WTC7 and the girder walk-off between column 79 and 44

[Robrob]

Hence why they didn't need to test for explosives either.

Or dustification beam residue.

 

[Tony Szamboti]

How would they know this unless they spent countless hours testing? They should have left no stone unturned, right?

You are going from one extreme to the other. That is a sign of not having a good argument.

Obviously NIST was making an extraordinary claim by saying the fireproofing that was on the other side of the building behind the central core and several stories above the debris field was knocked off due to vibration or flexing. They needed to provide some level of substantiation that it was possible. They didn't and I think the reason no testing was done here was that the test would not support the contention being made.

 

[Tony Szamboti]

Looks like lots of SFRM was missing in this shot.....

[qimg]http://i24.photobucket.com/albums/c23/JPPics/9-11/FloorTrusses-FallenSFRMmissing.jpg[/qimg]

Nobody is saying the SFRM would not be knocked off at the impact side. Are you paying attention?

 

[Justin39640]

Nobody is saying the SFRM would not be knocked off at the impact side. Are you paying attention?

Not many doubt all of the SFRM in the building may have had big issues.

 

[NoahFence]

You are going from one extreme to the other. That is a sign of not having a good argument.

Obviously NIST was making an extraordinary claim by saying the fireproofing that was on the other side of the building behind the central core and several stories above the debris field was knocked off due to vibration or flexing. They needed to provide some level of substantiation that it was possible. They didn't and I think the reason no testing was done here was that the test would not support the contention being made.

See, this is where you and reality part ways. It was not an extraordinary claim. it was common sense it was obvious that wasn't worth looking into. that the fireproofing would fall off it's not surprising in the least.

 

[ozeco41]

Thanks Oz. ..

Not a problem.

...I'll never lose sight of the real situation and as you understand, I'm playing in their realm for the moment using Tony's logic, calculations, and numbers...

Both points understood.

...I would really like an answer from Tony or Clayton showing me how I am wrong when I arrived at my result using Tony's own numbers and logic. A result that shows the perimeter wall (or walls) should have failed and collapsed.

There are several of my questions also waiting in the queue - going back a couple of thousand posts. So far Tony has only moved half a step in acknowledging the truth of the big issues I raised in my first couple of posts in the thread. And that was on the OP - before this derail started.

So you may be in for a long wait.

 

[DGM]

You are going from one extreme to the other. That is a sign of not having a good argument.

Almost like saying all the fire-proofing had to be removed.............................

 

[Tony Szamboti]

Ok, not a full 0 height drop situation, as the columns were already compressed, but certainly with a dynamic component which made the load equivalent to something between 1 and 2 times the static one. Load redistribution implies movement, do we agree on that?



That needs proof. A bare assertion doesn't cut it. Can you point out the redistributed loads that NIST shows on the east and west wall columns, indicating why they are not enough?



It's your assertion. You defend it.

NCSTAR 1-6 page 300 to 304 shows the additional loads put on the east and west walls after impact were about 7% more than their original load and 30 to 35% more on top of that after the alleged south wall failure.

These columns had a 5.00 to 1 factor of safety against gravity. So they were originally only loaded to 20% of their capacity. The NIST after impact and after south wall failure loads would then be

20% x 1.07 x 1.35 = 29%. So even after impact of the north face and alleged south wall failure the NIST report shows they still had a factor of safety above 3.00 to 1.

The NIST report does not make a case for failure of the east and west perimeter walls. Unfortunately, this just sails right over the heads of most.

 

[Clayton Moore]

Nobody is saying the SFRM would not be knocked off at the impact side. Are you paying attention?

You and Christopher7 are wasting your time.

These people don't give a crap about the truth. You deserve a better audience. An audience who will listen to the points you make and tell their friends.


I can handle it from here.

 

[DGM]

You and Christopher7 are wasting your time.

These people don't give a crap about the truth. You deserve a better audience. An audience who will listen to the points you make and tell their friends.


I can handle it from here.

So, what he needs is obedient sheep.


I bet that last post of his really convinced you.

 

[Oystein]

...
20% x 1.07 x 1.35 = 29%. So even after impact of the north face and alleged south wall failure the NIST report shows they still had a factor of safety above 3.00 to 1.
...

Since the impact did not only sever columns but also affect lateral supports in many ways, there simply is no telling what the overall "factor of safety" was after impact, and much less what the "factor of safety" was fpr subassemblies and individual members.

In a nutshell, designed-for "factor of safety" is only applicable to the as-designed, undamaged and stressed within its designed-for envelope assembly.
Once you slam a plane through it, all those considerations are moot. For example, with floors trusses not providing lateral support but instead imposing a lateral load (by sagging, or by being attached to out-of-plumb columns on the other side) outside the design envelope, how can you expect columns to have any "factor of safety" at all?

 

[Animal]

Since the impact did not only sever columns but also affect lateral supports in many ways, there simply is no telling what the overall "factor of safety" was after impact, and much less what the "factor of safety" was fpr subassemblies and individual members.

In a nutshell, designed-for "factor of safety" is only applicable to the as-designed, undamaged and stressed within its designed-for envelope assembly.
Once you slam a plane through it, all those considerations are moot. For example, with floors trusses not providing lateral support but instead imposing a lateral load (by sagging, or by being attached to out-of-plumb columns on the other side) outside the design envelope, how can you expect columns to have any "factor of safety" at all?

You expect TS to face reality? His cult would never allow that.

 

[A W Smith]

http://www.structuremag.org/article.aspx?articleID=457

It is important to note that the ASTM E119 test procedure was developed in 1918, and although construction types and building contents have changed over the years, with the exception of a few minor refinements, the basic ASTM E119 overall test criteria has not changed. ASTM E119 is a standardized test method, which provides a means by which the performance of one material can be compared with that of another, under very defined conditions.
Many designers are under the impression that if an assembly on a project site is sprayed in accordance with a UL tested two-hour assembly, that the structure will remain intact for two hours, sustaining little or no damage. This is not necessarily true. How well an actual structure performs relative to the design assembly greatly depends on how closely the fire mimics the ASTM test standard, the actual condition of restraint, and the amount of fireproofing actually applied to the steel. Unfortunately, the amount of fireproofing required to properly protect a building is the subject of some debate.

http://www.nytimes.com/2001/12/14/nyregion/14TOWE.html

But the effectiveness of the very material installed in the towers is the subject of much debate among experts and competitors. The spray-on fireproofing chosen by the Port Authority was an early replacement for the asbestos-based materials that were eventually banned.
A competitor whose own cement- like product came to dominate the industry says the material used on the trade center did not stick well and was prone to deterioration.
Lawrence Shapiro, a marketing director at W. R. Grace & Co., said the fiber-based fireproofing — especially the early asbestos-free versions — never had the strength of the cement-like fireproofing that Grace produced.

Was the bond sufficient?

But according to the chairman of the company that made the fireproofing, a problem arose at the start. James Verhalen, chairman of United States Mineral Products of Stanhope, N.J., said the steel had been allowed to rust during storage.

Did it stay on? even during construction?

A review of the history of the buildings shows that even as the steel columns first rose into the sky, problems arose. Wind-driven rains stripped the fireproofing from the framework it was meant to protect, and construction workers had to improvise dams and diverters to channel the water away. The workers then reapplied the fireproofing.

 

[alienentity]

Tony, perhaps you need to reconsider the blast pressure of the plane contents and fuel/air explosions on the SFRM. The picture I included shows that the impact of the plane completely removed any SFRM in the area directly in the path of the plane. Now, are you contending that the plane simply stopped at the initial impact point and no forces acted on the rest of the SFRM on the impact floor?
This would make no sense, in fact it would be highly illogical.

Clearly, fireballs and a large amount of plane debris exited WTC 2, for example, completely on an opposite side of the building from the impact area. That demonstrates a tremendous amount of velocity for the plane debris.

The SFRM was never designed to stay bonded under those conditions, nor would it be expected to. Therefore it is a reasonable assumption to predict that a fairly large amount of it would be dislodged under these conditions, throughout the impact floors.

This also means that the original fire rating of the columns and floor systems would not be valid. It would NOT be a reasonable assumption to claim that it would be.

The idea that, through increased loads on the remaining columns and through loss of SFRM and the observed heavy fire conditions, the columns would fail, is a very sound idea indeed. In fact it simply cannot be taken off the table, so to speak, but instead remains the scenario with the most evidentiary support.

Your main error, along with apparently all your supporters in the 9/11 Truth movement, is not that you consider alternative ideas about the collapses of the towers. It is that you incorrectly eliminate the plane impacts and fires as sufficient to cause the collapse of the towers - essentially you treat this possibility as zero.
It would be much more constructive to simply allow that it WAS possible they could have collapsed that way, even while arguing in favour of another hypothesis. That way you don't put yourself in an intellectually or logically absurd position, as you are now doing.

Before you issue further denials of the force of plane impact, reconsider the case of the Pentagon crash, where the disintegrated plane mass not only entered a heavy, reinforced concrete building, but created an exit hole far into its interior! (ETA corrected)
Surely nobody here is going to argue that the pressures required to do that are not enormous and if concrete could be destroyed it is obvious that SFRM would not stand a chance if subjected to these kinds of forces.

 

[alienentity]

I think most truthers forget or are just unaware that skeptics ARE considering the various demolition hypotheses put forward.
The problem is that you can't prove a negative, so even while most of us are highly skeptical of the various truther claims due to lack of hard evidence, we can't say 100% that these claims shouldn't be at least entertained.
Sure, thermite, nanothermite, conventional explosives are out there as possible candidates for the collapse of the towers, although it appears highly unlikely that they were responsible in light of the fact that we had the plane impacts, fireballs, and large fires.
Tony Szamboti's current (and historical) approach appears to be that, by studying the collapse behavior one can ELIMINATE these plane impacts, fireballs and large fires as having ANY possible causality and infer some unspecified controlled demolition. This is simply illogical and irrational, from a skeptics point of view.

Personally, if I had to rate each possible cause on a scale of 1 to 10 for likelyhood based on direct, positive evidence, the plane impact, fireball and large fire hypothesis is far and away the most likely and the closest to a '10 out of 10'.
I'm not saying that thermite as a cause rates a zero, but it wouldn't be far off that number. I've looked carefully at the evidence and claims put forward, and they're 100% anecdotal and speculative - there simply is no hard evidence of thermite.
I don't think I'm being unfair about this because IF there were hard evidence, I think I'd accept it at face value.
None of Tony's arguing about the details of the damage is going to reduce the probability of the conventional understanding of causality to ZERO. Not with me, nor other skeptics, nor (I think it's safe to say) any major engineering organization or collection of engineers who happen to study the issue at length.

Truthers are,thru their various rhetorical techniques and rhetorical distractions, are out of sync with most of us in that regard and will remain that way until they stop trying to prove a negative.

IMO their cause is ultimately futile and will not succeed.

 

[pgimeno]

Well said, AE. One of the logical fallacies that Tony makes is claiming that NIST's is the only possible explanation for a collapse caused by fire, because given the absolute lack of hard evidence, and even of a plausible complete hypothesis that matches the observables to enough degree, his last resort is to go the "prove a negative" route. So his argumentation is that by disproving NIST's explanation, he has refuted all possibilities of collapse by fire and therefore the only remaining explanation is intentional demolition, of which there's not an iota of evidence.

 

[pgimeno]

NCSTAR 1-6 page 300 to 304 shows the additional loads put on the east and west walls after impact were about 7% more than their original load and 30 to 35% more on top of that after the alleged south wall failure.

These columns had a 5.00 to 1 factor of safety against gravity. So they were originally only loaded to 20% of their capacity. The NIST after impact and after south wall failure loads would then be

20% x 1.07 x 1.35 = 29%. So even after impact of the north face and alleged south wall failure the NIST report shows they still had a factor of safety above 3.00 to 1.

But... Tony...

I am not an engineer, yet even I can see how the average load on a wall is not necessarily the same as the load on an individual column, and that the stress on the east and west walls after the south wall buckled was largely asymmetrical. I know that wishful thinking is powerful, but one would assume that given your profession you would be above that and not make such an obvious mistake.

 

[BasqueArch]

NCSTAR 1-6 page 300 to 304 shows the additional loads put on the east and west walls after impact were about 7% more than their original load and 30 to 35% more on top of that after the alleged south wall failure.

These columns had a 5.00 to 1 factor of safety against gravity. So they were originally only loaded to 20% of their capacity. The NIST after impact and after south wall failure loads would then be

20% x 1.07 x 1.35 = 29%. So even after impact of the north face and alleged south wall failure the NIST report shows they still had a factor of safety above 3.00 to 1.

The NIST report does not make a case for failure of the east and west perimeter walls. Unfortunately, this just sails right over the heads of most.

Still very wrong.

Factor of Safety= Material Strength/ Design Load
If the columns had an FOS of 5.00 to 1 STATIC load, Bazant proved for the North Tower the DYNAMIC kinetic energy force on one column due to impact from the column above from a drop of the first 12 feet = ~ 31 times the design load.
http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/405.pdf

Example. For say, single column design load of 1 kip x 31 = ~ 31 kip design overload > 5 kip FOS .

It doesn’t surprise me that you re-claim a falling column load onto another column 12 feet below is a static load.
Why are you not embarrassed by this blunder.

 

[Tony Szamboti]

But... Tony...

I am not an engineer, yet even I can see how the average load on a wall is not necessarily the same as the load on an individual column, and that the stress on the east and west walls after the south wall buckled was largely asymmetrical. I know that wishful thinking is powerful, but one would assume that given your profession you would be above that and not make such an obvious mistake.

With the answer you are giving here you shouldn't be patting yourself on the back, because you are wrong.

The additional loading is not an average, it is the maximum on any of the columns.

 

[Tony Szamboti]

Still very wrong.

Factor of Safety= Material Strength/ Design Load
If the columns had an FOS of 5.00 to 1 STATIC load, Bazant proved for the North Tower the DYNAMIC kinetic energy force on one column due to impact from the column above from a drop of the first 12 feet = ~ 31 times the design load.
http://www.civil.northwestern.edu/people/bazant/PDFs/Papers/405.pdf

Example. For say, single column design load of 1 kip x 31 = ~ 31 kip design overload > 5 kip FOS .

It doesn’t surprise me that you re-claim a falling column load onto another column 12 feet below is a static load.
Why are you not embarrassed by this blunder.

The perimeter columns did have a factor of safety against gravity of 5.00 to 1.

You apparently are not paying attention, as what I claimed was still a static load was the load redistributed onto the east and west perimeter walls after the aircraft impact and alleged south wall failure. Pgimeno was talking about dynamic loads before the fall and I corrected him/her.

My point is that NIST does not show the loading required to cause failure of the east and west walls which would then allow the upper section to fall. NIST stops at the alleged south wall failure and Bazant picks up after the upper section is falling. What needed to happen in between was for the core and east and west perimeter walls to fail to allow the drop.

Bazant's analysis also has problems with his stiffness value for the columns and his upper section mass, besides the fact that there could not have been any dynamic load without a deceleration. No deceleration is observed in the fall of the North Tower. The South Tower isn't really measureable that way.