Originally posted by SphinxMontreal

The phony truth movement was obviously initiated and to this day controlled by the same perps who were responsible for the attacks.

How can you make that claim? There is no organized 'truth movement'. If there is then I'm not a part of it.

You think these people would go through all this trouble to plan these attacks and not devise a plan beforehand to marginalize those who would eventually figure out that the OS was a load of horse spit?

Of course not, but I'm smart enough to not have to rely on other peoples opinion to make my own. I don't need a 'truth movement' to know physics, and that the WTC buildings could not collapse the way they did the way we were told.

Is it really that difficult to put up some websites with compartmentalized bits of truth supported by so called professionals and experts?

Of course not, but this does not make the OS correct does it?

I'm sure many have even joined these Truth Movement organizations thinking they're above board and legit. There are even some characters on this site who supposedly belong to these Truth Movement organizations and appear to be quite suspicious in their beliefs. Obviously, these patsies are only allowed to go so far with their nonsense and even attempt to impede and deflect those who are legitimately calling for a real investigation with distractions.

Again so what? It's only in your mind that these so called truth organizations are wrong, on some things I'm sure they are. But the big picture tells me that something is wrong with OS, I didn't need any truth organization to tell me that. Maybe some do but as long as it spreads TRUTH it doesn't matter. Blindly supporting the OS is spreading lies imo.

This is why the Truth Movement, which was started shortly after the attacks, has done absolutely nothing in 9 years, except pick their rear ends. In the eyes of an extremely ignorant dumbed down and mentally challenged public, this lack of productivity by the TM alone is enough to marginalize and discredit those who genuinely seek to investigate the events.

Why do you care if they do anything, what is your beef with that? If it's all lies and nothing is going to come of it then why do you constantly post in this forum? No one is forcing you.

There is no organised 'truth movement' so expecting an organised response is ridiculous. We're just people asking questions, and with help from OS supporters keeping the debate open.

The Truth Movement was built to protect the lies.

What lies would that be?

There will always be people who ask questions, we don't need someone to create an organization for that to happen. 'Truth movement' is just a term generated to stereotype people, and dismiss them based on the most ridiculous claims that can be associated with them. It's nothing new.

Originally posted by bsbray11

Originally posted by -PLB-

So you are given the chance to prove Bazant actually wrong, and you tell me to look for it myself. Its a classic truther response. I looked, I didn't find it. So spew it out already.

No, you were asking me about the safety factors.
...
Do you think it should be my job to give you physics lessons when you admit being ignorant of where Bazant neglected them? If I tell you outright where he did it you would just find something about it to ignorantly bicker about with a slew of fallacies no different than any other time.

and

Originally posted by bsbray11
Show me where Bazant even took the safety factors into account.

Bazant did not overlook factor of safety. Figure 3 from "Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions" (Bazant & Verdure):



Perhaps its only fair to leave it to you to figure out how this diagram proves he did not neglect factor of safety. You can quibble with the magnitude, though it is a construction industry standard, but the notion that it was forgotten is false. I'm now somewhat interested in having you tell outright where he did neglect it.

Originally posted by bsbray11
... and just like when he assumes 95% of the total building mass is available to him the entire time...

From "What Did and Did not Cause Collapse of WTC Twin Towers in New York" (Bazant, Le, Greening, Benson), the section entitled Resisting Forces Due to Ejecting Air and Solids, first sentence of last paragraph:

The computation results shown in figures have been run for (kappa-subscript-e) = 0.2; however, a broad range of (kappa-subscript-e) has been considered in computations, as discussed later.

"kappa-subscript-e" is the mass loss ratio. The nominal value chosen was 20%, which means 80% retained. However, as indicated, many ratios were tested. I myself have tested a wide variety of mass shedding schemes in multiple models. It's not that big of a deal to the mechanics.

Originally posted by bsbray11
He was so wrong, that he didn't even show his work, that there would even be anything to falsify.

False. I think you must be stuck on the monograph released immediately after 9/11. His work is supported in great detail in the two papers cited above. To claim otherwise is... breathtaking.

Originally posted by ANOK

Originally posted by IrishWristwatch

How is that showing the FoS of components, and the combination of components?

It's an idealization, of course. Whether or not this approximation is valid is another matter. The claim was made - multiple times - that Bazant ignored factor of safety. He did not.

That shows columns of one story, the columns were not separated by floors, they were continuous from top to bottom...

Again, it is a simplification; now, let's see how good of one it is. The perimeter columns were pinned top and bottom at every story by the spandrels and floor assemblies, likewise the core had horizontal cross connections and was bounded by the floor spans at each level. So, yes, I'd say it is a good approximation (for the mechanics) in that, despite the three story unit column lengths and essentially contiguous assembly path all the way down the structure, the columns indeed have effective length of one story.

Your alternative is to ignore the lateral bracing and pinning, either by hand wave or by virtue of connections being destroyed during the collapse, but that acts to make the same columns weaker, not stronger. Slenderness ratio.

But the fact is, buckling (either perimeter or core) was not observed on a large scale, so the question is moot. The dominant failure mode appears to be connection failure. Much of the perimeter and core simply fell over in great unsupported lengths, immediately obvious in many videos. If the mode had been buckling, it would've required much more energy, and Bazant's scenario of buckling over one-story lengths maximizes that energy dissipation. Seemingly the opposite of what you think should be the case.

...and tapered in size significantly which means the FoS changes considerably...

As I said, it doesn't matter how strong things are "down there" if "up here" the columns are pinned every story and are constrained to buckle (again, if they were to actually buckle) in story lengths or less. All the same, stop and think for a second: FOS does not necessarily change considerably going down. A constant FOS means capacity scales with imposed load, so simply having matching capacity in members does not increase the FOS. Ideally, FOS would the be the same all the way down regardless of the heterogeneity of mass distribution. An FOS of 2 would support twice the static load no matter the magnitude of load, no matter the location in the structure.

What is really important is the Fos of the combined floor truss connections, because that is what the OS claims failed.

Well, I'm not going to get into defending the grander OS. All I wanted to do was point out some false claims regarding Bazant. I don't even care too much for Bazant's work as a description of the collapses, but a spade is a spade. The engineering work in there is excellent. The political statements in an engineering journal? Uncalled for. The applicabilty to the collapses? Eh.

What pressure the connections could withstand before failure is what is needed to be known.

If I understand what you're saying correctly, I agree.

Bazant considered none of that.

Bazant made mention of fracture as the likely dominant mode of failure. He chose to ignore that path because it categorically results in lower energy dissipation than hinge buckling. Since one of his objectives was to provide a bounding case, this acts in support of that objective. It would be more accurate to model a collapse using connection failure as mode, but a hell of a lot harder. If there's no expectation that it increases chance of survival, the work would not act to define the boundary case.