OOS Collapse Propagation Model

[WilliamSeger]

The comment was directed at M_T who has an encyclopaedic collection of misrepresentations which includes that one. If you can prove that one wrong - go for it. I'm confident M_T will get the point - and almost certainly ignore it.

I don't think M_T reads my posts.

Never any doubt that he identified the mechanism (a) as "complicated" and (b) partly described it as one probable option. What are you disagreeing with the 85%

What are you bidding? 50-50? 85-15 the other way?

Remember the point - both sides making global claims.

Up-thread, M_T claimed that Bazant "didn't seem aware that the collapse progression mechanism some of us call 'ROOSD' existed." Since he clearly was, that claim is 100% false.

Then you say, "You opponents are wrong in several ways - the critical one being the false claim that he 'described' the mechanism." Since he did, I'll bid 100% on that one too.

 

[ozeco41]

Yes code concessions can occur and do occur in some cases. I don't think you should call her a liar and I do think the aggregate "code concessions" resulted in a less robust structure and pretty shabby egress and fire suppression systems... considering what turns out the be a design which rather easily can go runaway... in some catastrophe scenarios.

Maybe.

Why not?

she is deliberately making both false claims and partially true claims framed to present false implications which will mislead her audience to adopt an unbalanced viewpoint. Her objective is to persuade others to a false point of view by using words based trickery.

Near enough to lie for me. The intention is to mislead.

And the issue I contested was the claim that the code concessions - if there were any - were not valid - not legal. I see that you agree with me but are still trying to hedge your bets. And I've lost count of how many times I have responded to your assertions about designs at the ultimate limit collapse point. What are you suggesting should change?

The only idea I have thought of is to mandate that ultimate failure - way beyond code design parameters - should be by a "soft fail mechanism". Do you have any specific idea what you would like to see change. - In other words a forward looking positive approach rather than looking backwards with punitive liability in mind.

 

[ozeco41]

I don't think M_T reads my posts.

Up-thread, M_T claimed that Bazant "didn't seem aware that the collapse progression mechanism some of us call 'ROOSD' existed." Since he clearly was, that claim is 100% false.

Then you say, "You opponents are wrong in several ways - the critical one being the false claim that he 'described' the mechanism." Since he did, I'll bid 100% on that one too.

Let's leave it there:
- you are missing my point with the percentages;
- also my point with the false global claims;
- my other point that it is easy to quote mine for bits of example to prove either side; AND
- the overriding issue that wherever we discuss has no effect on anything currently before us for legitimate debate.

And - recall my final comment:

I'll stop or reduce my involvement on discussions which go nowhere and...
"simply rebut any errors - by either "side" - if and when they appear in ongoing discussion which interests me."
.

 

[WilliamSeger]

I'll stop or reduce my involvement on discussions which go nowhere and...
"simply rebut any errors - by either "side" - if and when they appear in ongoing discussion which interests me."

I'm more than ready to move on with whatever you wished to discuss next.

 

[ozeco41]

I'm not. You are one of the only posters in this 5 year thread that can see that.

There are a few - depending how you put the question. I've got some funny ideas which I have repeated many times. If I agree with you I say so. If I disagree I also say so. And I won't use false arguments to disagree with you where you are right.

Have you looked closely at the comments of other posters when these questions are put before them? Here we go again...

Yes. and I've put the same technical questions and met much the same nonsense.

BUT - as I have also said many times - I don't think you will get discussion whilst you frame it as questions rather than claims for discussion and "proof". Nor while you overtly attack the debating style of the members.

Hey guys, Is there anyone besides Ozeco or SanderO that can see that there is something not quite right about how David Benson, co-author of BLGB, perceived the collapse progression process of the WTC towers?

Is there anyone who can see that there is something not quite right about statements made by Bazant in the closure to BV, which is BL?

Ozeco, watch the responses. I've been asking variations of the same question for 5 years and I've always received the same responses without a single exception.

You are challenging the cultural and behavioural norms of the forum - what you describe as "memes". I don't think it is a worthwhile venture. Personally I would have fun identifying those "memes" - an interesting mental challenge in meta-process analysis. But doing so on this forum would not meet the Dale Carnegie standard of "Winning Friends and Influencing People".

If you can see there is something not quite right about the quotes of David Benson and in the quotes produced earlier from BL but others can't, then please remember that you are the exception within the JREF/ISF environment, not the rule.

I've no intention of conforming with either "Group Think" or "Don't Think".

Ozeco, you are honest enough to admit that you have never read BV, BL, and BLGB. Many of the other posters are not but you are.

I know from some of the comments you made that you have never read them. But I'll ask anyway...did you read those papers?

Many times when I need to. You are trapped in ancient history. I've read all of them. And I have recently limited my comments on them to the base assertion "The later papers by Bazant et al are wrong if and whenever they apply 1D simplification models to the WTC real event"

If not, on what basis do you make such claims about papers you have not read?

Same false premise. And note how carefully conditional I framed that assertion. It's a long time since I said "Bazant applies 1D approximations in such and such a later paper and he is wrong to do so." I remember that it was correct when I said it - maybe anything up to 5 years back - or I wouldn't have said it. BUT if I say it again now I will double check.

If ever the need to be so explicit arises in the future I wil once again read the relevant paper and confirm that I understand them.

My interest is in explaining WTC 9/11 engineering forensic matters. I'm not into the unarmed combat games of "win at any cost" nit-picking prove you wrong stuff. I abort from discussions once the objective becomes clearly "gotcha games". Several recent examples.

What choir? If you can see mistakes in BL and the Benson quotes, you are the exception to the JREF/ISF environment, not the rule. They are 'the choir', not you, and I will continue to point out their mistakes on this public forum with or without your permission to do so. That is why I reopened the thread: to record their responses just as I recorded those of David Benson.

I think I have a quartet - and your comments were a response to me.

 

[pgimeno]

Face it. B&Z was a good analysis for 9/13. It wasn't perfect.

You're talking about B&Z 2001.

WilliamSeager quoted from B&Z 2002. Different papers, even if same basis.

 

[ozeco41]

You're talking about B&Z 2001.

Of course I am. I said "Face it. B&Z was a good analysis for 9/13. It wasn't perfect." I will stand by that judgement - For any Professor and his PhD student to do such a good job in two days was IMO a great achievement. The credit was for the two days achievement. It makes it a far less dramatic achievement if you insist on taking the months later versions including the one from early 2002.

WilliamSeager [sic] quoted from B&Z 2002. Different papers, even if same basis.

So was I BUT I specifically avoided the "Addendum" -- "which arrived too late for publication as part of the paper"

That addendum shows how limited his understanding of the actual mechanisms was back in 2002. And he was already drifting off into the errors which characterise the later papers.

And I still say that his 9/13 effort was commendable. You seem to imply disagreement.

 

[Major_Tom]

There are a few - depending how you put the question.

Who? We can easily review the posts.


Who?

 

[Major_Tom]

Why not?

she is deliberately making both false claims and partially true claims framed to present false implications which will mislead her audience to adopt an unbalanced viewpoint. Her objective is to persuade others to a false point of view by using words based trickery.

Near enough to lie for me. The intention is to mislead.

Do you know who she is? She is the co-chair of...some committee. Do you know what that committee is?

 

[JSanderO]

OK this is going no where but he said she said and gotcha and when and what Mr B said.

There appears to be at this date, at least a general consensus that the floors both inside and outside the cores collapsed / were destroyed and by passed the columns which toppled from Euler instability. Column strength had nothing to do with the floor collapse nor could column strength prevent or arrest a runaway floor collapse.

There is no consensus about how the collapse initiated other than the notion that if the top section fell the columns had to have failed and were likely misaligned caused by some yet to be agreed upon mechanism.

In 1wtc before the top shows visible downward motion the antenna begins to sink into the structure and tip and there is a section or the SE facade which appears to buckle /move/bow inward.

+++++

INITIATION

It appears (please correct) that the IB of the south facade extends from the SE corner about 10 columns (300-310) then there are a few column not buckled and then perhaps more columns to the West that are buckled.... clearly lots of black charring on the floor all the way from east to west.

Is it possible for a 30+ foot section of the facade to bow without the building's steel frame being warped? Or were these facade columns simply pulled in and the rest of the facade and core frame remained "true"?

NIST's plate showing the bowing indicates the maximum bowing occurred at the face below where the hat truss outrigger is bearing (~ column 310) which is aligned with the east row of the core's perimeter.

The floor trusses from corner of the belt girder at column 310 to the SE corner columns 300 and 259 were bearing on an e-w transfer truss girder from bthe belt girder at core column 1000 to facade columns 243... which also was directly below am E-W hat truss outrigger.

It appears that the IB on the east side of the south face was a result of the hat truss losing bearing on the north side of the core at row 500, some at 600. This presented increased loads to the south side of the core via the hat truss perhaps leading to the buckling of col 1008 leading to the drop of the belt girder on the SE side of the core which may have exerted a lateral SE impulse to the belt girder structure and floor plates pulling the core perimeter columns to the SE misaligning them and leading to the top to drop and the progress floor collapse we agree to call GrandMa (;-))

It seems as if the top drop and collapse was not caused by the floor trusses in the SE corner pulling the facade in.

 

[Bravin Neff]

Hey guys, Is there anyone besides Ozeco or SanderO that can see that there is something not quite right about how David Benson, co-author of BLGB, perceived the collapse progression process of the WTC towers?

Is there anyone besides yourself that thinks something so forlorn and trivial is actually meaningful? When pressed on the issue, you dodge over to the "I'm just an anthropologist studying memes" charade. But when you let your guard down, you really do care very seriously about BLGB, don't you? I mean, to an unhealthy degree. You want to talk about that?

Its not your fault.

Is there anyone who can see that there is something not quite right about statements made by Bazant in the closure to BV, which is BL?

In this thread you were given detailed responses that, to date, you have ignored. Is there anyone who can see that there is something not quite right about your selective ignoring technique?

Its not your fault.

Its not your fault.

Ozeco, watch the responses. I've been asking variations of the same question for 5 years and I've always received the same responses without a single exception.

When you generalize so broadly that everything that fits inside the box of "not matching MT's fake anthropology schtick" is considered homogeneously alike - sure, I guess I would have to agree you haven't found a single exception.

How's the anthropology study going, by the way? Any new memes you can report on, or are the 2015 ones still the same as the 2007 ones?

Its not your fault.

Its not your fault.

Its not your fault.

 

[JSanderO]

Calling someone a LIAR means they willfully with intent chose to mislead. You can't possibly know Ms Regenhard's intention. You might know that her motive was to determine if there was issues with the fire code and or implementation of it. Understandably she had concerns that perhaps corners had been cut. A perfectly legitimate question to pursue.

 

[JSanderO]

Why are MT's statements under such scrutiny? Who the eff cares what MT says...

What's important is to determine what happened not who said what when and so forth. This quote mining "gotcha" stuff is a childish waste of time.'

DISCUSS THE MERITS OF HOW THE TOWER COLLAPSED. NOT THEORY or MATH.

It's OK to propose something and it may not turn out to be true or accurate. But smart people who are sharp observers and understand engineering and the structure SHOULD be able to come up with a pretty decent hypothesis or what happened. No proofs

Get real!

 

[Crazy Chainsaw]

Why are MT's statements under such scrutiny? Who the eff cares what MT says...

What's important is to determine what happened not who said what when and so forth. This quote mining "gotcha" stuff is a childish waste of time.'

DISCUSS THE MERITS OF HOW THE TOWER COLLAPSED. NOT THEORY or MATH.

It's OK to propose something and it may not turn out to be true or accurate. But smart people who are sharp observers and understand engineering and the structure SHOULD be able to come up with a pretty decent hypothesis or what happened. No proofs

Get real!

I know people refuse to read papers or understand the models, MT states Benson is
Wrong then posts a picture Gif proving he is right about D'Alembert's principal.

I am beginning to think this forum is full of people who have been arguing just
For the sake of personal EGOs.

It is becoming a total waste of time, oh a building could be designed to resist collapse,
Simply provide a mass shedding construction every six floors. That
Way the gravitational potential can never go runaway alway down the building.

 

[JSanderO]

I know people refuse to read papers or understand the models, MT states Benson is
Wrong then posts a picture Gif proving he is right about D'Alembert's principal.

I am beginning to think this forum is full of people who have been arguing just
For the sake of personal EGOs.

It is becoming a total waste of time, oh a building could be designed to resist collapse,
Simply provide a mass shedding construction every six floors. That
Way the gravitational potential can never go runaway alway down the building.

This is true... there is little to no interest in understanding the mechanisms of the destruction of the towers beyond some "broad stroke" concepts... no one will venture down to the next level.

It's pretty humorous really.

 

[Major_Tom]

It is becoming a total waste of time, oh a building could be designed to resist collapse,
Simply provide a mass shedding construction every six floors. That
Way the gravitational potential can never go runaway alway down the building.

Yes. There is a very simple lesson that could be learned. The Windsor Tower example shows how periodic barriers can help prevent runaway open floor space collapse all the way to earth.

 

[Major_Tom]

This is true... there is little to no interest in understanding the mechanisms of the destruction of the towers beyond some "broad stroke" concepts... no one will venture down to the next level.

It's pretty humorous really.

Humorous or tragic or both. But it gets worse...


I do not think anyone will disagree that of all the collapse features of the WTC towers, the collapse progression modes are the single grossest feature. If one fails to notice the single largest feature of the collapses, it is safe to say they won't notice the more detailed, nuanced features of the collapse initiations of either tower.

The progression features are gross, whereas the initiation features are subtle. If a person cannot read or understand the existing literature on the WTC collapse progression modes, they will not be able to understand any of the written technical history on the WTC collapses. If one fails to understand the collapse progression modes, or the written technical history on the collapse progression modes, such a person will be confused about everything else related to the WTC collapses.

When I watch people who are unable to read a paper, or unable to identify a collapse front, or unable to tell fact from fiction concerning claims or literature on the WTC collapse progression modes, there is no way that same person can understand either the visual or written records of the collapse initiation modes of the same buildings. For this reason the interpretation of what ones sees in the visual record and the interpretation of what one reads on the WTC collapse progressions serves as an excellent barometer to judge how much or how little one knows about pretty much everything related to the collapses of WTC1 and 2.

And the truth is that not much is known about them. In order to avoid this embarrassing fact, people tend to fake or embellish the written and visual records to make them look more consistent and authoritative than they really are. In forums on this topic and in threads like this, you are watching that embellishment in action. You are watching how they are embellished.


And that, to me, is interesting. That is the only reason I participate in a thread like this.

 

[WilliamSeger]

Why are MT's statements under such scrutiny? Who the eff cares what MT says...

I thought M_T was the one sane voice guiding you through understanding what happened? Anyway, my answer to your question is that it seems to me M_T is more interested in creating false memes than he is in collecting them.

What's important is to determine what happened not who said what when and so forth. This quote mining "gotcha" stuff is a childish waste of time.'

The section of BZ 2002 that I quoted is certainly not "quote mining" and it is relevant to both what happened and who said what when.

DISCUSS THE MERITS OF HOW THE TOWER COLLAPSED. NOT THEORY or MATH.

Making my best guess at what you mean by "merits of how the tower collapsed," than as one who believes that I can't do one without the other, may I say I'm rather offended by your command.

It's OK to propose something and it may not turn out to be true or accurate. But smart people who are sharp observers and understand engineering and the structure SHOULD be able to come up with a pretty decent hypothesis or what happened. No proofs

Get real!

Yet when I quote you a section of BZ 2002 that does exactly that, you call it "childish."

 

[Bravin Neff]

In forums on this topic and in threads like this, you are watching that embellishment in action. You are watching how they are embellished. And that, to me, is interesting. That is the only reason I participate in a thread like this.

That is pretty clearly the least plausible reason you participate in a thread like this. Please allow me to quote myself:

The JREF/ISF debunking crowd certainly doesn't help with its tough-on-truthers style, but that cannot be the reason you insist your mission is that of the anthropologist, recording "debunking subculture memes" and insisting you are merely documenting things that to any casual observer are so forlorn, the real motives emerge between the lines despite the pretense.

Frankly I find that to be the real puzzle - why your motivation is given such a pass. The bottom line is that a few folks hurt your feelings, didn't they? Someone owes you an apology, don't they? Probably Ryan Mackey does, doesn't he? It seems the list of folks that ought to address your grievances is the same you constantly cite under the guise of some "meme" they allegedly got wrong, "memes" so trivial they cannot possibly warrant the deep anthropological mission of debunking-subculture-meme-documenter you pretend to be on.

I propose an M_T apology thread. I think it will help everyone.

 

[JSanderO]

For sure we can't see inside the tower to know what is going on. We can only see what is coming out and where... smoke.. and different colored smoke perhaps. We can see some facade damage, the IB and the antenna motion and the flames on various floors. So there is not much to work with aside from the structural information about the building and the contents on the floors (if known).

We do know from empirical tests how building materials perform under heat stress. We don't know how much jet fuel burned inside, where it burned and what else burned. We can make educated guesses. The same goes for the loss of fire proofing on structural members. We can't know how much was lost or where it was lost or even HOW it was lost. BANG it falls off? Maybe.

I find it very "humorous" that with respect to 7wtc... we are told by NIST that heat caused beam and girder explansion and "distortion"... ie lateral movement or distortion of the frame. These were very ROBUST steel sections that "warped".

Yet when it comes to the twin towers NIST didn't bother with the bracing beams of the core "warping" from heat and possibly (probably?... maybe?) destroying the integrity of the twin tower cores.

Of course one would have to consider that some lateral RESTRAINT had been removed in the plane strike zones when the core columns were severed. Into this zone of no restraint... the frame could possibly (probably??? maybe???) be pushed. And if that was a "process"/"mechanism" it would lead to column end mis alignment and loss of aggregate capacity of the core.... local column "loss".. and probably/possible? local floor collapses within the core.

Do we even understand what would happen to the 4 36' columns above the severed columns? Do thy just hang there? Held by the slab and the bracing beams? or do they drop and break away at the hat truss? Do the floor areas around those columns fracture and break free and drop? Or just "sag"?

The top drop took 1.5 hrs or so... what was the process going on which was "eroding capacity"? Surely it was a progressive loss of capacity... Was it column weakening from heat? or column misalignment from heat? or both? How does heat mis align a column?

Did the facade lose capacity from heating? If the core was not terribly compromised would the facade buckle, the floors collapse with it leaving the core standing?

Doesn't the sagging truss narrative imply an reasonably sound core? Were the upper core columns dragged along with the floors and the collapsing facade... ie the top was most "intact" and dropped. Wouldn't that mean all the coupled core columns would show obvious buckling in the debris... something like 40 buckled core columns from the strike zone?

Go for it!