Moderated Steel structures cannot globally collapse due to gravity alone

[BenBurch]

Heiwa, what do you think happens to that building if you push the wall elements out 3 feet on two sides? What holds up the floors then?

Well?

 

[beachnut]

... These guys are gaga!

Your paper is gaga as you continue to post the most anti-intellectual tripe on the WTC you can. Your lemon WTC analogy is gaga and is indicative of your delusional ideas on 911. Lemon – that is your paper.

 

[phunk]

Overall structural stability, whatever that can be, is not affected by local failures, e.g. 287 columns simultaneously kneeling in the initiation zone - not seen of course

Of course all 287 are not seen. The witnesses to what went on inside the building as it collapsed obviously can't testify.

But the ones we can see, all of the exterior columns, clearly do buckle at the start of the collapse.

 

[A W Smith]

What I learned from Gravy's Heiwa page

Well at least I learned what Frankenstein would look like if he wore aviators



Heiwa, What if you were to drop a child down a well? Would it crush the flower petals that the child had already dropped into that well?

 

[Furcifer]

I am leaving for ski vaccation, anyway. See you in March at some other thread.

New Thread: "Skier dies in avalanche, despite warnings of instable conditions"
last heard saying "I am more rigid than snow, snow falls at at a rate less than the speed due to gravity, how can a less dense material such as snow crush a more rigid, dense body such as myself?"

Have a good trip Heiwa, stay on the groomed trails please.

 

[bill smith]

Of course all 287 are not seen. The witnesses to what went on inside the building as it collapsed obviously can't testify.

But the ones we can see, all of the exterior columns, clearly do buckle at the start of the collapse.

]

Do you tink the perimeter columns were bending inwards like that all around the building ?

(Sorry I had to remove the picture. Apparently I can't post links until I've made at leat 15 posts)

 

[Gravy]

Do you tink the perimeter columns were bending inwards like that all around the building ?

No, the inward bowing of the east wall of the south tower was visible beginning about 18 minutes after flight 175 struck, and worsened until the entire wall buckled inward. The failures progressed around the tower in a couple of seconds, but the other walls weren't visibly bowed inward, except, of course, where the plane entered (south wall).

 

[Christopher7]

Most of the debris fell outside the footprint.

A graph of debris distribution by weight against distance would be nice. Even a vague estimate would help. If you don't have that, then you're making things up.

Brent Blanchard estimated 95%. I think that's a bit high. Others have estimated 80% so it's safe to say 'most'. It would be impossible to give an accurate estimate as you well know.

Your off-the-cuff math does not give a reasonable estimate of how much energy it would take.

Please feel free to substitute a reasonable estimate of your own.

First you have to estimate how much debris and how far on average. Bazant estimated 20%. That's way low.

Extra credit will be given for demonstrating how much energy would be required to move the upper section laterally by 208 feet, which you insist would have happened had the lower block not been destroyed by explosives, and showing that this is less than the energy required to eject 4-ton sections up to 600 feet.

Your sophistry is showing. The top section did not move laterally 208 feet, it was tilting, but you know that. As gravity pulled on side down, the top part of the top section was set in motion to the side as well as down. Once in motion to the side it would stay in motion to the side and the added weight on the tilt side would increase this motion by collapsing the tilt side faster than the 'high' side.

 

[Dave Rogers]

Brent Blanchard estimated 95%. I think that's a bit high. Others have estimated 80% so it's safe to say 'most'. It would be impossible to give an accurate estimate as you well know.

Good, so now you've got some estimates of how much debris finished up outside the footprint. Next, how much of that was expelled at what stage of the collapse?

Your sophistry is showing. The top section did not move laterally 208 feet, it was tilting, but you know that. As gravity pulled on side down, the top part of the top section was set in motion to the side as well as down. Once in motion to the side it would stay in motion to the side and the added weight on the tilt side would increase this motion by collapsing the tilt side faster than the 'high' side.

Your inconsistency is showing. The first two bolded parts show where a lateral component of velocity was required for the top part to fall off. Where is the energy coming from to supply this lateral velocity, and why is it obvious that this energy can be supplied by the dynamics of the collapse, but the much smaller amount required to eject column trees can't? You've even shown that you understand the mechanism by which objects can fall to the side, despite your earlier scientifically illiterate insistence that there is no mechanism by which vertical kinetic energy can be converted to horizontal kinetic energy.

Your refusal to see what you don't want to see is also showing. Slice it any way you want, the upper section cannot fall off the lower without its centre of gravity moving at least 208 feet sideways. This is not sophistry but geometry. You're trying to argue that it moved without moving because of the details of how it moved.

You've also continually refused even to try and work out how fast the upper block was moving. As you yourself said, unless you plug in some numbers, the equations are meaningless. Plug in some numbers.

Dave

 

[Christopher7]

Good, so now you've got some estimates of how much debris finished up outside the footprint. Next, how much of that was expelled at what stage of the collapse?

Debris was being ejected throughout the collapse. You are asking me for calculations that Bazant should have done.

The first two bolded parts show where a lateral component of velocity was required for the top part to fall off. Where is the energy coming from to supply this lateral velocity,

Bazant does not calculate how much energy would be diverted from the downward acceleration to accomplish the horizontal acceleration.

why is it obvious that this energy can be supplied by the dynamics of the collapse, but the much smaller amount required to eject column trees can't?

Who says it's a smaller amount? We're not talking about one column tree.

Who said it couldn't be supplied? The question is, how much energy. Bazant's calculations are flawed because he used 20% as the amount of debris ejected which is way low.

the upper section cannot fall off the lower without its centre of gravity moving at least 208 feet sideways.

Wrong. The top section would fall off when the center of gravity moved 105 feet sideways.

This is not sophistry but geometry. You're trying to argue that it moved without moving because of the details of how it moved.

That is a rediculous claim, more sophistry.

You've also continually refused even to try and work out how fast the upper block was moving. As you yourself said, unless you plug in some numbers, the equations are meaningless. Plug in some numbers.

How fast? Again you are asking me to do the calculations that Bazant should have done.

 

[Dave Rogers]

Wrong. The top section would fall off when the center of gravity moved 105 feet sideways.

For the top section to fall off, it would have to move far enough sideways that none of it intersected the structure below. That's 208 feet. Moving it 105 feet sideways might make it inevitable that it would eventually fall off, but it would have to move another 103 feet to actually do so. The energy to move it that distance has to come from somewhere.

Again you are asking me to do the calculations that Bazant should have done.

Any calculations at all from you would be nice. You seem to think they're not relevant, and that you can simply state your conclusions as axiomatic. Unfortunately, your axioms are generally absurd.

Dave

 

[GlennB]

Debris was being ejected throughout the collapse. You are asking me for calculations that Bazant should have done.

...

Who said it couldn't be supplied? The question is, how much energy. Bazant's calculations are flawed because he used 20% as the amount of debris ejected which is way low.

Yesterday I was watching "Brainiac" (a wacky UK tv <cough> 'science' program). They were simulating earthquakes and measuring the outcome with a seismometer. One experiment involved dropping two large pallets of bricks close to the instrument. There was a great deal of horizontal ejection of bricks. But only when they hit the ground.

Bear in mind, Chris7, that when it had nowhere else to go - it had hit the ground - the WTC debris would inevitably tend to spread sideways. If your "20% ... way low" comment doesn't consider this you might need to think again about your estimate.

 

[Christopher7]

For the top section to fall off, it would have to move far enough sideways that none of it intersected the structure below. That's 208 feet. Moving it 105 feet sideways might make it inevitable that it would eventually fall off,

That's what I meant.

but it would have to move another 103 feet to actually do so. The energy to move it that distance has to come from somewhere.

True, the energy is gravity. Bazant did not allow for this energy redirection in his calculations nor did he subtract the weight that was removed from the high side.

You intentionally misinterpret what I say and criticize me in an attempt to shift the focus away from the fact that:

Bazant did not allow for the energy necessary to move the top section sideways or the weight loss as it moved off center. He has a theory about an event that did not occur rather than the one that did.

 

[Christopher7]

Yesterday I was watching "Brainiac" (a wacky UK tv <cough> 'science' program). They were simulating earthquakes and measuring the outcome with a seismometer. One experiment involved dropping two large pallets of bricks close to the instrument. There was a great deal of horizontal ejection of bricks. But only when they hit the ground.

Bear in mind, Chris7, that when it had nowhere else to go - it had hit the ground - the WTC debris would inevitably tend to spread sideways. If your "20% ... way low" comment doesn't consider this you might need to think again about your estimate.

Good point.
The videos show a great deal of dust, debris and frame sections being ejected in all directions all the way down. All the exterior framework fell outside the perimeter. There were many 4 ton framing sections thrown up to 600 feet. Bazant's collapse requires that 80% of the total remain within the perimeter until the crush-up stage begins. He only speaks of light debris being ejected up to 600 feet.

"Kout~ 0.2 (20%) Based on the known typical density of rubble"
"In calculations, the large fluctuations are neglected. We introduce here a generalization in which we add energy consumed by the breakup of concrete floor slabs, energy to expel air from the tower, and energy required to accelerate the mass of dust and larger fragments ejected from the tower."

"The high velocity of air jetting out also explains why a large amount of pulverized concrete, drywall and glass was ejected to a distance of several hundred meters from the tower." [nothing about 4 ton framework sections]

 

[funk de fino]

C7

In the first 1.5 secs of the collapse how much was thrown 600 feet?

How much did the top section shed in that timeframe?

 

[beachnut]

That's what I meant.

True, the energy is gravity. Bazant did not allow for this energy redirection in his calculations nor did he subtract the weight that was removed from the high side.

You intentionally misinterpret what I say and criticize me in an attempt to shift the focus away from the fact that:

Bazant did not allow for the energy necessary to move the top section sideways or the weight loss as it moved off center. He has a theory about an event that did not occur rather than the one that did.

It is a model; you will need to go to engineering school to understand this. Why have you wasted 7 years to fail to do what the Passengers on Flight 93 did in minutes; figure out 911.

You missed the boat, train, and the plane on this one. Gee, Watergate garnered a Pulitzer Prize; 911Truth has garnered delusions.

You must gain some knowledge and stop attacking models when you need to do your own work, your own model to prove the WTC can’t collapse.

Bigger problem, Robertson, the chief structural engineer for the WTC Towers, says the collapse is how it would happen with impacts 7 to 11 times greater than his design impact and fires not fought. So you need to come up with a rebuttal based on structural engineering not hearsay, lies and fantasy you and 911Truth make up out of the blue due to yours and 911Truth’s failed opinions.

 

[Christopher7]

In the first 1.5 secs of the collapse how much was thrown 600 feet?
How much did the top section shed in that timeframe?

Your questions are rhetorical and ignore the point.
It is not known when the 4 ton frame sections were ejected.
Bazant does not explain how they were ejected up to 600 feet, only that they were ejected at velocity z˙

 

[Christopher7]

It is a model

Correct.

However, it is NOT a model of what actually happened to the south tower.

It assumes that only 20% of the mass was ejected outside the perimeter.

It does NOT explain how numerous 4 ton frame sections were ejected up to 600 feet.

 

[Furcifer]

Bazant does not explain how they were ejected up to 600 feet, only that they were ejected at velocity z˙

Could you summarize why you think this is important, and what your explaination is?

 

[bill smith]

Your questions are rhetorical and ignore the point.
It is not known when the 4 ton frame sections were ejected.
Bazant does not explain how they were ejected up to 600 feet, only that they were ejected at velocity z˙

Chris- how definate is the inforation that 4-ton chunks were thrown 600 feet ?