Merged Applicability of Bazant's model to the real world

[Dave Rogers]

The videos show us one or two corner columns seemingly buckling--columns which would have, in reality, had a very difficult time buckling in because of their very placement. I have not seen videos showing a pulling inward of numerous columns, all in a row or sequence. Please point me to such if I have missed it.

Trinity Church video shows it reasonably clearly. However, you're asking for something different to what I said, which was lateral progression of column failure.

You're merely repeating a belief here as if it's some kind of cause.

No, I'm telling you the result of every calculation made of the collapse dynamics that doesn't involve physically unrealistic assumptions. This includes my own.

What you mean to say is, "Bazant shows it's possible mathematically to describe a gravitational collapse from these causes."

No, what I mean to say is that if the collapse is analysed mathematically this is the result that is obtained.

It is simple, basic physics that would indicate that the downward collapse terminates. Gravitational energy would be expended, both upwards and downwards, in crushing each floor. You do not have a realistic model of physics that can support your bizarre notion of indefinite downward collapse through the path of greatest resistance. You are using anti-science.

I'm at a loss to explain how idiotic this paragraph is. Gravitational energy is converted to kinetic energy due to the downward force accelerating the falling block. Kinetic energy is dissipated by crusshing of supports. If the rate of energy convertion exceeds the rate of dissipation, the collapse propagates. I've done the calculations, and so have many other people (this is the bit that involves actual science, by the way) and found that the rate of conversion exceeds the rate of dissipation by a very comfortable margin. Therefore, science predicts that the collapse propagates.

If you disagree, please tell me which law of physics supports this notion of indefinite downward collapse through a path of greatest resistance.

Newton's Law of Universal Gravitation. This, together with Newton's Three Laws of Motion, applied to the specific structure and known material properties of the towers, predicts global collapse.

Dave

 

[Dave Rogers]

This needs to be qualified by adding: "...if one ignores Newton's Third Law."

No, it needs to be qualified by adding "... if one doesn't handwave away Newton's Law of Universal Gravitation".

Dave

 

[BigAl]

The videos show us one or two corner columns seemingly buckling--columns which would have, in reality, had a very difficult time buckling in because of their very placement. I have not seen videos showing a pulling inward of numerous columns, all in a row or sequence. Please point me to such if I have missed it.

Here you go.
http://video.google.com/videoplay?docid=-5405555553528290546#

 

[Dave Rogers]

Many things are possible mathematically that are not in reality. I'm sure the evolution of unicorns could be mapped and "proven" mathematically, but that does not bring unicorns into being.

Congratulations on a monumentally stupid line of argument, and best of luck in the voting for this month's Stundie awards.

Most of you do indeed appear not to understand Newton's Third Law. Either that or you're deliberately ignoring it for reasons unknown.

Or, possibly, you're the one who doesn't understand it, rather than the overwhelming majority of the world's engineers and physicists. Tough call.

Dave

 

[GlennB]

The videos show us one or two corner columns seemingly buckling--columns which would have, in reality, had a very difficult time buckling in because of their very placement. I have not seen videos showing a pulling inward of numerous columns, all in a row or sequence. Please point me to such if I have missed it.

You're welcome. I believe this is from the Trinity Church video mentioned.

 

[Dave Rogers]

Countdown to ergo claiming he can't see the columns buckling inwards in 3... 2... 1...

Dave

 

[ergo]

Each floor can support up to 1 million Kg before the connections fail.

All clear ?

If we put over 1 million Kg on the floor, it's connections fail.

It doesn't matter whether that >1 million Kg is moving or not, or whether it's in one solid piece or pea sized chunks. It still weighs over 1 million Kg, and the floor connections cannot support over 1 million Kg.

Even if this is what happened (that the upper block could "fall" through the 85% remaining columns) you would still have the collapse arresting. Collapse does not progress unidirectionally. Both sections of colliding floors will suffer damage, not just those of the lower blocks. What is it about this you don't understand?

 

[Dave Rogers]

Even if this is what happened (that the upper block could "fall" through the 85% remaining columns) you would still have the collapse arresting. Collapse does not progress unidirectionally. Both sections of colliding floors will suffer damage, not just those of the lower blocks. What is it about this you don't understand?

The bit where the debris from the upper block mysteriously vanishes.

Dave

 

[Newtons Bit]

Even if this is what happened (that the upper block could "fall" through the 85% remaining columns) you would still have the collapse arresting. Collapse does not progress unidirectionally. Both sections of colliding floors will suffer damage, not just those of the lower blocks. What is it about this you don't understand?

And if you watch the videos, it doesn't progress "unidirectionally". Amazing, the real-world works the way it's supposed to!

 

[ergo]

No, I'm telling you the result of every calculation made of the collapse dynamics that doesn't involve physically unrealistic assumptions. This includes my own.

What were your calculations for the force of impact being absorbed by both upper and lower portions of the building?

Gravitational energy is converted to kinetic energy due to the downward force gravity accelerating the falling block. Kinetic energy is dissipated by crusshing of supports.

In both upper and lower blocks.

If the rate of energy convertion exceeds the rate of dissipation, the collapse propagates.

In a nutshell, what you mean to say is, if the kinetic energy from a gravity driven descent exceeds the capacity of the lower block to absorb and transmit it back upward, at each moment of impact, then collapse propagates. In real life, in all buildings where a smaller upper block is attempting to descend through a much larger lower block, the lower block wins. If you disagree, please provide an example outside of the one you're trying to claim. Thanks.

Newton's Law of Universal Gravitation. This, together with Newton's Three Laws of Motion, applied to the specific structure and known material properties of the towers, predicts global collapse.

Please apply Newton's Three Laws of Motion to the WTC 1 and 2 collapses. I've never actually seen a da bunker do this. They usually just mention the laws as if they're using them, without actually explaining how they apply. It's interesting, because it's Newton's First and Third laws that completely arrest your theory in its tracks, so I'd like to see how you explain your way around this. It would be a first.

 

[ergo]

The bit where the debris from the upper block mysteriously vanishes.

The debris from the upper block? So you are admitting that the upper block is crushing itself up before it can crush anything down?

 

[ergo]

And if you watch the videos, it doesn't progress "unidirectionally". Amazing, the real-world works the way it's supposed to!

Thank you for acknowledging this. We see the upper block crushing up well before any crushing down could possibly begin.

 

[carlitos]

re: applicability of Bezant's model to the real world

The lower block is unable to support the dynamic load from the upper block, whether that block is a single intact unit, a composite of an intact unit and an intervening rubble layer, or a disconnected accumulation of rubble.

In real life, in all buildings where a smaller upper block is attempting to descend through a much larger lower block, the lower block wins.

The columns were no longer lined up. They missed each other. The columns pierced through the 4" concrete floors. No "blocks" involved.

 

[ergo]

The columns were no longer lined up. They missed each other. The columns pierced through the 4" concrete floors...

The columns of both upper and lower blocks pierced through the 4" concrete floors/ceilings of both upper and lower blocks. And then what?

 

[femr2]

This is probably futile, but...

Even if this is what happened (that the upper block could "fall" through the 85% remaining columns) you would still have the collapse arresting.

Ask yourself...

Arresting upon WHAT exactly ?

Both sections of colliding floors will suffer damage, not just those of the lower blocks.

Of course.

Again, ask yourself...

What difference does this make, other than the descending mass having now acquired the additional mass of an additional floor ?

What is it about this you don't understand?

What I don't understand is that, even though I've made it as simple for you as possible, you still don't get it.

 

[femr2]

The columns of both upper and lower blocks pierced through the 4" concrete floors/ceilings of both upper and lower blocks. And then what?

And then, even in static conditions, you have an *upper block*, which weighs FAR more than one floor can support, resting on one floor.

It fails.

Repeat.

 

[DGM]

This is probably futile, but...

.

"truthers" can be annoying that way. I have to say it's been fun watching you try to reason with ergo and Tony.

 

[ergo]

And then, even in static conditions, you have an *upper block*, which weighs FAR more than one floor can support, resting on one floor.

It fails.

Repeat.

The "one floor" trope is a misconception propagated among the anti-science crowd. It is not just one floor holding up the upper block, as any structural engineer will tell you. Just as it is not just the one lower floor of the upper block holding the rest of the upper block up. Right? It is the entire construction of both upper and lower blocks that are holding the higher floors above the lower floors. That is what a structural steel framework is and does. Your "one floor" theory is bunk.

 

[carlitos]

Not one floor of the structure. One actual floor slab. The columns are mis-aligned, which is why they are now one floor lower!

 

[ergo]

Not one floor of the structure. One actual floor slab. The columns are mis-aligned, which is why they are now one floor lower!

Wtf does this mean?

So then go back to this question.