Moderated Steel structures cannot globally collapse due to gravity alone

[tfk]

"Fires were in the process of heating new members"


When i read goofy stuff like that, it makes me spit up the energy drink i am having a sip of.

Those fires were not hot, nor longlasting in any location in that building.

How any sane person can possibly believe a column so big that it is 7 tons per floor in mass(and a big guy couldnt even come close to wrapping his arms around its FIREPROOFED girth)it gives me the willies about the "critical thinking" going on around here

It makes me think of an apt comparison. Holding up a cigatette lighter at an indoor concert, and wondering if that small flame will bring the whole arena crashing down...........................

The fires were precisely as hot as office fires are everywhere. I am curious to know why you think a bunch of office contents (i.e., paper & plastics) would burn cooler inside that building than they would in any office building.

Should I assume that you are aware of the temperatures that the beams were brought to in order to cause the failure? Do you REALLY find it hard to believe that the beams were brought to this LOW temperature?

After 7 hours of burning? With no working sprinkler system & no fighting of the fires?

 

[GlennB]

.....But there are 97 storeys below that absorb the energy and then ... the upper part just bounces. No rubble is formed....

Next time someone is planning to drop a brick on my head I'll make sure I'm standing at the top of a human pyramid so that the others can share the damage equally.

 

[Heiwa]

Next time someone is planning to drop a brick on my head I'll make sure I'm standing at the top of a human pyramid so that the others can share the damage equally.

Yes, a little piece of brick dropped on a brick will not crush the brick. Aha, it was your head, you worried about. Drop a piece of your head on your head and report the result. Who is planning that?

Why do you liers always make the object being dropped more solid, rigid (?) than what it is supposed to drop on? Everyone knows that a strong object when hitting a weak object (you?) will hurt the weak object. You are weak?

In the WTC 1 case what's dropped, if it is dropped, is not strong. It is 95% air. It cannot crush anything below it.

 

[Bell]

In the WTC 1 case what's dropped, if it is dropped, is not strong. It is 95% air. It cannot crush anything below it.

Anything below, that is 95% air as wel?

Why don't you stick to something you DO* understand? Ships. You could investigate the Titanic. Ice cutting open a steel ship? Puh-lease...

* Presumably

 

[Christopher7]

The mass of the entire top section of just the north tower alone when falling on the lower section in dynamic load was the rough equivalent of putting 8 g's worth of force on those floors.

The core columns did not snap instantly and simultaneously, they would have buckled which takes a little time. The upper section could not hit the lower section with 8 g's of force unless the columns were removed with explosives.

Bazant's theory requires all the accumulated weight be applied evenly to each successive floor.

Most of the debris, perhaps 80% or more, was ejected outside the building.

 

[Grizzly Bear]

You are simply wrong. What Bazant says (lies) is that the kinetic energy of the upper part exceeds 8X what one storey below can absorb = an 0.9 m layer of rubble is formed = crush down continues (and upper part C remains intact). But there are 97 storeys below that absorb the energy and then ... the upper part just bounces. No rubble is formed.

The size of the "lower section" compared with the "upper section" is entirely irrelevant. What is relevant is if the mass plowing into an individual floor or section of the structure far exceeds it's ability to carry the loads then it will fail. This is not helped when the mass of another floor is added. You are treating the entire structure monolithically which is entirely a mistake.

The core columns did not snap instantly and simultaneously,

You're right, it took 52 minutes for the south tower, and 102 minutes for the north tower before the structural integrity was catastrophically impaired. The exterior columns were reportedly bowing inward long before the collapse of both buildings, and reports from aerial observers have noted that the north tower above the impact point was leaning, seems like a straight forward warning sign that the stability of the building is in question.

they would have buckled which takes a little time.

See above

The upper section could not hit the lower section with 8 g's of force unless the columns were removed with explosives.

Excuse me? Once the collapse gets going, whether it's a controlled demolition or from a catastrophic case of structural failure, it's governed by gravity, and when it hits an object it's dynamic load will far exceed its static load. Steel members aren't infinitely strong, when they fail, they... fail.

Bazant's theory requires all the accumulated weight be applied evenly to each successive floor.

Which ironically is as biased against collapse progression. He intentionally tries to offer the most ideal conditions that would have the best likely hood of collapse arrest, and his figures demonstrated that even in the most optimal scenario biased against collapse, the building still would have.

Most of the debris, perhaps 80% or more, was ejected outside the building.

Where did you arrive at your figures?

 

[Heiwa]

The size of the "lower section" compared with the "upper section" is entirely irrelevant. What is relevant is if the mass plowing into an individual floor or section of the structure far exceeds it's ability to carry the loads then it will fail. This is not helped when the mass of another floor is added. You are treating the entire structure monolithically which is entirely a mistake.

No, I just apply a force to the complete lower structure -part A - and not only its top floor to demonstrate that the complete lower structure is quite flexible. It seems Bazant assumes that only the top floor is flexible and that the rest of the lower section is rigid. Evidently the top floor is then crushed when 'the mass is plowing into it'. This mass plowing into the lower section is the upper section - part C - and it is not rigid either. So when it plows into the lower section, it will also be seriously affected. The lower section applies forces on it so the upper section decelerates.

Of course Bazant and NIST suggest that the upper section/mass part C plowing into the lower section part A is rigid and is not affected by forces acting on it (no deceleration) ... but that is nonsense. Bazant suggest that part C applies a force 8g on part A to crush the top storey of part A and conveniently forgets that part A then should apply a similar force 8g on part C to crush its lowermost storey.

Further nonsense by Bazant and NIST is that when upper section part C plows into lower section part A a new part B is formed - rubble. This is just an invention to hide the simple fact that both parts A and C should just be locally damaged at the contact area ... and that arrest of damages should soon follow.

You wonder what kind of mistakes NIST and Bazant do? Are they just stupid or do they them intentionally? It would appear that neither NIST nor Bazant has done a structural damage analysis ever.

 

[tuc0]

blablabla

I know Prof. Bažant.
Prof. Bažant is a relative of mine.
You, sir, are no Prof. Bažant.

 

[Heiwa]

I know Prof. Bažant.
Prof. Bažant is a relative of mine.

Good! Ask Prof. Bažant why he invents a new theory of two similar structures colliding at WTC 1 on 911 and why and how the smaller, upper one - part C - crushes the bigger, lower one - part A - without getting damaged (until crush up), how part C can produce a part B - rubble - without getting damaged, etc, etc. In my opinion everything Prof. Bažant writes and publishes of this subject is ... fantasy. Or worse. Has Prof. Bažant read my little article at http://heiwaco.tripod.com/nist3.htm ?

When ships collide, e.g. a small ship impacting a big ship, the big ship is never crushed 100% while the small ship remains intact ... and the small ship never disappears in a crush up after having destroyed the big ship.

 

[Lennart Hyland]

When ships collide, e.g. a small ship impacting a big ship, the big ship is never crushed 100% while the small ship remains intact ... and the small ship never disappears in a crush up after having destroyed the big ship.

One example of why comparing ships and buildings is false.

 

[Bell]

When ships collide, e.g. a small ship impacting a big ship, the big ship is never crushed 100% while the small ship remains intact ... and the small ship never disappears in a crush up after having destroyed the big ship.

But what if the ships are carrying lemmons?

 

[GlennB]

Yes, a little piece of brick dropped on a brick will not crush the brick. Aha, it was your head, you worried about. Drop a piece of your head on your head and report the result. Who is planning that?

OK - If someone dropped a small pig's head onto mine, would it help me to stand on a pyramid of people so that they can help share the impact? Would their SE prevent my skull being damaged? Bear in mind that my pyramid is standing on solid ground. It has the entire world underneath . The SE of The World is very large indeed. So how come my skull is in serious danger from a similar but smaller skull falling on it?

Why do you liers always make the object being dropped more solid, rigid (?) than what it is supposed to drop on? Everyone knows that a strong object when hitting a weak object (you?) will hurt the weak object. You are weak?

Can a 'weak' object ever break a 'stronger' object? Can a soft lead bullet penetrate harder steel? Can a tennis ball made of rubber+fabric penetrate harder glass?

 

[Heiwa]

OK -

1. If someone dropped a small pig's head onto mine, would it help me to stand on a pyramid of people so that they can help share the impact? Would their SE prevent my skull being damaged? Bear in mind that my pyramid is standing on solid ground. It has the entire world underneath . The SE of The World is very large indeed. So how come my skull is in serious danger from a similar but smaller skull falling on it?

2. Can a 'weak' object ever break a 'stronger' object? Can a soft lead bullet penetrate harder steel? Can a tennis ball made of rubber+fabric penetrate harder glass?

1. Why would anyone drop a pig's head on you? Carry a safety helmet! It diverts impacts.

2. When object C impacts object A, C applies a force F on A, and A a force -F on C. There is equilibrium. F - F = 0. But forces F and -F are real and affect A and C. A and C may deform, get damaged, fail, etc, etc. Use clear thinking and find out yourself. Don't suggest that little C remains intact, creates at layer part B that is a crushed bit of A and then destroys big part A completely. It doesn't work like that. Even if Bazant and NIST suggest it. They are simple fools.

No, as my professors H and S of structural analysis at C university at G always told me - always check where the forces F and -F are and what they are up to.

Remember that if C is at 100% free fall it cannot apply any force F on A. F = 0. And when F = 0 nothing happens.

 

[funk de fino]

1. Why would anyone drop a pig's head on you? Carry a safety helmet! It diverts impacts.

Nice dodge liar.

 

[Seymour Butz]

In reality the columns will slice the floors, etc.

Correct!

So what happens when the columns are no longer braced?

Will they buckle and/or break at the welds?

And if they do, do you agree that the collapse will continue?

 

[Ratas]

Kudos for Heiwa, you make me study harder, don't want to end up with knowledge as deep as yours. I surely hope that you went deeper into this whole mechanics thing than just F and -F. You constantly ignoring all requests for structural calculations indicate otherwise. It wouldn't be too difficult to do a simplified calculation of e.g one level of floor slabs falling down to the lower ones. No more idiotic analogies or dodging bullets, please provide something. And I know I am doing the forbidden feeding, but the combination of tomorrows exam and this nonsense of Heiwa is just too much at the moment.

 

[DGM]

Kudos for Heiwa, you make me study harder, don't want to end up with knowledge as deep as yours. I surely hope that you went deeper into this whole mechanics thing than just F and -F. You constantly ignoring all requests for structural calculations indicate otherwise. It wouldn't be too difficult to do a simplified calculation of e.g one level of floor slabs falling down to the lower ones. No more idiotic analogies or dodging bullets, please provide something. And I know I am doing the forbidden feeding, but the combination of tomorrows exam and this nonsense of Heiwa is just too much at the moment.

Good luck on your exam.

If it's any consolation to you, he doesn't really believe what he spews. It's all for the attention that we (and that's it) give him.

BTW welcome to the nut house.

 

[Heiwa]

Correct!

1. So what happens when the columns are no longer braced?

2. Will they buckle and/or break at the welds?

3. And if they do, do you agree that the collapse will continue?

1. Only two outer walls of upper and lower parts A and C slice floors on the inside. Similar happens at the core. The part A columns then do not carry any load and are still braced by the spandrels. Think 3-D!

2. They will thus remain undamaged.

3. Only local failures of some floors take place, the floors hinge and get entangled. The failures are not symmetrical. Upper part C gets jammed. The drop is arrested. Serious fault of NIST, Bazant & Co is to model the crush down in 1-D. There are no floors to be sliced in 1-D. Floors do not exist for them.

All explained in my paper.

 

[DGM]

Ratas:
See what I'm saying?

 

[Heiwa]

Kudos for Heiwa, you make me study harder, don't want to end up with knowledge as deep as yours. I surely hope that you went deeper into this whole mechanics thing than just F and -F. You constantly ignoring all requests for structural calculations indicate otherwise. It wouldn't be too difficult to do a simplified calculation of e.g one level of floor slabs falling down to the lower ones. No more idiotic analogies or dodging bullets, please provide something. And I know I am doing the forbidden feeding, but the combination of tomorrows exam and this nonsense of Heiwa is just too much at the moment.

All calculations are in my papers! Re calculations; NIST could not even calculate PE or SE to show PE>SE. I do it and find PE < 1000 SE! And the Bazant & Co calculations are just 1-D - density of towers and rubble (sic) in kg/m, etc. Very funny density. Yes, I am 1.90 m tall and weigh 80 kgs. So my density is 42.10 kg/m! Ever heard any serious scientist using such units for density?