Total Building Collapse from a Single Column Failure

[LSSBB]

When the center of gravity of an object is beyond the edges of its support, the object will roll off of its support. You can experiment with this with a cardboard box and a table (don't tell Richard Gage, this is a really focused experiment and he might get the wrong idea). No local deformation of the flange is required.

This was about what I was thinking, anyway. Still it's not important what I think about the exact mechanism. I am not trying to tear down NIST. Those that aim to do so on this forum have yet to present anything near a complete case against NIST's specific likely failure cause for column 79, let alone against the overall conclusion. It's like they have no patience to get to a final answer.

 

[Tony Szamboti]

When the center of gravity of an object is beyond the edges of its support, the object will roll off of its support. You can experiment with this with a cardboard box and a table (don't tell Richard Gage, this is a really focused experiment and he might get the wrong idea). No local deformation of the flange is required.

It is hard to imagine how you think this can happen with the five beams to the east still fastened to the girder with six bolts each. The Cg of the assembly is in the middle of the floor not on the girder's longitudinal axis.

Do you believe those connections had failed in some way simultaneous with the web moving past the seat?

Additionally, the girder could only be pushed 5.5 inches by the beams and with a 12 inch seat that does not put the web past the seat.

 

[Newtons Bit]

It is hard to imagine how you think this can happen with the five beams to the east still fastened to the girder with six bolts each. The Cg of the assembly is in the middle of the floor not on the girder's longitudinal axis.

Do you believe those connections had failed in some way simultaneous with the web moving past the seat?

The beams were not connected to the girder with moment connections. They provide no vertical support to the girder (prior to catenary action anyways, which requires a deflection of the girder that can only happen when the girder is off its end supports).

Additionally, the girder could only be pushed 5.5 inches by the beams and with a 12 inch seat that does not put the web past the seat.

Evidence?

 

[LSSBB]

It is hard to imagine how you think this can happen with the five beams to the east still fastened to the girder with six bolts each. The Cg of the assembly is in the middle of the floor not on the girder's longitudinal axis.

Do you believe those connections had failed in some way simultaneous with the web moving past the seat?

Additionally, the girder could only be pushed 5.5 inches by the beams and with a 12 inch seat that does not put the web past the seat.

Where is the force being applied, at the assembly Cog or the connection? Also, there are 3 dimensions at play, not 2.

 

[Justin39640]

Where is the force being applied, at the assembly Cog or the connection? Also, there are 3 dimensions at play, not 2.

(cough) column on column impacts (cough)

 

[Tony Szamboti]

The beams were not connected to the girder with moment connections. They provide no vertical support to the girder (prior to catenary action anyways, which requires a deflection of the girder that can only happen when the girder is off its end supports).

There were six bolts on each fin connection of the beams to the girder. The fin connections were welded to the underside of the girder flange and to its web. The six bolts on each connection were 7/8" dia. ASTM A325 which would not shear at less than 35,000 lbs. The fin welds and bolts would easily resist the small moment applied by the girder's center moving past the edge of the seat.

Evidence?

The calculation for thermal expansion of a 53 foot long steel beam shows the maximum expansion is about 5.5 inches at just above 600 degrees C, as after that with a floor load of 87.5 psf the W24 x 55 beams will shorten from sagging more than they expand.

 

[Newtons Bit]

The calculation for thermal expansion of a 53 foot long steel beam shows the maximum expansion is about 5.5 inches at just above 600 degrees C, as after that with a floor load of 87.5 psf the W24 x 55 beams will shorten from sagging more than they expand.

And the beams were of unequal length and unevenly heated, which will cause the girder to rotate. The column itself will also deflect laterally.

We've been over this before. It was then, and it's now.

 

[Tony Szamboti]

And the beams were of unequal length and unevenly heated, which will cause the girder to rotate. The column itself will also deflect laterally.

We've been over this before. It was then, and it's now.

The beam closest to the seat at column 79 (K3004) would restrain the girder if any other beam tried to rotate it.

Are you trying to say the girder framing in from the west pushed the column to the east? If so, how would it have done so with all of the beams framing into it from both the north and south which all had large numbers of shear studs on them?

I don't recall hearing the "rolled off" theory that you are now espousing and there are problems with it in that it can't happen since the connections of the beams from the east would easily resist any small moment which would occur with the girder's web past the seat. The stiffeners would then keep the flange from failing. The girder would always be supported by the seat and cannot fall.

 

[JayUtah]

I don't recall hearing the "rolled off" theory that you are now espousing.

I don't recall seeing where NIST specifically argued that the girder seat connection failed by plastic deformation of the flange, such as would have been prevented in the model by the "omitted" transverse stiffener. "Walk-off" is the language the report uses, which implies (but does not specify) any of a number of particular behaviors. That reduces your claim to an elaborately expressed straw man.

 

[LSSBB]

I don't recall seeing where NIST specifically argued that the girder seat connection failed by plastic deformation of the flange, such as would have been prevented in the model by the "omitted" transverse stiffener. "Walk-off" is the language the report uses, which implies (but does not specify) any of a number of particular behaviors. That reduces your claim to an elaborately expressed straw man.

Boy, does that sound familiar, like with the paper Tony submitted. It's like all this was written by Cervantes.

 

[Tony Szamboti]

I don't recall seeing where NIST specifically argued that the girder seat connection failed by plastic deformation of the flange, such as would have been prevented in the model by the "omitted" transverse stiffener. "Walk-off" is the language the report uses, which implies (but does not specify) any of a number of particular behaviors. That reduces your claim to an elaborately expressed straw man.

It is hardly a strawman as contrary to what you are saying the report does indeed specify what would have failed in the NIST scenario and why.

Paragraph 11.2.9 of NIST NCSTAR 1-9 states that

when the web was no longer supported by the bearing seat, the beam was assumed to have lost support, as the flexural stiffness of the bottom flange was assumed to be insufficient for transferring gravity loads.

The flexural stiffness to transfer the gravity loads after the web was past the seat is exactly what the omitted 3/4" thick x 5.5" wide x 18" high stiffeners, welded with two full length 3/8" fillets to the flange and two full length 5/16" fillets to the web, would have provided and the girder would not fall. They need to be put back and the analysis rerun.

 

[JayUtah]

It is hardly a strawman as contrary to what you are saying the report does indeed specify what would have failed in the NIST scenario and why.

Still misleading. However thank you for providing the reference. I did look for it in good faith, but relied upon your burden of proof to produce it more quickly and reliably.

Paragraph 11.2.9 of NIST NCSTAR 1-9 states...

Section 11.2.9 discusses the criteria for identifying a member as "failed" in the ANSYS model. The passage in question applies to all types of seated girder connections, whether stiffened in the construction or not. I concede there is discussion of failure by means of plastic deformation of the flange, implied by the language "loss of flexural stiffness." I withdraw the accusation of straw-man tactics; the case was indeed discussed. However the context makes clear it is a general criteria applied to a class of similar but not identical connections. It does not mention, but similarly does not preclude other modes of failure, nor imply that all such seated connections would have necessarily behaved identically.

Elsewhere NIST discusses specifically the critical failure at column 79 in greater detail and does not there identify flange deformation as the necessary failure mode. I do not believe it is appropriate to restrict their discussion there -- pages and pages away and in specific contexts -- to the general criteria identified in the overarching algorithm.

I wrote above that structural analysis is not simply plugging data into a computer and reading the asserted answer at the bottom of the printout, metaphorically speaking. NIST used the global structural model (with all its various approximations and generalizations) to inform an intellectual argument that focused in greater depth on where and how the model suggested the initiation of the structure's failure occurred.

 

[beachnut]

It is hardly a strawman as contrary to what you are saying the report does indeed specify what would have failed in the NIST scenario and why.

Paragraph 11.2.9 of NIST NCSTAR 1-9 states that

when the web was no longer supported by the bearing seat, the beam was assumed to have lost support, as the flexural stiffness of the bottom flange was assumed to be insufficient for transferring gravity loads.

The flexural stiffness to transfer the gravity loads after the web was past the seat is exactly what the omitted 3/4" thick x 5.5" wide x 18" high stiffeners, welded with two full length 3/8" fillets to the flange and two full length 5/16" fillets to the web, would have provided and the girder would not fall. They need to be put back and the analysis rerun.

And now how you back in CD, thermite and the silent explosives? Who put them in WTC7? What is your probable cause which beats NIST's probable cause. Probable means?

Why does this always boil down to the silly need a new investigation when 911 truth has all those expert who could do the new investigation themselves, team with a newspaper, earn a Pulitzer, and win. After 12 years of nonsense, and no evidence.

Better yet NWO posters, JREF shills, take the weekend off, we are short on overtime - see you Monday. Funds are short, we have to cut back on fighting woo - take the grandkids to the park. Where is 911 truth hiding the evidence which would be used to justify a new investigation? Where is the engineering excellence 911 truth CD believers claim to have?

When will you team with a newspaper for the big Pulitzer? If the single column failure failed to cause the collapse, what is the 911 truth CD probable cause?
Wait, time out, we are all unfunded for the weekend, Tony, come back Tuesday, we have to cut our hours. You knew it, yes, we are the NWO fighting woo - funded by a "secret" cabal. (extra secret added for effect). When are you and Balsamo going to be on TV again?

 

[Animal]

Yeah, he means the column flange.

Yes I knew that. I could not resist slapping him upside the head with his own ignorance.

One of the easy ways to tell whether someone is a genuine expert or bluffing is whether he is familiar with the specialized vocabulary of the relevant field.

It i also easy based on the nonsense they spew.

Also, I wonder how long it will take him to realize that his "sideplate" argument also dooms his flange-deformation hypothesis, since his diagram with the sad-flanged green girder also must displace and rotate in a way that "sideplates" would not allow, if they were a factor. (Hint: column 79 were essentially box columns, having no significant "sideplate" [flange].)

At Column 79 the girder was connected to the face of the flange....at the exterior columns, the girder was connected to the web.

This is what happens when one's objections are knee-jerk ideological responses rather than carefully considered engineering rationales.

Can I get an AMEN with that?

 

[BasqueArch]

<snip>

Better yet NWO posters, JREF shills, take the weekend off, we are short on overtime - see you Monday. Funds are short, we have to cut back on fighting woo - take the grandkids to the park. Where is 911 truth hiding the evidence which would be used to justify a new investigation? Where is the engineering excellence 911 truth CD believers claim to have?
......................
Wait, time out, we are all unfunded for the weekend, Tony, come back Tuesday, we have to cut our hours. You knew it, yes, we are the NWO fighting woo - funded by a "secret" cabal. (extra secret added for effect). When are you and Balsamo going to be on TV again?

I’m on the Giuliani weekend shift. Can you finish the supersurround 16.1 speakers and 3D LED box you promised me last year. Thanks.

http://www.youtube.com/watch?v=dVHP7Nhsn4E

 

[BasqueArch]

And the beams were of unequal length and unevenly heated, which will cause the girder to rotate. The column itself will also deflect laterally.

We've been over this before. It was then, and it's now.

Yes, we did this a year or two ago; tramnesia.

 

[BasqueArch]

Regarding Pepper’s and TS’s claim that WTC7 could not have failed in a fire:

There are many ways that the WTC7 13th floor girder or floor beams could have failed in a fire. The only question is which one most probably happened first.

1) The expanding beams pushed the girder laterally off the seat. The assumed 600C beams and 500C girder temperatures were the NIST one floor boundary conditions. The 16 floor model was based on the calculated fire dynamics model gas temperatures greater than 600C which were then fed to the structural global FEA. The 16 floor model analysis shows that the beams had lost most of their girder attaching bolts. NCSTAR 1-9 pdf p.577. Once the web was past the seat the girder rotated and sheared the remaining few beam bolts. The partial web stiffeners made no difference to the failure of the beams to keep the girder atop the seat.

“ Note that, in the detailed finite element analyses of the 16-story ANSYS model (see Chapter 11), no boundary conditions were applied to the floor slabs, and the temperatures of both the steel and concrete were derived from a thermal analysis based on fire dynamics calculations.”[FONT=&quot] www.nist.gov/customcf/get_pdf.cfm?pub_id=861611[/FONT]
[FONT=&quot]Pdf p.393[/FONT]

2) The girder expanded and trapped by the columns at both ends buckled , the girder changing from top flange compression to a sagging catenary with a severe sag much greater than the 2-3” deflection TS claims. The girder falls off the seat axially, in the direction away from the column.

3) The girder sags, the weight of the girder is now tangentially on the tip of the unsupported hot seat and to one side, the seat bends or shears, the girder falls.

4) The sagging buckled weakened girder forms a plastic hinge and collapses in bending.

5) Lateral torsional buckling of the girder. NIST shows this as the failure mode of girder 79-44. The beams were eccentrically attached near the top and asymmetrically on one side only of the girder. The girder construction bolts had sheared and the ends were unrestrained, free to rotate. The moment beams rotated the girder. Once the girder web and flanges had lost their vertical load carrying geometry through rotation then the girder failed.

“After failure of the erection bolts in the seat at Column 44, continued axial expansion of the floor beams pushed the girder laterally, where it came to bear against the inside of the column flange. Axial compression then increased in the floor beams, and at a beam temperature of 436°C, the northmost beam began to buckle laterally. Buckling of other floor beams followed as shown in Figure 8–27 (a), leading to collapse of the floor system, and rocking of the girder off its seat at Column 79 as shown in Figure 8–27 (b).”
[FONT=&quot] NCSTAR 1-9 pdf p.397 and figure on pdf p.398.[/FONT]

6) The girder rotated shearing the few remaining beams bolts, the floor collapsed.
------------------------------------------------
Regarding the claim that NIST is part of The Conspiracy by leaving out some details.

1) NIST added a seat stiffener at the 13th floor column 79 to prevent the seat from failing.In the plans there is not a stiffener plate under the seat at cols. 79 or 81. NIST modeled these connections as stiffened seats and added these stiffener plates as shown on Figures 12-25 and 12-26:
“Since vertical failure of the seat was not considered (Section 11.2.5), the connections at Columns 79 and 81 were both modeled as stiffened seats.”
(NCSTAR 1-9 pdf 624,625)
http://www.nist.gov/customcf/get_pdf.cfm?pub_id=861611

2) NIST fixed the columns from moving in the partial floor model.

3) NIST in their global model added the braces at the last perimeter beam.

4) NIST could have removed the partial web stiffeners and bracing from the drawings they provided.

5) Girder connections to column 79 on some other floors did not have web stiffeners.

6) NIST animated approximated collapse model could have been doctored to exactly match the video.

---------------------------------------------------------------

Fire caused the collapse of WTC7 not CD.

Will reason and evidence change a 911 True Believer’s conspiracy conviction that CD caused the collapse of WTC7? No, it won’t because they can’t help it.

The conspiratorial amygdala-prefrontal cortex condition is involuntary and automatic. Like synesthesia/ideasthesiasts they’re wired that way.

http://www.sharecare.com/health/functions-of-the-brain/brains-emotions

 

[Tony Szamboti]

Regarding Pepper’s and TS’s claim that WTC7 could not have failed in a fire:

There are many ways that the WTC7 13th floor girder or floor beams could have failed in a fire. The only question is which one most probably happened first.

1) The expanding beams pushed the girder laterally off the seat. The assumed 600C beams and 500C girder temperatures were the NIST one floor boundary conditions. The 16 floor model was based on the calculated fire dynamics model gas temperatures greater than 600C which were then fed to the structural global FEA. The 16 floor model analysis shows that the beams had lost most of their girder attaching bolts. NCSTAR 1-9 pdf p.577. Once the web was past the seat the girder rotated and sheared the remaining few beam bolts. The partial web stiffeners made no difference to the failure of the beams to keep the girder atop the seat.

“ Note that, in the detailed finite element analyses of the 16-story ANSYS model (see Chapter 11), no boundary conditions were applied to the floor slabs, and the temperatures of both the steel and concrete were derived from a thermal analysis based on fire dynamics calculations.”[FONT=&quot] www.nist.gov/customcf/get_pdf.cfm?pub_id=861611[/FONT]
[FONT=&quot]Pdf p.393[/FONT]

2) The girder expanded and trapped by the columns at both ends buckled , the girder changing from top flange compression to a sagging catenary with a severe sag much greater than the 2-3” deflection TS claims. The girder falls off the seat axially, in the direction away from the column.

3) The girder sags, the weight of the girder is now tangentially on the tip of the unsupported seat and to one side, the seat bends or shears, the girder falls.

4) The sagging buckled weakened girder forms a plastic hinge and collapses in bending.

5) Lateral torsional buckling of the girder. NIST shows this as the failure mode of girder 79-44. The beams were eccentrically attached near the top and asymmetrically on one side only of the girder. The girder construction bolts had sheared and the ends were unrestrained, free to rotate. The moment beams rotated the girder. Once the girder web and flanges had lost their vertical load carrying geometry through rotation then the girder failed.

“After failure of the erection bolts in the seat at Column 44, continued axial expansion of the floor beams pushed the girder laterally, where it came to bear against the inside of the column flange. Axial compression then increased in the floor beams, and at a beam temperature of 436°C, the northmost beam began to buckle laterally. Buckling of other floor beams followed as shown in Figure 8–27 (a), leading to collapse of the floor system, and rocking of the girder off its seat at Column 79 as shown in Figure 8–27 (b).”
[FONT=&quot] NCSTAR 1-9 pdf p.397 and figure on pdf p.398.[/FONT]

6) The girder rotated shearing the few remaining beams bolts, the floor collapsed.
------------------------------------------------
Regarding the claim that NIST is part of The Conspiracy by leaving out some details.

1) NIST added a seat stiffener at the 13th floor column 79 to prevent the seat from failing.In the plans there is not a stiffener plate under the seat at cols. 79 or 81. NIST modeled these connections as stiffened seats and added these stiffener plates as shown on Figures 12-25 and 12-26:
“Since vertical failure of the seat was not considered (Section 11.2.5), the connections at Columns 79 and 81 were both modeled as stiffened seats.”
(NCSTAR 1-9 pdf 624,625)
http://www.nist.gov/customcf/get_pdf.cfm?pub_id=861611

2) NIST fixed the columns from moving in the partial floor model.

3) NIST in their global model added the braces at the last perimeter beam.

4) NIST could have removed the partial web stiffeners and bracing from the drawings they provided.

5) Girder connections to column 79 on some other floors did not have web stiffeners.

6) NIST animated approximated collapse model could have been doctored to exactly match the video.

---------------------------------------------------------------

Fire caused the collapse of WTC7 not CD.

Will reason and evidence change a 911 True Believer’s conspiracy conviction that CD caused the collapse of WTC7? No, it won’t because they can’t help it.

The conspiratorial amygdala-prefrontal cortex condition is involuntary and automatic. Like synesthesia/ideasthesiasts they’re wired that way.

http://www.sharecare.com/health/functions-of-the-brain/brains-emotions

The NIST structural feature omissions are serious and show that the report's claims do not withstand scrutiny. The analyses need to be rerun with the omitted features included and the results made public.

If you think you know how fire could have caused the collapse initiation of WTC 7 you should inform NIST of your theory.

 

[BasqueArch]

The NIST structural feature omissions are serious and show that the report's claims do not withstand scrutiny. The analyses need to be rerun with the omitted features included and the results made public.

If you think you know how fire could have caused the collapse initiation of WTC 7 you should inform NIST of your theories. It has been shown in the past how some of your theories, such as an axial walk-off of the girder, were not possible.

You have wrongly claimed repeatedly that fire could not have collapsed WTC7, that it was CD.
The lateral torsional failure mode of the girder is NIST's, not mine, you should read their passage I noted above.
The axial walk-off has not "been shown" to be impossible.

 

[Tony Szamboti]

You have wrongly claimed repeatedly that fire could not have collapsed WTC7, that it was CD.
The lateral torsional failure mode of the girder is NIST's, not mine, you should read their passage I noted above.
The axial walk-off has not "been shown" to be impossible.

The northmost beam would not have buckled if the three lateral support beams framing into it the exterior were not omitted from the NIST analysis. So again, the NIST hypothesis is shown to be impossible when the omitted structural features are included in the analysis.