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Total Building Collapse from a Single Column Failure

gerrycan said:
No, in NISTs simulation the beams were heated to 600. I know it is a pain to do it, but I think it is important to differentiate between the analysis and reality. If NIST say the beam was 600 in their analysis, then that's what it was. Whether it was that temp in reality is more difficult to state with as high degree of accuracy.
Sorry if that sounds like I am nit picking, I don't mean to, but it is crucial to understand that if NIST modeled the seat as 12" and not 11, then the figure of 600c in the beams is not enough to get the push required for the web to move beyond the edge of the seat plate pg in their analysis.
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NIST only used 600°C in their first analysis of the isolated elements around column 79. There was no walk off in that analysis. In the 16 story model and the 47 story model they used the fire simulation inputs for temperature and it was in these models that there was a buckling/walk off failure of that girder.
 
pgimeno said:
I've issues with that.

1) The NIST report states 75-99% damage. That means that not necessarily all bolts were broken. If one bolt remains, the beam is still in place and the girder can easily pivot on it and roll (off).

2) If all bolts failed, the beam would fall to the girder's flange at most. If the connection plates were not too damaged, they would still hold the beam in position horizontally.



I've even quoted the pertinent part. Go look. And that question was not your initial question, by the way.



Well, for one thing, there was a beam on the other side too. The girder was not completely free to move west. That connection was less damaged.

Also, if the beams expanded at different times, one could push while the others held the girder. Of course this possibility means at least one or two would remain in good shape in the end, so ultimately the answer is in NIST's FEA.

But you're contending that their FEA produced the failures they state, on the sole basis that they "omitted structural features" on an unrelated part of the structure. That's reaching.

And you still haven't even begun to address Newton's Bit argument that the connections wouldn't resist the moment anyway, even in their pristine state, I assume.
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It is fascinating that you have no issue believing five out of six 7/8" diameter ASTM A325 bolts broke on each of the five beam connections from the east to girder A2001, but can't identify a reaction force that would have caused it besides the one small beam framing into it from the west. That beam was nearly parallel to the girder and any force it applied insignificant. I would hope you realize that each of those bolts would require about 35,000 lbs to shear at room temperature and about half that (17,500 lbs) even at 600 degrees C. There was no reaction force from the girder side capable of shearing all of those bolts if there were no shear studs on the girder. In addition, the four W24 X 55 beams that did not have lateral support would have buckled before the bolts broke if their shear studs had been broken. But again that would require a reaction force from the girder side and there was none.

Although it is moot because of the above, I thought I would point out that, if all bolts failed and the beams fell onto the top of the bottom flange of the girder then there would be a shortage of expansion as the beams had a 3/4" clearance from the girder web. Now the beams would have to expand 6.25" + .75" = 7.00". You can't get that amount of expansion from 53 foot long steel beams with an 87.5 psf floor load on them at any temperature. It is known that the maximum expansion would have been 5.5".

It seems there is no situation where girder A2001 would have ever come off its seat at column 79. With the discovery of the omitted girder stiffeners and lateral support beams on G3005 and the fact that the seat was actually 12" wide not 11", as NIST originally stated, it really is looking like someone at NIST was just making things up and trying to make it look plausible.
 
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beachnut said:
... idea what the OP is.

When will you post the overwhelming evidence for CD, and close the thread?

What did CTBUH say?
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CTBUH didn't think the girder could have come off its seat at column 79 with stiffeners on it either. If I were you I would be asking myself why the investigators at NIST did not respond to that question.

The bottom line is we now know that the girder could have not come off that seat and it is clear from the discovery that there were serious omissions and a seat width distortion, which happened to match the maximum expansion of the beams to get the girder web past the edge of the seat, that there was some level of malfeasance on the part of someone at NIST to make it look like it could have.

With all that has come out, anyone who still says girder A2001 could have walked off its seat at column 79 is only fooling themselves or trying to fool others.
 
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Tony Szamboti said:
CTBUH didn't think the girder could have come off its seat at column 79 with stiffeners on it either. If I were you I would be asking myself why the investigators at NIST did not respond to that question.

The bottom line is ...
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The bottom line? lol, CTBUH says 911 truth has NO credibility.
The Council would like to make it clear that it sees no credibility whatsoever in the 911 ‘truth movement’ and we believe, with the vast majority of tall building professionals, that all the failures at the WTC (WTC 1, 2, 5, 6 and 7) were a direct or indirect result of the planes that were flown into the two towers. We have carefully looked at the evidence that the 911 ‘truth movement’ presents and we cannot see any credible scientific evidence of a controlled demolition on WTC 7 or any of the other WTC buildings. The Council considers that the ‘truth movement’ is a distraction and should not obfuscate the performance issues which should be at the center of the debate about how best to continue to improve and develop fire and life safety in tall buildings.
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There goes your CD fantasy. Ironic how 911 truth uses sources which say 911 truth is nonsense.

Cool - 13th year of failure for CD. The CD fantasy is nonsense. Your CD claims are a "distraction".
 
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Tony Szamboti said:
CTBUH didn't think the girder could have come off its seat at column 79 with stiffeners on it either. If I were you I would be asking myself why the investigators at NIST did not respond to that question.

The bottom line is we now know that the girder could have not come off that seat and it is clear from the discovery that there were serious omissions and a seat width distortion, which happened to match the maximum expansion of the beams to get the girder web past the edge of the seat, that there was some level of malfeasance on the part of someone at NIST to make it look like it could have.

With all that has come out, anyone who still says girder A2001 could have walked off its seat at column 79 is only fooling themselves or trying to fool others.
Click to expand...

Yet none of the engineers and professionals working together with this "someone" noticed anything. :rolleyes:
 
Tony Szamboti said:
It is fascinating that you have no issue believing five out of six 7/8" diameter ASTM A325 bolts broke on each of the five beam connections from the east to girder A2001,
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Six bolts? I thought they were fin connections, not header connections. Fin connections had three bolts.

But failure of the welds was considered as a factor too.


Tony Szamboti said:
but can't identify a reaction force that would have caused it besides the one small beam framing into it from the west.
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I identified another one. I gave two possibilities and you're talking about one of them only.


Tony Szamboti said:
Although it is moot because of the above, I thought I would point out that, if all bolts failed and the beams fell onto the top of the bottom flange of the girder then there would be a shortage of expansion as the beams had a 3/4" clearance from the girder web. Now the beams would have to expand 6.25" + .75" = 7.00". You can't get that amount of expansion from 53 foot long steel beams with an 87.5 psf floor load on them at any temperature. It is known that the maximum expansion would have been 5.5".
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And? Leveraging could make the 5.5" be 7.0" at the seat. It just needs a leveraging factor of 1.273, which in a crude estimation it seems to me that could be attained by the expansion of the second beam closest to column 79, if the closest beam's connection and the girder-to-column connection bolts had already failed. You (and gerrycan) are assuming all the beams expanded at the same time by the same length and pushed the girder in a direction parallel to its original position. That's not necessarily right.
 
pgimeno said:
Six bolts? I thought they were fin connections, not header connections. Fin connections had three bolts.

But failure of the welds was considered as a factor too.



I identified another one. I gave two possibilities and you're talking about one of them only.



And? Leveraging could make the 5.5" be 7.0" at the seat. It just needs a leveraging factor of 1.273, which in a crude estimation it seems to me that could be attained by the expansion of the second beam closest to column 79, if the closest beam's connection and the girder-to-column connection bolts had already failed. You (and gerrycan) are assuming all the beams expanded at the same time by the same length and pushed the girder in a direction parallel to its original position. That's not necessarily right.
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You just keep assuming beam connection bolts broke, and now even need to pick and choose which broke, yet you can't even identify a plausible reaction force that would cause them to break. I don't think your theory is on solid ground to begin with and don't see where a reaction force would have come from to break the bolts or welds on the beam to girder connections.

The fin connections on girder A2001 had six 7/8" diameter ASTM A325 bolts each. The welds were every bit as robust as the bolts with 1/4" full length fillets on both sides of the 20" high fin plate to the web and 5/16" fillets on both sides of the 4" wide top to the underside of the top flange of the girder.
 
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Tony Szamboti said:
You just keep assuming beam connection bolts broke, and now even need to pick and choose which broke, yet you can't even identify a plausible reaction force that would cause them to break. I don't think your theory is on solid ground to begin with and don't see where a reaction force would have come from to break the bolts or welds on the beam to girder connections.

The fin connections on girder A2001 had six 7/8" diameter ASTM A325 bolts each. The welds were every bit as robust as the bolts with 1/4" full length fillets on both sides of the 20" high fin plate to the web and 5/16" fillets on both sides of the 4" wide top to the underside of the top flange of the girder.
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Sorry about the number of bolts, I misunderstood. Still, the analysis NIST made accounted for all of these factors, not just the bolts and the welds:

The connection model accounted for: (1) shear failure of individual bolts, (2) tear-out failure at each bolt location, (3) vertical block shear failure of the connection plate, (4) horizontal block shear failure of the web or connection plate, and (5) vertical and horizontal failure of the connection plate-to-column weld.
​
(NCSTAR 1-9 p.476)

If one beam expands while the others don't, what happens first? the girder bending significantly, the beam buckling, or the connection failing?

That's one source of reaction forces: the ones coming from the non-failed connections.
 
pgimeno said:
Sorry about the number of bolts, I misunderstood. Still, the analysis NIST made accounted for all of these factors, not just the bolts and the welds:

The connection model accounted for: (1) shear failure of individual bolts, (2) tear-out failure at each bolt location, (3) vertical block shear failure of the connection plate, (4) horizontal block shear failure of the web or connection plate, and (5) vertical and horizontal failure of the connection plate-to-column weld.
​
(NCSTAR 1-9 p.476)

If one beam expands while the others don't, what happens first? the girder bending significantly, the beam buckling, or the connection failing?

That's one source of reaction forces: the ones coming from the non-failed connections.
Click to expand...

Without shear studs beams K3004, C3004, B3004, and A3004 would buckle well before any bolts break on their connections to girder A2001. So if one of them was expanding while the others weren't it would just buckle with no bolts breaking on any of the other beams.

The reality is that there is no reaction force capable of breaking the bolts or welds of the beam connections on the east side of girder A2001.
 
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Reactor drone said:
The Finite Element Analysis would seem to disagree with your bare assertion.
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And this is this little tidbit from the report as well.

"Connection damage was typically gradual, with bolts and/or welds failing sequentially over time."

(pg 490 NIST NCSTAR 1-9)

And also
The temperature of the girder between Columns 76 and 79 on Floor 13 was sufficient to displace Column 76 to the west and Column 79to the east
(pg 527 NIST NCSTAR 1-9)
 
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Tony Szamboti said:
Without shear studs beams K3004, C3004, B3004, and A3004 would buckle well before any bolts break on their connections to girder A2001. So if one of them was expanding while the others weren't it would just buckle with no bolts breaking on any of the other beams.

The reality is that there is no reaction force capable of breaking the bolts or welds of the beam connections on the east side of girder A2001.
Click to expand...

Reactor drone said:
The Finite Element Analysis would seem to disagree with your bare assertion.
Click to expand...

Time for AE911T to do its own FEA with all the elements on the entire three floors involved, and including a completely faithfull set of enviromental conditions(probably need to run the program a few times, bracketing some variables).
I am sure that a few thousand engineers working on this can come up with the total set of parameters required and, if Gage will simply curtail his vacation speaking tour for a a few months, I am sure the computer time can be had and paid for, even if it requires a fund raising push.
 
Animal said:
And this is this little tidbit from the report as well.

"Connection damage was typically gradual, with bolts and/or welds failing sequentially over time."

(pg 490 NIST NCSTAR 1-9)

And also
The temperature of the girder between Columns 76 and 79 on Floor 13 was sufficient to displace Column 76 to the west and Column 79to the east
(pg 527 NIST NCSTAR 1-9)
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Well, isn't that interesting.......
 
pgimeno said:
ch4-021.jpg


.
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That picture is probably the single best illustration of hot column creep.
 
jaydeehess said:
Well, isn't that interesting.......
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A search of JREF finds BasqueArch making the same point in Jun 2012. TS ignores it and argues about something else BA said ....

May 2012 tfk had made the same point. TS demands figures showing how the girder could manage that without buckling before the column did. (I think he ignored elastic buckling of the column, but no engineer me)

etc etc etc etc etc

very late edit ;) :

TS will hammer the same points until he gets a 'new investigation'
He will never get a new investigation.
He will, therefore, continue to hammer the same points until the cows come home.
The cows will never come home. They're just fine where they are. They need no 'home'.
 
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