Total Building Collapse from a Single Column Failure

[ozeco41]

Yeah I realize the OP topic is much broader... perhaps I should be smacked for leaving that out

yours is the least sin recently posted for "off topic"

And... I noticed... if it wasn't wasn't about this "connection failure" quibble there wouldn't be much to discuss. The summary is he doesn't believe that "single column failure" or fire can lead to a full on collapse and that's final....

There is nothing legitimate to discuss until T Sz accepts his burden of proof and puts his detailed claim in a proper context.

However many members enjoy playing "off topic whack a mole". And Tony's moles are (1) multiple; plus (2) easy to "whack".

As with the previous incidents that fatal error kills the debate before you ever reach the distraction over when bolt "A, B or C" failed first....

Yes. The status of Tony's claims AFAICS is unchanged from two years back. His base assumptions of the technical context for all these details are "not proven". So his claim is not "made out" to prima facie standard. Therefore there is nothing to discuss till he completes his argument.

It's why I was distinguishing the quibble' relevance... it could be relevant if we were talking about practical building code implementations, sure. But with "CD" assumptions that have been repeated over the years it's little more than a distraction because it's nothing short of an ambiguous diversion with no link to said alternate "theory".

There is no alternate. Never has been.

But then I'm obviously preaching to the Choir by saying all this.

The foundations of the argument are missing or false. So I'll sing bass - that's usually where the foundations are.

 

[Animal]

So I'll sing bass - that's usually where the foundations are.

And meanwhile.....troofers will continue to sing falsetto.

 

[ozeco41]

And meanwhile.....troofers will continue to sing falsetto.

I no longer have the vocal flexibility - and far too late for the surgical procedure.

 

[Newtons Bit]

More blah, blah, blah, blah blahbity blah, blah, blah, blah. Like I have been saying about the commenters here. Your comments remind me of the disingenuous "nothing to see here" line. If you are actually an engineer you are violating your ethics.

File a complaint with the Board.

 

[Porkpie Hat]

Maybe I'm missing something but reading through this discussion I see a focus on structural components and a connection with regards to the behaviour of those components during a heating cycle and how it affects that specific connection.

Now it seems to me that those components and that connection did not exist in isolation to the surrounding structure which was also subjected to heating/cooling cycles which would have affected the connections of many components before/after/during the time this specific example was in play.

Can we isolate this example and allow it to exist without consideration of the whole surrounding it?

And what about cooling cycles?

I see nothing mentioned about cooling cycles yet as a metal fabricator I utilize both the heating and cooling cycles, with a stronger emphasis on cooling, in order to understand how to facilitate things like the heat straightening of piping and structural materials in order to be in compliance with stated tolerances.

What am I missing??

 

[LSSBB]

Maybe I'm missing something but reading through this discussion I see a focus on structural components and a connection with regards to the behaviour of those components during a heating cycle and how it affects that specific connection.

Now it seems to me that those components and that connection did not exist in isolation to the surrounding structure which was also subjected to heating/cooling cycles which would have affected the connections of many components before/after/during the time this specific example was in play.

Can we isolate this example and allow it to exist without consideration of the whole surrounding it?

And what about cooling cycles?

I see nothing mentioned about cooling cycles yet as a metal fabricator I utilize both the heating and cooling cycles, with a stronger emphasis on cooling, in order to understand how to facilitate things like the heat straightening of piping and structural materials in order to be in compliance with stated tolerances.

What am I missing??

You're not missing anything. It's other folks who refuse to include the points you made concerning the collapse. The kicker is one of their arguments is based on NIST missing an inch in their analysis.

 

[Porkpie Hat]

You're not missing anything. It's other folks who refuse to include the points you made concerning the collapse. The kicker is one of their arguments is based on NIST missing an inch in their analysis.

Exactly, one inch is a system that was subjected to the heating and cooling of how many components!

No offense to engineers out there, but I`m reminded of the many, many times I`ve sat in an engineers office saying, `dude, I can`t do that because...`, and have that engineer not get it due to the fact that he`s looking at the issue in isolation and not understanding the effect over the big picture.

 

[tsig]

so then no comment on how the explosives got in the building in the first place?

first things first kiddo.

You didn't see his detailed explanation for how the CD's got there? Here I'll reproduce it for you:

blah, blah, blah, blah blahbity blah, blah, blah, blah.


Now how can you argue with that?

 

[ozeco41]

...Can we isolate this example and allow it to exist without consideration of the whole surrounding it?...

That is the fatal issue which Tony Sz has been reminded of many times over several years. He persists in arguing about structural details as if the central few elements of structure were the only bits affected by heat and the surrounding structure was not heat affected despite the extensive raging fires.

The "confusion" about the one inch is even sillier. NIST assumed that for something to fall off a seat it has to move 1/2 the seat width. The seat was 11" wide THEREFORE something had to move 5.5" to fall off. Then they found the seat was 12". (Actually it was a truther nit picker who found the 1" discrepancy and thought it meant something.) So a lot of folks who cannot read/did not read NIST got the explanation arse about and said "Five and a half inches wont move it off the seat". Wow! 5.5 was what it would take to drop off an 11" seat, the maths too hard - it would be 6" for a 12' seat; 6.5 for a 13" seat. Half the seat width whatever that width was. And that begging the question as to whether the "half width to fall off" assumption was valid. That's the core element of that "one inch discrepancy" issue - sure there are more details but essentially the problem arises from reading NIST's causality backwards.

...And what about cooling cycles?

I see nothing mentioned about cooling cycles yet as a metal fabricator I utilize both the heating and cooling cycles, with a stronger emphasis on cooling, in order to understand how to facilitate things like the heat straightening of piping and structural materials in order to be in compliance with stated tolerances.

What am I missing??

You have hit the key weakness of T Szamboti'e argument. I and a few others identified it a couple of years back. Many prefer to argue the details as if Tony's claim is somehow valid - and ignoring that key issue.

The claim isn't worth discussion until Tony accepts his burden of proof and shows either that his assumption is correct OR that it doesn't affect the conclusion. Until he does that his claim is wrong for the reason you and several others of us have identified.

So it is a classic "forests v trees" situation Alternatively "When you are up to your arse in alligators it is easy to forget that the objective was drain the swamp"...

...and, yes, some engineers are very prone to it.

 

[Porkpie Hat]

The "confusion" about the one inch is even sillier. NIST assumed that for something to fall off a seat it has to move 1/2 the seat width. The seat was 11" wide THEREFORE something had to move 5.5" to fall off. Then they found the seat was 12". (Actually it was a truther nit picker who found the 1" discrepancy and thought it meant something.) So a lot of folks who cannot read/did not read NIST got the explanation arse about and said "Five and a half inches wont move it off the seat". Wow! 5.5 was what it would take to drop off an 11" seat, the maths too hard - it would be 6" for a 12' seat; 6.5 for a 13" seat. Half the seat width whatever that width was. And that begging the question as to whether the "half width to fall off" assumption was valid. That's the core element of that "one inch discrepancy" issue - sure there are more details but essentially the problem arises from reading NIST's causality backwards.

Give me an oxy/acetylene torch with a rosebud and 8 hours and I'll get that thing to drop regardless of dimensions (almost).

My own understanding of this issue is based solely on the practical experience of having to make steel bend (literally) to my will rather than the theoretical experience of not having to worry about how the steel will behave when an inexperienced welder decides to forego the need to spread the heat evenly (or a lazy welder who doesn't want to move his machine around dragging cables) resulting in a minimization of distortion.

In other words, let the engineer worry about deflection and I'll handle the issue of distortion

 

[Animal]

That is the fatal issue which Tony Sz has been reminded of many times over several years. He persists in arguing about structural details as if the central few elements of structure were the only bits affected by heat and the surrounding structure was not heat affected despite the extensive raging fires.

The "confusion" about the one inch is even sillier. NIST assumed that for something to fall off a seat it has to move 1/2 the seat width. The seat was 11" wide THEREFORE something had to move 5.5" to fall off. Then they found the seat was 12". (Actually it was a truther nit picker who found the 1" discrepancy and thought it meant something.) So a lot of folks who cannot read/did not read NIST got the explanation arse about and said "Five and a half inches wont move it off the seat". Wow! 5.5 was what it would take to drop off an 11" seat, the maths too hard - it would be 6" for a 12' seat; 6.5 for a 13" seat. Half the seat width whatever that width was. And that begging the question as to whether the "half width to fall off" assumption was valid. That's the core element of that "one inch discrepancy" issue - sure there are more details but essentially the problem arises from reading NIST's causality backwards.

Another is the troofer claim of how far the beams could have expanded. They have locked on to the beam closest to Col 79 with the claim that it could not have pushed the girder the 6 inches. They fail to acknowledge that the beams further away could have pushed the girder more and that the closest beam could have expanded more due to external bracing and also uneven heating of the beam.

You have hit the key weakness of T Szamboti'e argument. I and a few others identified it a couple of years back. Many prefer to argue the details as if Tony's claim is somehow valid - and ignoring that key issue.

There are not a lot of troofers left to play whack a mole.....it is only the hard core fanatics like TS that a) haven't gotten banned or b) haven't finally come to grips with reality.

The claim isn't worth discussion until Tony accepts his burden of proof and shows either that his assumption is correct OR that it doesn't affect the conclusion. Until he does that his claim is wrong for the reason you and several others of us have identified.

So it is a classic "forests v trees" situation Alternatively "When you are up to your arse in alligators it is easy to forget that the objective was drain the swamp"...

...and, yes, some engineers are very prone to it.

 

[LSSBB]

Give me an oxy/acetylene torch with a rosebud and 8 hours and I'll get that thing to drop regardless of dimensions (almost).

My own understanding of this issue is based solely on the practical experience of having to make steel bend (literally) to my will rather than the theoretical experience of not having to worry about how the steel will behave when an inexperienced welder decides to forego the need to spread the heat evenly (or a lazy welder who doesn't want to move his machine around dragging cables) resulting in a minimization of distortion.

In other words, let the engineer worry about deflection and I'll handle the issue of distortion

Variance of "As Built" from design is another major elephant in the room, and not being discussed by our valiant NIST windmill tilters.

 

[Porkpie Hat]

Variance of "As Built" from design is another major elephant in the room, and not being discussed by our valiant NIST windmill tilters.

Oh come on!

As built and latest revision are ALWAYS the same!

(And designers are always on top of that...)

 

[Animal]

Oh come on!

As built and latest revision are ALWAYS the same!

(And designers are always on top of that...)

And of course "As built" and actual conditions are ALWAYS the same too!

 

[Porkpie Hat]

And of course "As built" and actual conditions are ALWAYS the same too!

Of course they are!

I love watching the tail lights of a heavy hauler leaving our yard and hearing someone whisper, "did you do as builts, because I know I didn't!".

 

[LSSBB]

Oh come on!

As built and latest revision are ALWAYS the same!

(And designers are always on top of that...)

The overarching issue, and one beaten to death endlessly and misunderstood fully by those arguing this trivia, is "simulation". NIST performed "simulations" in order to establish possible mechanisms for collapse initiation.

Here is a reference for you regarding "simulation":

http://www.modelbenders.com/encyclopedia/encyclopedia.html

I'd like to highlight a passage right from the start of that article:

Definition. Simulation is the process of designing a model of a real or imagined system and conducting experiments with that model. The purpose of simulation experiments is to understand the behavior of the system or evaluate strategies for the operation of the system. Assumptions are made about this system and mathematical algorithms and relationships are derived to describe these assumptions - this constitutes a "model" that can reveal how the system works.

The interior state of the building is unknown. Assumptions must be made. The end result in this case is already known: The building collapsed. NIST is trying to find a possible path for the collapse. What our NISTerical posters are criticising is minor details of these assumptions, and claiming fraud by NIST. As if NIST was including in the possible outcomes of their analysis, the supposition that the building could not collapse. Yet the building did indeed collapse. NIST had already outright rejected any causative mechanism that did not match fires and damage from adjacent collapses, so they were trying to determine how fires and damage from adjacent collapses initiated the observed collapse.

So, how could it possibly be fraud to manipulate the assumptions in their model to obtain a collapse, when that is what their model always must result in to be valid for their intended scope?

 

[DGM]

So, how could it possibly be fraud to manipulate the assumptions in their model to obtain a collapse, when that is what their model always must result in to be valid for their intended scope?

Because they didn't conclude it was a controlled demolition. Anything short of that has to be fraud.

Religion is funny that way.

 

[Justin39640]

The overarching issue, and one beaten to death endlessly and misunderstood fully by those arguing this trivia, is "simulation". NIST performed "simulations" in order to establish possible mechanisms for collapse initiation.

Here is a reference for you regarding "simulation":

http://www.modelbenders.com/encyclopedia/encyclopedia.html

I'd like to highlight a passage right from the start of that article:



The interior state of the building is unknown. Assumptions must be made. The end result in this case is already known: The building collapsed. NIST is trying to find a possible path for the collapse. What our NISTerical posters are criticising is minor details of these assumptions, and claiming fraud by NIST. As if NIST was including in the possible outcomes of their analysis, the supposition that the building could not collapse. Yet the building did indeed collapse. NIST had already outright rejected any causative mechanism that did not match fires and damage from adjacent collapses, so they were trying to determine how fires and damage from adjacent collapses initiated the observed collapse.

So, how could it possibly be fraud to manipulate the assumptions in their model to obtain a collapse, when that is what their model always must result in to be valid for their intended scope?

Tony and Gerrycan need to read this part over and over:

However, problems of interest in the real world are usually much more complex than this. In fact, they may be so complex that a simple mathematical model can not be constructed to represent them. In this case, the behavior of the system must be estimated with a simulation. Exact representation is seldom possible in a model, constraining us to approximations to a degree of fidelity that is acceptable for the purposes of the study.

 

[Porkpie Hat]

The overarching issue, and one beaten to death endlessly and misunderstood fully by those arguing this trivia, is "simulation". NIST performed "simulations" in order to establish possible mechanisms for collapse initiation.

Here is a reference for you regarding "simulation":

http://www.modelbenders.com/encyclopedia/encyclopedia.html

I'd like to highlight a passage right from the start of that article:

Great article for explaining modelling to laypeople (myself included)!

The interior state of the building is unknown. Assumptions must be made. The end result in this case is already known: The building collapsed. NIST is trying to find a possible path for the collapse. What our NISTerical posters are criticising is minor details of these assumptions, and claiming fraud by NIST. As if NIST was including in the possible outcomes of their analysis, the supposition that the building could not collapse. Yet the building did indeed collapse. NIST had already outright rejected any causative mechanism that did not match fires and damage from adjacent collapses, so they were trying to determine how fires and damage from adjacent collapses initiated the observed collapse.

So, how could it possibly be fraud to manipulate the assumptions in their model to obtain a collapse, when that is what their model always must result in to be valid for their intended scope?

Great point and one that I've completely missed in the past.

Really it should be quite obvious to me as by the time I get drawings the modelling and FEA's have been done and had customer approval yet we sometimes have elements that weren't presented in models because they simply weren't anticipated. At this point we as a company are required to prove our initial model willperform as per our clients expectation by using the as built information as input for proofing the design.

I realise the issue of a failure requires reverse engineering to a large degree so isn't fully equivalent to the engineering and fabrication stages of a project.

 

[LSSBB]

Because they didn't conclude it was a controlled demolition. Anything short of that has to be fraud.

Religion is funny that way.

Yeah, and my point was this: NIST came out and said they wouldn't consider controlled demolition, so how could aspects of building a simulation that doesn't consider an obvious controlled demoliton conclusion that the building could not collapse, possibly be fraud?