RFC: Bazant and Zhou Simple Analysis refuted

[Tony Szamboti]

Fine, Tony, I'll play your little game. Let's assume, just for the sake of argument, that everything you said directly relating to Bazant's calculations is true and that his model should actually show collapse arrest. So what? It's a theoretical calculation that doesn't match the real world. In the real world, the column ends don't line up neatly and land on each other like in some cartoon world. Even if direct column-to-column impacts would have arrested the collapse (and I have seen no evidence to suggest that is the case), that isn't what actually happened on 9/11, so your argument seems to be nothing more than an elaborately constructed strawman.

It could also mean an artificially instigated and propagated collapse took place.

 

[Tony Szamboti]

For Bazant’s North Tower Ideal Model Inelastic Energy Dissipation analysis:

Here’s Bazant’s explanation for the buckling columns question:
Also read preamble to the following:
“The energy dissipation, particularly that due to the inelastic
deformation of columns during the initial drop of the upper
part, may be neglected, i.e., the upper part may be assumed to
move through distance h almost in a free fall (indeed, the energy
dissipated in the columns during the fall is at most equal to 2 pi X
the yield moment of columns, X the number of columns, which is
found to be only about 12% of the gravitational potential energy
release if the columns were cold, and much less than that at
800°C)”
http://www.civil.northwestern.edu/pe...Papers/405.pdf

Your buckling resistance is disputed.
Your velocity estimate by the difference of the buckling columns and 1 floor factor question is disputed.

Also Bazant’s calculations is for the Ideal Model of square and simultaneous column impacts, you’re erroneously mixing it with the north wall fall measurements (to be proven) of the Actual Event. The Actual Event global collapse is well proven, columns didn't hit squarely and simultaneously, they hit the slab or missed, floors hit floors, the CD explanation is not.
The mass calculations are mathematically simple but tedious, and what the most accurate estimate is, is disputed.
This difference in plastic energy dissipation of the columns below is disputed.

Here’s Bazant’s explanation of the two floors factor:
Also read preamble to the following:
“To attain the combined rotation angle (insert formula) of the plastic
hinges on each column line, the upper part of the building must
move down by the additional distance of at least one floor below
the floor where the collapse started”. -ibid
Your one floor factor is disputed.

Your mass, velocity, buckling resistance, one story factor, and plastic energy dissipation by the columns below are disputed and this is the forum to prove it. You haven’t done so.
The question to be resolved in this lightweight subforum is whether one of the two Bazant’s Ideal Model analyses, even if adjusted, show that there was more kinetic energy produced than could be resisted by the columns below. You haven’t falsified it.
No CD, no US government conspiracy collapsed the Towers. The terrorists did it.

You say my values are disputed, but you give no basis for this. Nobody here has been able to dispute these values. There are papers currently in review that show the values used by Dr. Zdenek Bazant and his co-authors in their WTC papers are incorrect and when corrected give a very different result.

 

[ozeco41]

It could also mean an artificially instigated and propagated collapse took place.

Not so Tony. Again you confuse an abstract model with reality.

If you show that Bazant was wrong then it shows that Bazant was wrong with an abstract model. It has zero effect on real world. Its only 'reality' is within the context that Bazant set and the assumptions he adopted. And it was only intended to relate in a limited way to reality.

This is exactly the same error as you seem to be pursuing with 'Prove NIST wrong on "Girder Walkoff" '. If NIST was wrong on that one then NIST was wrong. Wrong on an explanation given years after the event. Right or wrong it cannot change the facts of history. And, for that reason, it gives no support to any desire you have to prove 'artificially instigated and propagated collapse'.

Ditto if Bazant was wrong in Bazant and Zhou - whichever version. If Bazant was wrong it proves that Bazant was wrong with an abstract model. The model therefore loses utility to the extent that its use is limited by the errors. And no further. It also cannot change the facts of history in the real event. For what it is worth I am not a dedicated Bazantophile. I am aware of flaws in his work - starting with B&Z and getting worse IMO in his later papers. For those reasons (and one other) I never rely on Bazant or NIST or any other authority figure - the advantage of being an engineer - I can reason these matters for myself to limits which meet my needs and most of what gets posted here.

Whether or not there was 'an artificially instigated and propagated collapse' is an issue of fact in the real world events of 9/11 2001. Proof of such artificially instigated and propagated event depends on the facts of 9/11 2001 in the real world. Nothing written by Bazant two days (or several months) later nor anything written by NIST several years later can post event in hindsight rewrite the history of what actually happened.

Your several pursuits of dead ends of logic are doomed to fail as measures of proof of 'artificially instigated and propagated collapse'. If you want or need to prove 'CD' you will need to start at the right end of the logic and build a reasoned hypothesis based on evidence. No amount of starting with detailed anomalies will achieve your goal. The most likely outcome in those cases is that you will end up with an anomaly that someone has rebutted for you OR an anomaly that you cannot explain and nobody has explained for you.

 

[LSSBB]

Your several pursuits of dead ends of logic are doomed to fail as measures of proof of 'artificially instigated and propagated collapse'. If you want or need to prove 'CD' you will need to start at the right end of the logic and build a reasoned hypothesis based on evidence. No amount of starting with detailed anomalies will achieve your goal. The most likely outcome in those cases is that you will end up with an anomaly that someone has rebutted for you OR an anomaly that you cannot explain and nobody has explained for you.

^This.

 

[NutCracker]

It could also mean an artificially instigated and propagated collapse took place.

Nope. It's good old 'lump everything in the 'official story' together, find anomaly, consider 'official story' falsified, therefore, by False Dillema, it follows that my pet theory, for which I cannot even dream of beginning to build a case, is true'.

 

[twinstead]

I love God of the Gaps.

 

[Tony Szamboti]

Not so Tony. Again you confuse an abstract model with reality.

If you show that Bazant was wrong then it shows that Bazant was wrong with an abstract model. It has zero effect on real world. Its only 'reality' is within the context that Bazant set and the assumptions he adopted. And it was only intended to relate in a limited way to reality.

This is exactly the same error as you seem to be pursuing with 'Prove NIST wrong on "Girder Walkoff" '. If NIST was wrong on that one then NIST was wrong. Wrong on an explanation given years after the event. Right or wrong it cannot change the facts of history. And, for that reason, it gives no support to any desire you have to prove 'artificially instigated and propagated collapse'.

Ditto if Bazant was wrong in Bazant and Zhou - whichever version. If Bazant was wrong it proves that Bazant was wrong with an abstract model. The model therefore loses utility to the extent that its use is limited by the errors. And no further. It also cannot change the facts of history in the real event. For what it is worth I am not a dedicated Bazantophile. I am aware of flaws in his work - starting with B&Z and getting worse IMO in his later papers. For those reasons (and one other) I never rely on Bazant or NIST or any other authority figure - the advantage of being an engineer - I can reason these matters for myself to limits which meet my needs and most of what gets posted here.

Whether or not there was 'an artificially instigated and propagated collapse' is an issue of fact in the real world events of 9/11 2001. Proof of such artificially instigated and propagated event depends on the facts of 9/11 2001 in the real world. Nothing written by Bazant two days (or several months) later nor anything written by NIST several years later can post event in hindsight rewrite the history of what actually happened.

Your several pursuits of dead ends of logic are doomed to fail as measures of proof of 'artificially instigated and propagated collapse'. If you want or need to prove 'CD' you will need to start at the right end of the logic and build a reasoned hypothesis based on evidence. No amount of starting with detailed anomalies will achieve your goal. The most likely outcome in those cases is that you will end up with an anomaly that someone has rebutted for you OR an anomaly that you cannot explain and nobody has explained for you.

If the NIST/Bazant explanation is in error then a new investigation is warranted.

 

[twinstead]

If the NIST/Bazant explanation is in error then a new investigation is warranted.

Says who? My tax money isn't going to be spent because a few people on an obscure internet forum think there needs to be a new investigation. You folks need to get cracking on convincing people who have some weight that you're right because no offence, but I could give a crap about what you think.

 

[thedopefishlives]

If the NIST/Bazant explanation is in error then a new investigation is warranted.

You are conflating two different things. This thread is about Bazant, so I am ignoring your reference to NIST for the present. If Bazant is wrong, Bazant is wrong, full stop. It is a theoretical model meant to imply that the building would have collapsed no matter what. Even if he is wrong on that count, Bazant does not factor into the so-called "official theory" because it is not intended to reflect reality. You're tilting at windmills here, Tony; disproving Bazant adds nothing to your case concerning what really happened on 9/11. All it does is invalidate a theoretical mathematical construct.

 

[BasqueArch]

You say my values are disputed, but you give no basis for this. Nobody here has been able to dispute these values. There are papers currently in review that show the values used by Dr. Zdenek Bazant and his co-authors in their WTC papers are incorrect and when corrected give a very different result.

You're obliviously wrong to what I posted.

 

[Tony Szamboti]

You're obliviously wrong to what I posted.

Hardly. Bazant's own paper shows he is completely wrong to assume freefall during buckling. Take a look at figures 5d and e in the Bazant and Zhou paper and use them to figure out what the minimum resistance of the columns would be during buckling and get back to me.

 

[Seymour Butz]

Hardly. Bazant's own paper shows he is completely wrong to assume freefall during buckling. Take a look at figures 5d and e in the Bazant and Zhou paper and use them to figure out what the minimum resistance of the columns would be during buckling and get back to me.

In the real world?

Zero resistance, since as he points out, they would fracture after only a few degrees of rotation.

But in his model?

The maxwell line lies at about what? 1/3 of design load?

 

[Tony Szamboti]

In the real world?

Zero resistance, since as he points out, they would fracture after only a few degrees of rotation.

But in his model?

The maxwell line lies at about what? 1/3 of design load?

By design structural steel is extremely ductile and has an elongation of about 20% before fracture. To give you an idea, a 12 foot long buckling column would have to stretch over 2 feet before fracture. So there is no way they would fracture after a few degrees of rotation. That is smoke blowing nonsense. Where are Bazant's tests or citations showing what he claimed there?

 

[Seymour Butz]

By design structural steel is extremely ductile and has an elongation of about 20% before fracture. To give you an idea, a 12 foot long buckling column would have to stretch over 2 feet before fracture. So there is no way they would fracture after a few degrees of rotation. That is smoke blowing nonsense. Where are Bazant's tests or citations showing what he claimed there?

Well, of course I'm being nice and not mentioning the column splices either....

 

[Seymour Butz]

Oh.

And of course I'm also being nice and not pointing out that in reality, the east and west ext columns can beseen shearing off and not forming plastic hinges. So now we can eliminate the south, east, and west walls from supplying any buckling resistance.

Right?

 

[Tony Szamboti]

Well, of course I'm being nice and not mentioning the column splices either....

Column splices are generally designed to maintain the strength of the column and they wouldn't just fracture and let go after a few degrees of rotation either.

Again where are the tests or citations to back up this claim for fracture after a few degrees of column rotation permitting freefall acceleration through the first story of the fall in WTC 1?

 

[Tony Szamboti]

Oh.

And of course I'm also being nice and not pointing out that in reality, the east and west ext columns can beseen shearing off and not forming plastic hinges. So now we can eliminate the south, east, and west walls from supplying any buckling resistance.

Right?

I am speaking of WTC 1 and there it would have been impossible for the exterior walls to shear off during the first story of the fall.

I would like to hear your explanation for how that could happen if you really believe that.

 

[Seymour Butz]

Column splices are generally designed to maintain the strength of the column and they wouldn't just fracture and let go after a few degrees of rotation either.

Photographs have been examined at a certain truther site ( you know where ) and it has been determined that is exactly what happened.

Or do you dispute ie?

Again where are the tests or citations to back up this claim for fracture after a few degrees of column rotation permitting freefall acceleration through the first story of the fall in WTC 1?

I'd say that the proof lies:

in the hundreds of his peers that read it, and none challenged him on this.

 

[Animal]

Column splices are generally designed to maintain the strength of the column and they wouldn't just fracture and let go after a few degrees of rotation either.

Again where are the tests or citations to back up this claim for fracture after a few degrees of column rotation permitting freefall acceleration through the first story of the fall in WTC 1?

Please list any structures you have been involved with so that we can stay far away from them.

If you really believe the connections were designed for the same tensile loading that the steel section could have maintained, you are then a seriously incompetent engineer

 

[Tony Szamboti]

Please list any structures you have been involved with so that we can stay far away from them.

If you really believe the connections were designed for the same tensile loading that the steel section could have maintained, you are then a seriously incompetent engineer

Seismic loading requires the splicing to be as strong (or nearly as strong) in bending, which is what buckling entails. That is not a pure tensile requirement.