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Total Building Collapse from a Single Column Failure

Collapse occurred as a result of progression from the failure of col 79, and that having occurred low down in the structure. Evidence exists to back this. Furthermore the only phenomena in evidence that could drive this column failure is fire in the vicinity of column 79.

On the other hand neither you or your organization has supplied any evidence to support another driving effect for the failure of column 79, nor any evidence to support the contention that global collapse could not progress from the loss of column 79.

In fact all you have done is complain about NIST without offering a counter analysis that outlines an alternative.

The NIST analysis omitted pertinent structural features which would have seriously changed the outcome. That is not allowed in structural analysis for obvious reasons.
 
Man, if only there was a truthy organization that had raised hundreds of thousands of dollars over the past several years then Tony Szamboti could get the funding he needs to run a full-scale analysis of WTC7...

Or hire a carpenter to do it. Though perhaps some of the actual fellow engineers may wish to take a lead on actual technical work this time. Wonder if say half a dozen out of a few thousand possible candidates could be found.
 
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The NIST analysis omitted pertinent structural features which would have seriously changed the outcome. That is not allowed in structural analysis for obvious reasons.

,,,,, and with that stance having been reiterated many a time, we can thus assume,,,,,

So we can assume that your proposed new FEA containing the effects of the 'left out' structural elements will also include every other nearby element and the effect on each by the , changing, fire environment. It will be a fully faithful model of the two or three floors involved, correct?

One wonders on the supercomputer time required for this run and if more than one run would be done in order to bracket certain variables such as fire gas temps, air supply, and fire duration in specific areas.

Yes? No?
 
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Hmmm, I wonder if the loss of the SW corner of the structure resulted in ANY force at all towards that location, that may have been capable of adding even, say, half an inch extra travel of the girder...... Better include that in the FEA too. Model the full extent of three floors just to be on the safe side.
 
Oh, I am reminded of the report that an elevator car was found having been ejected from its shaft, iirc, at the fifth floor. Now, how to include the damage that caused that to occur in the FEA......
 
The bolt pattern is moment resisting about the longitudinal axis of the girder and so are the welds on top and at the side of the fin plate.

Please show otherwise with some calculations if you think that is not true.

Wow, I'm not sure who to believe, your lies or the actual tests conducted by AISC. What a conundrum. :rolleyes:
 
Or hire a carpenter to do it. Though perhaps some of the actual fellow engineers may wish to take a lead on actual technical work this time. Wonder if say half a dozen out of a few thousand possible candidates could be found.
Wait....................should I be offended here??????????


:(

Does he specialize in cardboard models like Gage?


Watch it, engineer. :p




:boxedin:
 
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Wait....................should I be offended here??????????


:(

Not at all DGM. I was assuming the members of the team would be drawn from the membership of AE911T. However, if there were others, perhaps even yourself, who would be willing to offer their time and expertise, then the pool of talent is just all the greater.
 
Not at all DGM. I was assuming the members of the team would be drawn from the membership of AE911T. However, if there were others, perhaps even yourself, who would be willing to offer their time and expertise, then the pool of talent is just all the greater.
Nice save...................




:D
 
The NIST analysis omitted pertinent structural features which would have seriously changed the outcome. That is not allowed in structural analysis for obvious reasons.

Same mantra repeated over and over again. It's not convincing, for the reasons already given at length. You can chide us here all you want for not taking your word for it, but the ancillary fact remains that practically none of your professional colleagues takes your word for it either.

The process you're following is so far outside professional engineering practice that I'm ashamed. Why is this important? First, because you can't make your arguments under color of professional expertise and authority without properly flying those colors. If you don't present your case with professionalism, you don't get professional respect. Second, in evaluating your argument, we have to determine how genuinely it is directed toward the implied goal; we use that presumption to fill in the gaps in good faith.
 
Wow, I'm not sure who to believe, your lies or the actual tests conducted by AISC. What a conundrum. :rolleyes:

There is no basis for your claim. The five beam fin connections to the girder would have resisted the small moments about the longitudinal axis of the girder, created by the web being past the seat, making your roll off theory a complete non starter and silly on its face.
 
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There is no basis for your claim. The five beam fin connections to the girder would have resisted the small moments about the longitudinal axis of the girder, created by the web being past the seat, making your roll off theory a complete non starter and silly on its face.
Do you mean these fin connections?

Floors 12, 13, and 14. On Floors 12 and 14, most of the floor beams on the south and east floor areas near Columns 78, 81, and 80 had failed. The floor beams either buckled or lost vertical support when all the fin connection bolts had sheared off due to thermal expansion. Both floors had a damage level of 0.75-0.99 in floor beam fin connections extending past Column 79 in the east floor beams (Figure 11-42 and Figure 11-44). The girder between Columns 26 and 81 buckled on Floors 12 and 14 and the girder between Columns 80 and 81 buckled on Floor 14. All four of the erection bolts in the seated connection at Column 79 on Floor 14 had failed.

(NCSTAR 1-9 p.514)

(ETA: See fig. 11-43 for Case C, or fig. 11-35 for Case B)
 
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Do you mean these fin connections?

Floors 12, 13, and 14. On Floors 12 and 14, most of the floor beams on the south and east floor areas near Columns 78, 81, and 80 had failed. The floor beams either buckled or lost vertical support when all the fin connection bolts had sheared off due to thermal expansion. Both floors had a damage level of 0.75-0.99 in floor beam fin connections extending past Column 79 in the east floor beams (Figure 11-42 and Figure 11-44). The girder between Columns 26 and 81 buckled on Floors 12 and 14 and the girder between Columns 80 and 81 buckled on Floor 14. All four of the erection bolts in the seated connection at Column 79 on Floor 14 had failed.

(NCSTAR 1-9 p.514)

(ETA: See fig. 11-43 for Case C, or fig. 11-35 for Case B)

What forces on the fin connections from beams K3004, C3004, B3004, A3004, and G3005 to girder A2001 would cause them to fail?

Don't forget that NIST claims there were no shear studs on girder A2001 so it is hard to see how the bolts would shear since the girder would move before the six 7/8" diameter ASTM A325 bolts sheared. There were 5/16" fillet x 3.75" long welds on both sides of the top of the 3/8" thick fin plates to the girder and 1/4" fillet x 19.5" long welds on both of the sides of the fin plate to the girder. The likelihood of these connections breaking is extraordinarily low, but maybe you can tell us how it could happen.

Are you just taking the NIST WTC 7 report's word for it here? I would think one would know better since the discovery of the pertinent structural feature omissions. So what does your analysis say?
 
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What forces on the fin connections from beams K3004, C3004, B3004, A3004, and G3005 to girder A2001 would cause them to fail?

Don't forget that NIST claims there were no shear studs on girder A2001 so it is hard to see how the bolts would shear since the girder would move before the six 7/8" diameter ASTM A325 bolts sheared. There were 5/16" fillet x 3.75" long welds on both sides of the top of the 3/8" thick fin plates to the girder and 1/4" fillet x 19.5" long welds on both of the sides of the fin plate to the girder. The likelihood of these connections breaking is extraordinarily low, but maybe you can tell us how it could happen.

Are you just taking the NIST WTC 7 report's word for it here? I would think one would know better since the discovery of the pertinent structural feature omissions. So what does your analysis say?

Or more to the point, what does yours say ?
 
Or more to the point, what does yours say ?

It says they are not breaking, as there is only a relatively small force applied to K3004, C3004, B3004, and A3004 which is the force of friction between the girder and the floor pans. In the case of G3005 it would be the friction plus the force to deflect the girder which is still relatively low and would not shear the bolts.

The force to shear each bolt would have been about 35,000 lbs. and there were six at each connection. With the steel beams alleged to have been at 600 degrees C (which puts the steel at 50% of room temperature strength) that would require about 100,000 lbs to shear the bolts at each connection. The friction from the floor on the girder's top flange would have only been a small fraction of that.
 
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Why did you not include this in your letter ?

The NIST analysis of beam G3005, without the three lateral support beams included, does not have its connection to the girder breaking. In that scenario they can't be broken because they need the connections to make their allegation that the girder was rocked off its seats by the beams.

I also think the Pepper letter implies that the connections of the beams to the girder do not break when it says that beam G3005 does not buckle or fail and simply deflects girder A2001 with the three lateral support beams included in the analysis.
 
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