Jazzy.

" Fire-induced thermal expansion of the floor system surrounding Column 79 led to the collapse of Floor 13, which triggered a cascade of floor failures. In this case, the floor beams on the east side of the building expanded enough that they pushed the girder spanning between Columns 79 and 44 to the west on the 13th floor. (See Figure 1–5 for column numbering and the locations of girders and beams.) This movement was enough for the girder to walk off of its support at Column 79."

Any further questions about the real initiating event ?
 

gerrycan

Banned
Banned
Mick, this is getting ridiculous. You have done well in this thread and have been probably one of the the fairest debunkers I have debated. We disagree totally on the issue but you have my respect, but that is slipping with what looks like a change in tone toward avoidance and denial of the obvious. Would you like me to post a list of where you have done this in the thread so far?
 

Mick West

Administrator
Staff member
You wern't mistaken at all. They deliberately avoided saying that the unseating was the initiation. Why can't you see that ?

I can ses they deliberately did not, but gerrys argument seem to hinge upon them saying that it was. If it wasn't, then gerry has no real argument here.
 

gerrycan

Banned
Banned
I can ses they deliberately did not, but gerrys argument seem to hinge upon them saying that it was. If it wasn't, then gerry has no real argument here.
Total denial,
Here's a selection of what you have stated on this thread so far Mick -

First Mick doubted that there were studs on the beams.....see post #62 - he corrected this.
Then he doubted their function....#87 - "Can you actually stop steel expanding by holding it in place?"
He then sought out drawing S-8-10 and continued to assert that the BEAMS had no studs. (various posts)
Later, he admitted the studs, and asked "would they make a mechanical difference?" post #129
Claimed that verinage would work on a steel framed building in pist #131
He asked on Sep10th how much i thought the beam would expand, I answered the same day and gave him the figures.
#176 Stated that "640.69*.00000701*1040 = 4.67, but like I said, NIST never claims a longer expansion"
#181 I showed him where NIST claimed expansion of "at least 5.5inches"
#229 Tries to argue against ae911truth instead of me "This seems to be the crux of the AE911 argument"
#237 Dislikes me focussing on details "You seem to like focussing on details (like the stiffener plates, and the 11 vs. 12 inch seat, and the temperature, and the thermal expansion coefficients of steel)"
#259 Tries to discard the whole topic of the thread "Why do you need to get the initiating event right? "
#265 Claims I am..."linking two separate things. The initiating event was just what eventually caused C79 to buckle by itself"
#267 Begins to invent new initiating events "The initiating event was likely something similar"
#272 Further avoids the specific event claimed by NIST "It could be this, or something similar, or something else. "
#274 Says "It would certainly be helpful" to find out what the initiating event was.
#325 Continues earlier character assasination of TS "More and more people like Tony Szamboti, who were already convinced the NIST analysis was rigged"
#329 Uses screenshots from my video and then claims in #356 to have done them himself "I roughly based it on"
#329 Claims that collapse preceded initiating event "And that's not even accounting for the other damage that was going, possible other falling beams. Other failed or failing connections"
#332 Tries to ignore elements and calls NISTs initiating event hypothetical "It's your hinging of everything on the stiffener plates in the hypothetical initiating event that's an oversimplification"
#335 Claims NIST did not state that "This is exactly what happened down to the last inch!!!"
#342 Asserts that the structural drawings that I and NIST used are not correct " a possible omission of stiffener plates"
#345 Tries to skip past the initiating event "Do you doubt that column 79 buckled?"
#352 Huge blind assertion "You don't invalidate the entire thing by adding a stiffener plate"
#364 Further denial of drawings and NISTs statements "You are just pointing out a possible inaccuracy in this one hypothetical event"
#370 Hedges his bets on the initiating event "I'm not at all convinced that the Col79 unseating is not the initiating event"
#376 Ignores who mentioned Tony in this thread first be ommiting to refer to his earlier post which said "Tony seems like he would be a little predisposed to make such an assessment"
#396 Still denies NISTs initiating event "Would you agree that NIST don't actually refer to the unseating of the girder as the initiating event"
 

Mick West

Administrator
Staff member
Mick, this is getting ridiculous. You have done well in this thread and have been probably one of the the fairest debunkers I have debated. We disagree totally on the issue but you have my respect, but that is slipping with what looks like a change in tone toward avoidance and denial of the obvious. Would you like me to post a list of where you have done this in the thread so far?

I totally admit I've changed my position, but that's because I got new information. I was working under the assumption that the girder falling was the initiating event. I have since discovered - in large part thanks to your video with the highlight - that it was not.

Back at the start you said:

We examined the claim by NIST and others that the failure of a girder at column 79 initiated the collapse and found that their story made no sense when we compared the connection they described to the connection stated in the structural drawings.

But it turns out that NIST never actually claimed that, and their simulation does not show that.

It's been a bit of a misunderstanding. I feel like I understand it a lot better now.
 

gerrycan

Banned
Banned
I totally admit I've changed my position, but that's because I got new information. I was working under the assumption that the girder falling was the initiating event. I have since discovered - in large part thanks to your video with the highlight - that it was not.

Back at the start you said:



But it turns out that NIST never actually claimed that, and their simulation does not show that.

It's been a bit of a misunderstanding. I feel like I understand it a lot better now.
NIST claimed that the girder failed due to thermal expansion of long span beams to the east of it. How many times does this need to be stated??
 

Mick West

Administrator
Staff member
Total denial,
Here's a selection of what you have stated on this thread so far Mick -

First Mick doubted that there were studs on the beams.....see post #62 - he corrected this.
Then he doubted their function....#87 - "Can you actually stop steel expanding by holding it in place?"
He then sought out drawing S-8-10 and continued to assert that the BEAMS had no studs. (various posts)
Later, he admitted the studs, and asked "would they make a mechanical difference?" post #129
Claimed that verinage would work on a steel framed building in pist #131
He asked on Sep10th how much i thought the beam would expand, I answered the same day and gave him the figures.
#176 Stated that "640.69*.00000701*1040 = 4.67, but like I said, NIST never claims a longer expansion"
#181 I showed him where NIST claimed expansion of "at least 5.5inches"
#229 Tries to argue against ae911truth instead of me "This seems to be the crux of the AE911 argument"
#237 Dislikes me focussing on details "You seem to like focussing on details (like the stiffener plates, and the 11 vs. 12 inch seat, and the temperature, and the thermal expansion coefficients of steel)"
#259 Tries to discard the whole topic of the thread "Why do you need to get the initiating event right? "
#265 Claims I am..."linking two separate things. The initiating event was just what eventually caused C79 to buckle by itself"
#267 Begins to invent new initiating events "The initiating event was likely something similar"
#272 Further avoids the specific event claimed by NIST "It could be this, or something similar, or something else. "
#274 Says "It would certainly be helpful" to find out what the initiating event was.
#325 Continues earlier character assasination of TS "More and more people like Tony Szamboti, who were already convinced the NIST analysis was rigged"
#329 Uses screenshots from my video and then claims in #356 to have done them himself "I roughly based it on"
#329 Claims that collapse preceded initiating event "And that's not even accounting for the other damage that was going, possible other falling beams. Other failed or failing connections"
#332 Tries to ignore elements and calls NISTs initiating event hypothetical "It's your hinging of everything on the stiffener plates in the hypothetical initiating event that's an oversimplification"
#335 Claims NIST did not state that "This is exactly what happened down to the last inch!!!"
#342 Asserts that the structural drawings that I and NIST used are not correct " a possible omission of stiffener plates"
#345 Tries to skip past the initiating event "Do you doubt that column 79 buckled?"
#352 Huge blind assertion "You don't invalidate the entire thing by adding a stiffener plate"
#364 Further denial of drawings and NISTs statements "You are just pointing out a possible inaccuracy in this one hypothetical event"
#370 Hedges his bets on the initiating event "I'm not at all convinced that the Col79 unseating is not the initiating event"
#376 Ignores who mentioned Tony in this thread first be ommiting to refer to his earlier post which said "Tony seems like he would be a little predisposed to make such an assessment"
#396 Still denies NISTs initiating event "Would you agree that NIST don't actually refer to the unseating of the girder as the initiating event"

Yes, it's been a great learning experience!

Now, what about this claim of yours that NIST says the falling girder caused the collapse? Don't you think they would have noticed that it didn't fall much in the simulation? That the main cause of the collapse seemed to be the floor connected to the 81-80 and 80-79 girders?
 

Mick West

Administrator
Staff member
NIST claimed that the girder failed due to thermal expansion of long span beams to the east of it. How many times does this need to be stated??

Failed, but did not fall and trigger the collapse. Lots of girders, beams, connections, and floors failed.
 

gerrycan

Banned
Banned
Yes, it's been a great learning experience!

Now, what about this claim of yours that NIST says the falling girder caused the collapse? Don't you think they would have noticed that it didn't fall much in the simulation? That the main cause of the collapse seemed to be the floor connected to the 81-80 and 80-79 girders?
I appreciate the learning curve that this has presented you with. It's not an easy topic to debate and you really do have my respect for the way you have conducted yourself. The problem is, that you seem to be still denying what the videos are claiming. Do I have it wrong, or are you actually admitting that the videos are in fact correct?
 

Jazzy

Closed Account
They deliberately avoided saying that the unseating was the initiation.
What they said was
"The floor beams on the east side of the building expanded enough that they pushed the girder spanning between Columns 79 and 44 to the west on the 13th floor. This movement was enough for the girder to walk off of its support at Column 79".
Content from External Source
That seems reasonable to me. Given the state that girder was in, it's hardly surprising it "walked off".

What they did not say was expansion of that girder alone was responsible for the floor falling, which was Gerry's whole argument..
 
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Hitstirrer

Active Member
I can ses they deliberately did not, but gerrys argument seem to hinge upon them saying that it was. If it wasn't, then gerry has no real argument here.

Well all I can do then is point to NIST's own words. See my post #416.

As they say in Rome. QED !
 

Mick West

Administrator
Staff member
I appreciate the learning curve that this has presented you with. It's not an easy topic to debate and you really do have my respect for the way you have conducted yourself. The problem is, that you seem to be still denying what the videos are claiming. Do I have it wrong, or are you actually admitting that the videos are in fact correct?

The claim that they omitting the stiffening plate is quite possibly correct. The significance is not.

From this video you posted, verified by matching it with the diagram in NCSTAR 1-9 , it's quite clear the stiffener plates would have no effect at all, the beam fell after the floors started to collapse. It moved mostly axially off the seat.


 

Attachments

  • Tracking WTC7 Girder C44-79 at Floor 13.mp4
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Hitstirrer

Active Member
What they said was
"The floor beams on the east side of the building expanded enough that they pushed the girder spanning between Columns 79 and 44 to the west on the 13th floor. This movement was enough for the girder to walk off of its support at Column 79".
Content from External Source
What they said seems reasonable to me. Given the shape of the girder it's hardly surprising it "walked off".

What they did not say was expansion of that girder alone was responsible for the floor falling, which was Gerry's whole argument..

What exactly do you imagine was holding that floor up?

And what 'shape' do you now imagine the girder had aquired in order to make is hardly surprising to you that it 'walked off' ?

I am beginning to think that Iv'e stumbled into an Alice in Wonderland sketch the more this thread develops.
 

Mick West

Administrator
Staff member
What exactly do you imagine was holding that floor up?

And what 'shape' do you now imagine the girder had aquired in order to make is hardly surprising to you that it 'walked off' ?

I am beginning to think that Iv'e stumbled into an Alice in Wonderland sketch the more this thread develops.

See video above.
 

kawika

New Member
They are on the construction diagram, as well as I understand it. So it seems likely they were on the girder.

Would you agree that NIST don't actually refer to the unseating of the girder as the initiating event?

See NCSTAR 1-9, (NOV 2008), Page 611, PDF page 677, Item #11. Initial Local Failure for Collapse Initiation

NIST describes many events before they decide to call the buckling of column 79 the "collapse initiating event" because they tie everything to the PH collapse, which is the only event that can actually be seen. Their collapse starts when the exterior view says it does.

But come on, they are reporting over and over that huge interior collapses are going on well before this point. So let's not quibble. The initiating event could be when the fire started, that led to the thermal expansion, that led to the bolts shearing, that led to the girder being pushed westwards. How far away from the PH falling or the column buckling can we go to satisfy the term "initiating"?

If you study the report, you'll read that the A2001 girder on F13 was the first failure of vertical support. Floor cascades after that meant many other girders, beams and floors were failing. Then C79 reaches a condition of no lateral support over nine floors.

If you study the simulations you'll see that it is not just F13 that fails. The narrative does not follow the SIM. I'd like to understand how the writing and SIM teams end up telling different stories, when the computer modeling/SIM team was the one charged with figuring out the probable sequence of events.
 

Mick West

Administrator
Staff member
See NCSTAR 1-9, (NOV 2008), Page 611, PDF page 677, Item #11. Initial Local Failure for Collapse Initiation

NIST describes many events before they decide to call the buckling of column 79 the "collapse initiating event" because they tie everything to the PH collapse, which is the only event that can actually be seen. Their collapse starts when the exterior view says it does.

But come on, they are reporting over and over that huge interior collapses are going on well before this point. So let's not quibble. The initiating event could be when the fire started, that led to the thermal expansion, that led to the bolts shearing, that led to the girder being pushed westwards. How far away from the PH falling or the column buckling can we go to satisfy the term "initiating"?

Let's leave the terminology to lexologists, and focus on what NIST claims happened, and if the stiffener plates would have an effect.

If you study the report, you'll read that the A2001 girder on F13 was the first failure of vertical support. Floor cascades after that meant many other girders, beams and floors were failing. Then C79 reaches a condition of no lateral support over nine floors.

If you study the simulations you'll see that it is not just F13 that fails. The narrative does not follow the SIM. I'd like to understand how the writing and SIM teams end up telling different stories, when the computer modeling/SIM team was the one charged with figuring out the probable sequence of events.

Can you reference that bit of the report?
 

gerrycan

Banned
Banned
Let's leave the terminology to lexologists, and focus on what NIST claims happened, and if the stiffener plates would have an effect.
By the logic now being employed by those who have tried in vain to debunk the contents of the videos, we might as well say that the collapse initiated when the first floor of the building was constructed. It takes fortitude to admit that you were wrong.
 
Perhaps I'm missing something here? But the eventual falling of the girder seems like a consequence of the flooring system collapse, and not the cause.

I think you hit the nail on the head and the problem they are having is because they are coming from the "fire can't make steel fail" school of thought or mindset (I think that is fair to say) so the videos in question were really trying to put forth the notion of "see, fire shouldn't have caused WTC 7 to collapse"

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 fireinduced
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.

What you highlighted in your explanation undermines the real pretext of the 4 part video series playlist which is to give the impression that fires can't cause a building to collapse. The problem for those insisting on that false premise is the vulnerability to fire was not limited to a single point or a single event. As you point out, fire caused multiple structural failures within the building and that point undermines the central notion they want to put forth, I think that is why you are getting such resistance and being accused of being Orwellian. They wanted to give the impression that the whole case about if fire can weaken or did weaknen a structure is dependent on a single event, or specifialy the false impression that the whole case of whether fire weakened the WTC 7 structure to be dependent on a single fluke event which they seek to disprove.

The objective of the videos I think was to push the notion of "see, fires shouldn't have caused the building to collapse" when in fact there were multiple examples of failures on several floors. The thing is even if the specific seat at column 79 didn't fail, it is not like saying there wouldn't have been a collapse because more failure could have occurred since multiple failures had already been occurring.

And that bias against admitting that fire can cause collapse or even local collapse is evident in how the videos talked about WTC 5 because very clearly the video gives the false impression that there were not fire induced failures in WTC 5. It surely doesn't explain that within WTC 5, several floors failed and collapsed due to fire.
 
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Mick West

Administrator
Staff member
By the logic now being employed by those who have tried in vain to debunk the contents of the videos, we might as well say that the collapse initiated when the first floor of the building was constructed. It takes fortitude to admit that you were wrong.

Explain how I'm wrong.
  • NIST does not claim the falling 79-44 girder triggered the collapse
  • NIST's simulation do not show this, as you pointed out
  • Upon the start of the LSDYNA model, floor failure occurred on floor 13 AND 14
  • The LSDYNA model shows floor 14 hitting the floor 13 level while the 79-44 girder is still attached.
  • Hence the stiffener plates are irrelevant. The walk off distance is irrelevant.
What is wrong there?
 

Jazzy

Closed Account
What exactly do you imagine was holding that floor up?
Column 79 - until it didn't.

And what 'shape' do you now imagine the girder had aquired in order to make is hardly surprising to you that it 'walked off'?
No imagination required. Just memory. It's in the thread.

I am beginning to think that Iv'e stumbled into an Alice in Wonderland sketch the more this thread develops.
Lay off the mushrooms and don't just read the nice bits.
 

Mick West

Administrator
Staff member
I think much of the confusion here (including mine) comes from the various levels of detail in the three simulations, and how data was transferred from one the other. Need's more writing than I have time for now, but I encourage people to read it.
 
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gerrycan

Banned
Banned
Explain how I'm wrong.
  • NIST does not claim the falling 79-44 girder triggered the collapse
  • NIST claim that the girder was left unsupported. This alledged lack of support comes from the girders that supported it failing. The girders failure is alleged by them to have come about by thermal expansion, particularly of floor beams to the east of column 79 at floor 13. You are avoiding the issue Mick, and fast losing my respect.
  • NIST's simulation do not show this, as you pointed out
    When did I first mention NISTs simulation, and their simulations do not support what they say themselves let alone anything else. I doubt that they are even a genuine FEA output. As far as their sims go, they admit themselves that they were unable to model the connection around column 79 accurately in them in NCSTAR 1-9A. They are therefor irrelevant.
  • Upon the start of the LSDYNA model, floor failure occurred on floor 13 AND 14
    They were unable to model the connection detail correctly at column 79.
  • The LSDYNA model shows floor 14 hitting the floor 13 level while the 79-44 girder is still attached
    You are merely illustrating just how woeful these models are now. Welcome to the truth movement, and the correct side of this debate.
  • Hence the stiffener plates are irrelevant. The walk off distance is irrelevant.
    Why did Shyam Sunder state that the girder had to walk 5.5 inches if this was not relevant. Why did they release an erratum statement if it wasn't relevant. Do you seriously think that the inclusion of these plates would not affect the distance required. This is getting stupid now.
  • FORCES FROM THERMAL EXPANSION FAILED THE GIRDER AT COLUMN 79, THEN PUSHED THE GIRDER OFF ITS SEAT - NISTslide-32-728.jpg
 

Jazzy

Closed Account
NIST: "The unsupported girder and other local fire-induced damage caused Floor 13 to collapse"
Content from External Source
Gerrycan said:
We examined the claim by NIST and others that the failure of a girder at column 79 initiated the collapse and found that their story made no sense when we compared the connection they described to the connection stated in the structural drawings. They missed out elements, they got dimensions wrong and made mistakes that at best were incompetent, and at worst, dishonest.
My emboldening.

I've made all my comments.
 
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