NIST Releases FINAL WTC 7 Report - Nov. 20

[Grizzly Bear]

If you read my article ...<snip>... if you remove column 79 between floors 11/13. Falling debris and other local failures of floor beams/girders connected to column 79 above floors 11/13 are irrelevant. So I remove column 79 between floors 11/13 and there is no collapse!

Question number one; does your model account for the effects of weakened structural members from the effects of elevated temperatures? Does your model account for the effects of thermal expansion and the lateral loads which it induced on connecting components?

I see no mention of either on your write up

Just 6800 tons of weight carried by column 79 is redistributed to adjacent columns via floor beams/girders, as expected; the column stresses increase from <30% yield to <37.5% yield.

Except there's a problem which inherently affects the calculations you [supposedly] applied to the loading conditions. The model you use to base your calculations is incredibly simplified;

First off, the building was constructed on top of a substation which required the construction of three transfer trusses for the first 5 floors, these trusses carried the weight of the structure above it. Your model does not accurately represent this.

Second, your sectional drawings do not accurately represent the varied beam spans which were part of the WTC 7 structural design. Your model assumes that all floor spans are the same; THEY ARE NOT (CLICK)... large floor sections were contingent of individual columns maintaining their integrity.

Third your models do not consider either the effects of fire-induced damage or the long floor spans which would have magnified the effects of thermal expansion and therefore influenced the lateral loads applied to connections not designed for such loads.

As every inner column is supported by four floor girders/beams at every floor level they can never lose any lateral support if column 79 fails locally. The connections are much too strong for that. They do not slip away from the adjacent columns. And if they do, no load is transmitted! The load of column 79 just drops to the ground and the rest of the structure remains standing.

Your model assumes that the structural design of WTC 7 is the traditional post & beam construction, with a skeletal frame found in more traditional steel construction. This is not how WTC 7 was built; and you wonder why your aren't taken seriously?

Yes, I think NIST is doing a lousy work. NIST doesn't know much about structural damage analysis!

That's quite an interesting statement coming from an engineer who has demonstrated that his modeling of both the towers and WTC 7 is not only oversimplified, but wrong. Surely I hope you think about your own faults before lashing out accusations of lousy work, however if you have no problem with being a hypocrite then by all means, please continue.

The NIST analysis with parts flying around is just Hollywood stuff.No serious structural engineer can re-do the NIST analysis.

Appeal to ridicule noted

Thus my suspicion that Shyman Sunder is a terrorist! He destroys the work of serious structural analysts!

Your opinions of peers is irrelevant when you cannot demonstrate a better alternative. It's particularly sad when the attempt fails before it's even typed on the computer screen.

 

[Heiwa]

AA. Question number one; does your model account for the effects of weakened structural members from the effects of elevated temperatures? Does your model account for the effects of thermal expansion and the lateral loads which it induced on connecting components?

I see no mention of either on your write up




BB. Except there's a problem which inherently affects the calculations you [supposedly] applied to the loading conditions. The model you use to base your calculations is incredibly simplified;

First off, the building was constructed on top of a substation which required the construction of three transfer trusses for the first 5 floors, these trusses carried the weight of the structure above it. Your model does not accurately represent this.

CC. Second, your sectional drawings do not accurately represent the varied beam spans which were part of the WTC 7 structural design. Your model assumes that all floor spans are the same; THEY ARE NOT (CLICK)... large floor sections were contingent of individual columns maintaining their integrity.

DD. Third your models do not consider either the effects of fire-induced damage or the long floor spans which would have magnified the effects of thermal expansion and therefore influenced the lateral loads applied to connections not designed for such loads.




EE. Your model assumes that the structural design of WTC 7 is the traditional post & beam construction, with a skeletal frame found in more traditional steel construction. This is not how WTC 7 was built; and you wonder why your aren't taken seriously?



That's quite an interesting statement coming from an engineer who has demonstrated that his modeling of both the towers and WTC 7 is not only oversimplified, but wrong. Surely I hope you think about your own faults before lashing out accusations of lousy work, however if you have no problem with being a hypocrite then by all means, please continue.




Appeal to ridicule noted


Your opinions of peers is irrelevant when you cannot demonstrate a better alternative. It's particularly sad when the attempt fails before it's even typed on the computer screen.

AA. Of course not - I only remove column 79 between floors 11/13 of an intact structure ... and the structure does not collapse. NIST clearly states that removal of a piece of column 79 alone causes collapse. I find it is not true. And the temperature inside WTC7 was so low that it did not affect the properties of 99% of the primary and secondary structural parts = my model is pretty good.

BB. It is as simple as the NIST model. What is down below floor 11 is of no importance - that structure there is intact all the time. Nothing can damage it.

CC. How do you know? Anyway, it is only the stress in the columns before/after removal of a part of column 79 that is of interest and they are as described.

DD. ???? You do not know what you are talking about! In FEA we only analyse, step by step, the structure as it is! We start with the intact structure, then there is one failure (a part of column 79 is removed) - we re-analyse (as I do) - and if there are further failures you have to re-analyse after each failure. In my model there is no further failure after step 1.

EE. ???? WTC7 was built very strong. And it would never completely collapse if a part of column 79 between floors 11/13 was removed! I show it. NIST does not.

Conclusion. The NIST WTC7 report is false. It is 100% disinformation or just propaganda or a combination of the two. The report mentions plenty of names/persons that allegedly participated to write it. Do these clowns really exist? And if they exist - did they concur with the report or just lent their names?

You know, Grizzly Bear: In the business of psy-ops every trick is allowed. In this case a scientific report which is like a basket that you try to boil of soup in.

Open your eyes, FFS.

 

[Pardalis]

The report mentions plenty of names/persons that allegedly participated to write it. Do these clowns really exist? And if they exist - did they concur with the report or just lent their names?

You can always contact them

http://www.nist.gov/public_affairs/contact.htm

You know... reality.

 

[T.A.M.]

And in not one of these ridiculous analogies are hundreds of tons of material left behind. There was physical evidence, now there is not.

This must be what you guys call debunking.

So lets get it straight then Red. Your issue is NOT WITH the use of other evidence to come up with a best theory in the absence of available Physical evidence. Your beef is with the fact that the physical evidence was removed, and not catalogued and kept for future investigation?

TAM

 

[Heiwa]

You can always contact them

http://www.nist.gov/public_affairs/contact.htm

You know... reality.

I have (incl. Sunder) + Comments, etc. They never reply! Confirms my suspicion that they do not exist. No real people can write such a rubbish report! And the structural damage analysis (sic) in it. Just fantasy! Hollywood.

Did you read my (Anders Björkman) Comments at the NIST web site? Top of the list. Compare then with the NIST report.

 

[dtugg]

Heiwa, you are leading the November Stundie finals. Congrats!

 

[jaydeehess]

If you read my article you see that NIST suggests that the structure collapses completely, if you remove column 79 between floors 11/13. Falling debris and other local failures of floor beams/girders connected to column 79 above floors 11/13 are irrelevant.

If you read the NIST report you will know that NIST does not state that an instant, magical removal of part of col 79 would result in the global collapse.

If you read the NIST report then you also know that your simplified structure does not represent the way WTC 7 was constructed either.

Its a pity we do not have any other Swedish engineers to compare you to. It really brings my estimation of your country's higher education system down, and I like Sweden. I have visited Stockholm. With you though I just keep going back to seeing the Wasa and knowing that it capsized and sank on its maiden voyage because the engineers of the time just ignored the physics they should have known at the time.

 

[jaydeehess]

So lets get it straight then Red. Your issue is NOT WITH the use of other evidence to come up with a best theory in the absence of available Physical evidence. Your beef is with the fact that the physical evidence was removed, and not catalogued and kept for future investigation?

TAM

I have tried to address both issues for RI.

However I do not think that saying he does not have an issue with the use of other evidence is true. He just is not willing to admit that there could be any that is as 'good' as having the actual pieces involved and that absent those pieces there is no way to come up with anything other than a speculative theory at best.

As for storage and catalogueing of every piece of steel, RI seems unwilling to go down the road od suggesting how this would have been accomplished, where?, how?, how much would it cost?

 

[Baylor]

Heiwa, you are leading the November Stundie finals. Congrats!

You means he's beating Ultima1. That's quite an accomplishment. I had my money on JihadJane's "no one claimed you can't crash a plane in d.c. building" whopper.

 

[Grizzly Bear]

AA. Of course not - I only remove column 79 between floors 11/13 of an intact structure... and the structure does not collapse.

There's your mistake, try incorporating calculations of how much the members exposed to heat would have expanded. Then calculate how much lateral force the expansion would have produced against the connecting components. How much force can a connection designed for vertical loading withstand from an a-typical lateral force? How much were the columns in and around the failure region affected by the heat induced weakening?

NIST clearly states that removal of a piece of column 79 alone causes collapse. I find it is not true. And the temperature inside WTC7 was so low that it did not affect the properties of 99% of the primary and secondary structural parts = my model is pretty good.

Your model is a misrepresentation of the structural design of the tower. Your diagram reads as a structural cross section one would expect to see of more traditional high rise construction. You can have as many things as you want or need correct, but you will never get an accurate model from deriving a result from a false comparison period.

The floor spans inside the building were not all the same lengths, as can be concluded from looking at the Typical Plan. No one quadrant; north, south, east, or west, shared the same kinds of floor spans. This is a very critical mistake of you to make..

CC. How do you know?

I know, because I've seen the Typical Plan layout of each floor. NIST provides it on a silver platter.

DD. ???? You do not know what you are talking about! In FEA we only analyse, step by step, the structure as it is! We start with the intact structure, then there is one failure (a part of column 79 is removed) - we re-analyse (as I do) - and if there are further failures you have to re-analyse after each failure. In my model there is no further failure after step 1.

As I alluded to already, if the model you start with fails to properly represent the actual design, then the results that are produced will carry absolutely no weight to them.

EE. ???? WTC7 was built very strong. And it would never completely collapse if a part of column 79 between floors 11/13 was removed!

This is subjective in that it is entirely contingent upon the design of the structure. IF WTC 7 were constructed more like this then yes I might expect only a localized failure. However WTC7 was built with certain areas in which a large section of each floor was contingent upon a single column. If I recall some columns inside WTC 7 were supporting as much as 2000 square feet of floor space. The effect of individual failures would be effectively magnified on adjacent load supporting members.

You know, Grizzly Bear: In the business of psy-ops every trick is allowed. In this case a scientific report which is like a basket that you try to boil of soup in.

Open your eyes, FFS.

Why does this remind me of all these claims that the government is omnipresent, Omnipotent, and omniscient, yet complete dunces at hiding their perfectly mastered plans and of such idiocy that laymen could spot the best defenses against discovery as if they are handed out on a silver platter?

 

[Pardalis]

I have (incl. Sunder) + Comments, etc. They never reply! Confirms my suspicion that they do not exist. No real people can write such a rubbish report! And the structural damage analysis (sic) in it. Just fantasy! Hollywood.

Did you read my (Anders Björkman) Comments at the NIST web site? Top of the list. Compare then with the NIST report.

I'm almost sorry I asked. I knew you were a special case, with the pizza boxes and all, but now you really are freaking me out.

No wonder the people at the NIST didn't respond.

 

[Jonnyclueless]

I have (incl. Sunder) + Comments, etc. They never reply! Confirms my suspicion that they do not exist. No real people can write such a rubbish report! And the structural damage analysis (sic) in it. Just fantasy! Hollywood.

Did you read my (Anders Björkman) Comments at the NIST web site? Top of the list. Compare then with the NIST report.

I believe they stated they would only address plausible things. Hence you not getting any response.

 

[Heiwa]

AA. There's your mistake, try incorporating calculations of how much the members exposed to heat would have expanded. Then calculate how much lateral force the expansion would have produced against the connecting components. How much force can a connection designed for vertical loading withstand from an a-typical lateral force? How much were the columns in and around the failure region affected by the heat induced weakening?

BB. Your model is a misrepresentation of the structural design of the tower. Your diagram reads as a structural cross section one would expect to see of more traditional high rise construction. You can have as many things as you want or need correct, but you will never get an accurate model from deriving a result from a false comparison period.

CC The floor spans inside the building were not all the same lengths, as can be concluded from looking at the Typical Plan. No one quadrant; north, south, east, or west, shared the same kinds of floor spans. This is a very critical mistake of you to make..

DD. However WTC7 was built with certain areas in which a large section of each floor was contingent upon a single column. If I recall some columns inside WTC 7 were supporting as much as 2000 square feet of floor space. The effect of individual failures would be effectively magnified on adjacent load supporting members.

Why does this remind me of all these claims that the government is omnipresent, Omnipotent, and omniscient, yet complete dunces at hiding their perfectly mastered plans and of such idiocy that laymen could spot the best defenses against discovery as if they are handed out on a silver platter?

AA. Heating some secondary parts (floor girders) does not induce much stress in the primary parts (columns). The whole structure just expands in all directions. The connections are really solid and will never break due to heat. It is just an invention by NIST.

BB. Not really. The figure is just a simplification. But it helps to understand the path of the forces. A load on a floor beam is carried to a floor girder and from there to a column and down to ground. VERY SIMPLE path.

It doesn't go from one girder to another.

CC. Irrelevant. Each innner column is supported by four floor girders/beams at every floor level. Evidently the column dimensions are adjusted for different floor areas it supports.

DD. Evidently the column is adjusted for that.

No, if you read the NIST report carefully, NIST really suggests that the whole structure was dependent on ONE only column, i.e. no. 79 (an inner core column connected to two other inner core columns and two wall columns) and that by removing a part of it ... POUFF ... the whole structure collapses incl. 23 other inner core columns (they all fail simultaneously!) = no redundancy. That statement is not proven anywhere (it is ridiculous) - like most of the the other findings, e.g. that you can model a part disconnected at both ends flying around (dropping down).

How can a part of a structure be ripped off at both ends by gravity forces?

Just by looking at big pieces of junk in the rubble you see that the fractures required to produce them were not done by gravity forces.

So why does NIST produce such a rubbish report? Easy! The staff lacks moral fibre and produces something that their political overloads can accept. So it can only become unscientific garbish. Quite sad, actually.

 

[Pardalis]

Conclusion. The NIST WTC7 report is false. It is 100% disinformation or just propaganda or a combination of the two. The report mentions plenty of names/persons that allegedly participated to write it. Do these clowns really exist? And if they exist - did they concur with the report or just lent their names?

So why does NIST produce such a rubbish report? Easy! The staff lacks moral fibre and produces something that their political overloads can accept. So it can only become unscientific garbish. Quite sad, actually.

You know Heiwa, you may have a difference of opinion on the NIST's findings, this is for real engineers to decide if your doubts have any merit, but each time you close a post with you "conclusion", it's always out there, I mean way, way out there. It just doesn't follow even from your own problems with the science of the report. You're jumping to an insane conclusion, whithout any proof, and without any reason to.

You start with maybe legitimate problems with the science, and then you jump to paranoid kooky conclusions. The "the report is flawed so therefore the people who made it must not exist" shtick is not helping your credibility, it's just plain freaky.

The burden of proof you expect form NIST should apply to your own accusations of foul play. You have to find evidence of foul play, and your own interpretation of the NIST report and how flawed it is isn't proof of a conspiracy.

 

[Heiwa]

The burden of proof you expect form NIST should apply to your own accusations of foul play. You have to find evidence of foul play, and your own interpretation of the NIST report and how flawed it is isn't proof of a conspiracy.

Topic is the NIST WTC7 report and I just found a serious error on page 90:

"WTC7 was prone to classic progressive collapse in the absence of debris impact and fire-induced damage when a section of Column 79 between Floors 11 and 13 was removed. The collapse sequence demonstrated a vertical and horizontal progression of failure upon removal of the Column 79 section, followed by buckling of exterior columns, which led to the collapse of the entire building."

No steel structure with 24 inner columns and 26+ wall columns (yes there are more) interconnected by solid beams at every 4 meters is prone to classic progressive collapse, whatever THAT is. Classic progressive collapse? A new invention of NIST! Has never taken place anywhere before.

And what kind of horizontal progression failures is NIST talking about. Buckling of 50+ columns? None found in the rubble!

And vertical progression of failures? Why would anything fail above? If you remove a support what's above just displaces downward. It doesn't fail.

Except in the NIST model. Parts everywhere are ripped apart at both ends and fly away in all directions - the NIST software keeps track of every failure and forces acting on completely loose parts and the pathes of the loose parts, when the model disintegrates into 10 000's of parts. Magic? No, just nonsense!

I asked NIST for details of this fantastic FEA software - to use it in analyzing structural damages in ship collisions - no reply of course. Such software does not exist!

The software NIST uses seems to be the ones used to animate Hollywood disaster movies. Thus little do with serious structural damage analysis.

Draw your own conclusions.

 

[funk de fino]

Classic progressive collapse? A new invention of NIST! Has never taken place anywhere before.

Now you are just flat out lying. It disgusting actually.

 

[Pardalis]

The software NIST uses seems to be the ones used to animate Hollywood disaster movies. Thus little do with serious structural damage analysis.

Draw your own conclusions.

Again, completely paranoid non sequitur.

 

[Grizzly Bear]

AA. Heating some secondary parts (floor girders) does not induce much stress in the primary parts (columns). The whole structure just expands in all directions.

However, you know full well that the effects would not be uniformly distributed throughout the structure at any one particular moment in time. Not every structural member is expanding or contracting at the same time or rate at any one given period of time. That is what makes your answer invalid.

The connections are really solid and will never break due to heat.

WTC 5 would tell you otherwise:

Link 1
Link 2

that your statement is a complete falsehood. However it doesn't require heat to fail a connection, if the connection isn't designed for the type of load it receives, it's at risk of failure.

It is just an invention by NIST.

No it is not... keep your paranoia to yourself please... the level to which you take it is... concerning, to put it lightly...

BB. Not really. The figure is just a simplification. But it helps to understand the path of the forces. A load on a floor beam is carried to a floor girder and from there to a column and down to ground. VERY SIMPLE path.

This is in principal true, however you treat the building as if the structural frame is the same throughout the building, or your model reads too simply. Either revise your model or clarify it, regardless you've demonstrated that your understanding of the construction is limited, too much so for the audience you're writing to.

Just by looking at big pieces of junk in the rubble you see that the fractures required to produce them were not done by gravity forces.

Connections are the limiting factors in the design allowables. If that's all your contention is based on, I'm afraid you've simply confirmed that failures in these components can, and do occur, and nothing more.

Topic is the NIST WTC7 report and I just found a serious error on page 90:
<snip>
No steel structure with 24 inner columns and 26+ wall columns (yes there are more) interconnected by solid beams at every 4 meters is prone to classic progressive collapse, whatever THAT is. Classic progressive collapse? A new invention of NIST! Has never taken place anywhere before.

This is very concerning coming from an engineer, and a spectacular display of paranoia. An invention of NIST? You never looked up the Ronin Point plaza or the Murrah Building have you? *Face palm*

 

[rwguinn]

Again, completely paranoid non sequitur.

Wait a minute--He may have something here.
The report was publisheed using Adobe, which is the exact same program used to publish Hollywood movie scripts.
In fact, it was likely written using Microsoft Word, or Word Perfect, which are the programs writers like Terry Pratchett, Tom Clancy, Gordon Dickson, and others use to write Fiction!
Damn--We're caught out!

 

[Heiwa]

Now you are just flat out lying. It disgusting actually.

We are talking 3D steel column/beam structures with correct joints. No classic total collapse, ever. Just local failures - some beams overloaded. No big deal!