Video Nullfies Pancake/CD Theory

Originally posted by Another_Nut
So the concrete floor slabs for 220 stories is negligible?

I am talking about the part that ejected out, so only a portion of the floor slabs. And it is not to be neglected, but also not that relevant for the collapse to progress.

Than that is why noone takes the os side seriously.

Silly statements like that.

Not sure who "noone" is in your view, but I can not take that statement seriously.

Originally posted by -PLB-
This is in strong conflict with what you said earlier "My floor slabs are designed for little load except for some office furniture".

Now you are saying your floors can hold the mass of a Boeing and the load of several floors.

What I'm actually saying is that each floor would decelerate any mass that falls from above, and in most realistic cases - the top crumbling down, a Boeing parked in the office - so much the collapse would stop after crushing at most six or seven floor slabs, and that you would have to go to great lengths to concentrate a load so heavy that it squeezes its way to the ground floor.

You said so yourself when you quoted Bazant. Wp = potential energy; Wg = "containing" energy; IF Wg > Wp THEN GOSUB(progressive.collapse) ELSE GOSUB(collapse.arrest).

Now you are mixing up a lot of things. You are looking at total potential energy vs total resistance. These are not the conditions given by Bazant, and for good reason, as it is incorrect.

Please elaborate. What's so wrong about comparing total potential energy with total resistance; what's the difference between this and Bazants equations that do the very same thing, just by iterating through each floor? There is none! Instead, it affords a step back to look objectively and reasonably at what Bazant et al are really doing here - in total! I'm not mixing up, I'm adding up and cleaning up the jungle of variables and integrals and getting to the point of what Bazant, Zhou and Verdure are saying actually.

No matter how you look at it, according to them and video evidence, it all boils down to 981 GJ (depending on the true weight of the towers and their true center of mass, probably a little less) being "contained" by only 55 GJ (in the "most optimistic scenario") of tensile (or "internal") energy. Energetically, they're balancing a dull pencil on its tip.

I can only try to put this in laymen's terms as good as I can, I can only try to translate into the languages of physics and engineers even if I'm not fluent in those, and I'm not doing this to troll or something - this is too serious a topic - but because I believe that all it needs is that "aaah" moment I had a few years ago.

And of course the total potential difference of the top floors to ground level is 168 GJ, and if there would not be another 442,000,000 kg of steel and concrete in between, that would surely make for a hell of an impact on ground level - wait, it made for a hell of an impact anyways...

But that was never the question we were asking, we were asking for the kinetic energy upon impact on the topmost floor under the one that we made magically disappear to compare it to the kinetic energy of the plane impact; and all I was trying to say is that the planes brought more energy into the system than a one-story freefall of a 58,000 ton "Block A" would add. It's not even the most important point really, just meant as a little twist of perspective to bring things into relation, yo know - the planes came from the side and hardly made the towers sway, the top comes falling down and takes the whole building with it.

I really enjoy this discussion, especially since I'm the one who talked you into building the world's first working small-scale model of a total progressive gravitational collapse. I feel a little proud of that, to be honest. It would be a shame if we'd now use math to gain the upper hand instead for illumination on our way down the rabbit hole :-)

Originally posted by Akareyon
What I'm actually saying is that each floor would decelerate any mass that falls from above, and in most realistic cases - the top crumbling down, a Boeing parked in the office - so much the collapse would stop after crushing at most six or seven floor slabs, and that you would have to go to great lengths to concentrate a load so heavy that it squeezes its way to the ground floor.

So after 6 floors, what is holding that mass exactly? its not a floor, as that would fail, as its only designed to hold an office, not 6 floors + Boeing. It is also not a column, they are orientated vertically so have no grip on the debris.

So what is holding that mass after 6 floors?

Please elaborate. What's so wrong about comparing total potential energy with total resistance; what's the difference between this and Bazants equations that do the very same thing, just by iterating through each floor? There is none!

When you iterate, you start with an initial mass. This can be chosen arbitrarily. If you choose a mass of 1 floor, then the collapse would arrest according to Bazant's model, as Wg < Wp.

So in case of the WTC, the collapse would arrest in this scenario. In your calculation, there is no such distinction between scenarios.

Instead, it affords a step back to look objectively and reasonably at what Bazant et al are really doing here - in total! I'm not mixing up, I'm adding up and cleaning up the jungle of variables and integrals and getting to the point of what Bazant, Zhou and Verdure are saying actually.

See explanation above.

No matter how you look at it, according to them and video evidence, it all boils down to 981 GJ (depending on the true weight of the towers and their true center of mass, probably a little less) being "contained" by only 55 GJ (in the "most optimistic scenario") of tensile (or "internal") energy. Energetically, they're balancing a dull pencil on its tip.

I can only try to put this in laymen's terms as good as I can, I can only try to translate into the languages of physics and engineers even if I'm not fluent in those, and I'm not doing this to troll or something - this is too serious a topic - but because I believe that all it needs is that "aaah" moment I had a few years ago.

The way I see it is that you missed some ways to look at it. Look at it the way I described above.

And of course the total potential difference of the top floors to ground level is 168 GJ, and if there would not be another 442,000,000 kg of steel and concrete in between, that would surely make for a hell of an impact on ground level - wait, it made for a hell of an impact anyways...

But that was never the question we were asking, we were asking for the kinetic energy upon impact on the topmost floor under the one that we made magically disappear to compare it to the kinetic energy of the plane impact; and all I was trying to say is that the planes brought more energy into the system than a one-story freefall of a 58,000 ton "Block A" would add. It's not even the most important point really, just meant as a little twist of perspective to bring things into relation, yo know - the planes came from the side and hardly made the towers sway, the top comes falling down and takes the whole building with it.

The question we were asking was which has more energy: the top section falling or the plane crash and fires. Though I am not too sure about the amounts, I think we both agree that it was not the figures you came up with, and that the energy from the top section falling may very well be much larger than the planes+fires.

And I think we also agree that the amount of energy released there is much more than that of explosives. Which was my point to start with.

I really enjoy this discussion, especially since I'm the one who talked you into building the world's first working small-scale model of a total progressive gravitational collapse. I feel a little proud of that, to be honest. It would be a shame if we'd now use math to gain the upper hand instead for illumination on our way down the rabbit hole :-)

I am always in for discussion, as long as my opponent is not attempting character assassination. I think you held up pretty good there .

Originally posted by -PLB-
So after 6 floors, what is holding that mass exactly? its not a floor, as that would fail, as its only designed to hold an office, not 6 floors + Boeing. It is also not a column, they are orientated vertically so have no grip on the debris.

So what is holding that mass after 6 floors?

That is not strictly true. Components have to hold their own weight, plus the estimated stress over it's lifetime. It's called factor of safety (FoS)

Generally the FoS for steel in a steel framed building is 4-6. In other words 4 to 6 times over the load the component needed to hold. Over engineering, redundant design, whatever you want to call it, it would not collapse from it's own weight.

Structural steelwork in buildings (FoS) 4 - 6

www.engineeringtoolbox.com...

The factor of safety also known as Safety Factor, is used to provide a design margin over the theoretical design capacity to allow for uncertainty in the design process. The uncertainty could be any one of a number of the components of the design process including calculations, material strengths, duty, manufacture quality. The value of the safety factor is related to the lack of confidence in the design process. The simplest interpretation of the Factor of Safety is

FoS = Strength of Component / Load on component

If a component needs to withstand a load of 100 Newtons and a FoS of 4 is selected then it is designed with strength to support 400 Newtons...

roymech.co.uk...

The reason the collapse would not continue though is not just because of the weight. It is because every floor failing would take energy. Kinetic energy would be lost due to deformation, heat, breaking connections etc.
There was nothing that would increase that energy enough to overcome the resistance.

Newtons 3rd law for every action there is an equal and opposite reaction. The force required to break connections is lost in the object breaking those connections. It doesn't increase like you want to think it does, only in structures that are not connected together, like you little experiment with jenga blocks, that did not take into account resistance, because it had none. Take away resistance it collapses, just like a controlled demolition, not a gravity collapse from fire.

So even IF NIST was correct about the collapse initiation, sagging trusses, they did not explain the collapses themselves, and your hypothesis for collapse completion is simply physically impossible.

Resistance from the structure is what you keep missing in your analysis.

reply to post by Another_Nut


Ok, for starters, have you bothered to do some research into the compressed floors found at the base of the Towers?

Clean up workers at Ground Zero reported finding multiples floors compressed together into a size a fraction of the original size difference. Also found: the floor trusses, floor pans, concrete, floor debris, all squished into a tiny stack.

Originally posted by GenRadek
reply to post by Another_Nut

 

Ok, for starters, have you bothered to do some research into the compressed floors found at the base of the Towers?

Clean up workers at Ground Zero reported finding multiples floors compressed together into a size a fraction of the original size difference. Also found: the floor trusses, floor pans, concrete, floor debris, all squished into a tiny stack.

Yea they also reported finding my friends fathers body. Until a few years later when they admittedit wasn't him when DNA came back as his.

Huh

And please show me how 110 stories of building turns into a pile no biggger than the okc bombing?

There was no pancaking because as you can see in the videos of the towers falling that the concrete floor slabs are being turned to dust.

Or was all that dust covering ground zero just fireproofing that fell off?

O let me guess. Its all in the basement.

So the towers fell . They didn't arrest after a few floors . They fell to the ground.

Then past the ground. And into the basement. Well why did that arrest the collapse? It was only 7 floors to the bottom of the tub. And according to oser there was nothing stopping that building once it got going. Yet the tub wasn't damaged.

So after freefalling all that way it stops right before REAL damage would occurs. The real damage would have been if the tub had been damaged. The cost of fixing the tub. (the major factor in rebuilding)

for me the tub is a forgotten piece of the puzzle.

Eta
if the floors were pancaking down how did the 0/11 surfer survive?

According to your pancake theory he would have been squashed under 90 stories of debris and rubble.

Instead he rode a wave of dust to the ground (200 feet pr so)

Explain how that happens in a pancake collapse please

Originally posted by -PLB-
So what is holding that mass after 6 floors?

What is holding the mass of 10 Jenga blocks in my tower, when one floor alone couldn't?

Please elaborate. What's so wrong about comparing total potential energy with total resistance; what's the difference between this and Bazants equations that do the very same thing, just by iterating through each floor? There is none!

When you iterate, you start with an initial mass. This can be chosen arbitrarily. If you choose a mass of 1 floor, then the collapse would arrest according to Bazant's model, as Wg < Wp.

One floor, you say. E=m*g*h=500000000kg/110 * 9.81m/s² * 3.7m*2=329.972.727 J.

0,33 GJ, that's a close shave, in the most optimistic scenario. Drop two floors and boooom the tower's gone!

So in case of the WTC, the collapse would arrest in this scenario. In your calculation, there is no such distinction between scenarios.

That's what I said. The conditions for arrest can never be met because each and every single floor is too weak for the stuff above and is only in an unstable equlibrium. So Fig. 4a, B/V'07 is valid for the whole structure: the weight (mass times acceleration) is well above the maxwell line of the structure.

The question we were asking was which has more energy: the top section falling or the plane crash and fires. Though I am not too sure about the amounts, I think we both agree that it was not the figures you came up with, and that the energy from the top section falling may very well be much larger than the planes+fires.

Ummm... no? Energy is mass times speed squared (E=m*v²), and although the top may be heavier, it never picks up that much speed even when we assume a free fall (v = sqrt(2*g*s) = sqrt(2*9.81m/s² * 3.7m) = 8.5 m/s). The plane is not as heavy, but its velocity affords its greater kinetic energy. I've not made anything up here, I used official figures and well-known physical laws, I promise.

And I think we also agree that the amount of energy released there is much more than that of explosives.

To which I replied with the metapsysical hypothesis that intelligence, knowledge, purpose and meticulous planning clearly are a form of energy, as a domino experiment will easily show. A vérinage releases no explosive energy at all, it just strategically removes the tensile energy. A traditional CD with explosives is no different from that when it cuts all the beams, starting at the bottom, thus smashing the bottom floor into the ground using the weight of the whole rest of the building. Sometimes, by the way, this goes wrong and... collapse is arrested, or the building leans and topples. Spectators usually cheer and laugh then, I heard "schadenfreude" is one of the few German words in the English language :-)

reply to post by Akareyon


Each FLOOR slab approx 600 tons of concrete + steel decking + trusses are held up with the cleats on the inside & core wall if the mass falling on a floor slab creates a DYAMIC load greater than the safety factor allowed for in the design that fails and falls.

The floor design and the cleats that held the upper floors and the lower floors was exactly the same the only floors that were different were service floors.

So before ANOK jumps in with the usual the core was thicker further down the mass impacting it was GREATER further down. Also look at impact positions and how the towers collapsed

People here seem to forget that the South Tower impact hole extended from the 78th to 84th floors so even going mid way that's 29 floors the North Tower impact hole extended from the 92nd to 98th so midway about 15 floors.

So do you seriously think that floors even if they had a 6 times safety factor could withstand the DYNAMIC loads generated.

The walls pealed away as can be seen in the videos and the large sections lying in the debris and some lower sections still standing with no floors.

The South Tower fell first although hit second not strange considering the far GREATER load above the impact point & fires that's another thing people see to ignore.

reply to post by wmd_2008


You still have the problem of resistance which is going to slow the collapse, regardless of the dynamic load, unless it was more then structure could handle, which it wasn't because it is still only the buildings own mass.

Kinetic energy will still be lost for every impacting floor. Unless more energy is added to the collapse energy would be lost. It would take more mass than was in the structure to crush itself to it's foundations.

The point of the columns being more massive at the bottom is in relation to the cores collapse, not the floors. Get your arguments straight, mate. You constantly show you don't even understand the arguments you are rallying against.

You should really look at the collapses because it is quite clear that the lower floors are blowing out ahead of the tops collapse. That alone discredits NIST, and you. You also keep trying to claim to know how the collapses happened when you can't even show any evidence that sagging (deflected due to heat expansion) trusses can pull in columns.

reply to post by ANOK


You have be linked to the truss info more than once I can't help your memory problem

Do you seriously think the South Towers could survive the MASS of the floors above the impact point as for FOS etc I have to deal with that in my day to day job what is it you do again

Originally posted by wmd_2008
reply to post by ANOK

 

You have be linked to the truss info more than once I can't help your memory problem

And your point is? You always act like you have something that hasn't been addressed, do you seriously think that after nine years I have not seen all you have to offer already a bunch of times?

Do you seriously think the South Towers could survive the MASS of the floors above the impact point as for FOS etc I have to deal with that in my day to day job what is it you do again

Well for a start that is not how the towers collapsed. Again you only have to look at the collapses to see the floors were collapsing ahead of the top section, which BTW was under angular momentum. More so in tower 2, which makes it even more spectacular that both towers collapsed in the exact same way.

Again the MASS would be slowed as resistance takes energy to overcome. To break the connections takes energy, the energy that could not be recovered. But it was, so there had to be another energy acting on the towers that has not been addressed.

In the North tower the top floors were almost gone by the time the bottom floors started popping out...

reply to post by ANOK


Read these word and TRY to understand the questions.

DO you or I or ANBODY know exaclty the damage was caused by the IMPACTS .

I will answer for everybody NO!!!

DO you or I or ANBODY know exaclty the damage was caused by the FIRES

I will answer for everybody NO!!!

Could enough mass fall to cause FLOOR repeat FLOOR failures YES!

Both buildings DIDN'T collapse exactly the same as each other or are you blind
The final result was the same yes the impact points were different the collapse started at different location the buildings fell in relation to the impact points, heights and SUSPECTED damage does that not just sink in with you!

These events are a PRODUCT of the design and the CONDITIONS of the day.

Once those planes entered the building there is NO way for either side to be 100% sure what was damaged, YOU could recreate this event a million times over would the conditons inside after impact be EXACLTY the same every time could YOU or anybody guarantee the PART A would hit COMPONENT B every time NO thats a nature of collisions and explosions.

Get it into your head there is NO WAY that you me or ANBODY can account for all the damage / loadings etc that these buildings were put under that day!

Originally posted by wmd_2008
DO you or I or ANBODY know exaclty the damage was caused by the IMPACTS .

Nope.

DO you or I or ANBODY know exaclty the damage was caused by the FIRES

Nope.

Could enough mass fall to cause FLOOR repeat FLOOR failures YES!

Nope.

Even IF it did it would not continue and destroy the whole tower.

Both buildings DIDN'T collapse exactly the same as each other or are you blind

Doh! The result was exactly the same for each tower, complete global symmetrical collapse.

The final result was the same yes the impact points were different the collapse started at different location the buildings fell in relation to the impact points, heights and SUSPECTED damage does that not just sink in with you!

Hmmm so you expect different damage to result in the same collapse?

LOL why are you getting so angry?

Hmmm suspected is a pretty important word, no? Kind of similar to assume? Even the assumed damage is not going to lead to complete collapse, because the damage was all at the top of the building, which leaves more building that was undamage. Even IF the columns were all completely severed (doubtful) and the top section was lifted up and free fell it would still not be enough mass to crush all the floors to the foundations. Does that not just sink in with you!

These events are a PRODUCT of the design and the CONDITIONS of the day.

Really? Says who, you? Why are you so desperate to convince me? You sound like a ranting kid.

Once those planes entered the building there is NO way for either side to be 100% sure what was damaged, YOU could recreate this event a million times over would the conditons inside after impact be EXACLTY the same every time could YOU or anybody guarantee the PART A would hit COMPONENT B every time NO thats a nature of collisions and explosions.

Again even IF the plane completely destroyed the columns at the impact point it would not cause complete collapse. But regardless once again video proves the collapses do not fit what you are claiming. No matter how much you rant and rave the proof is in the collapses themselves. If you know what you're looking at.

Get it into your head there is NO WAY that you me or ANBODY can account for all the damage / loadings etc that these buildings were put under that day!

Get it in my head? What? Well seeing as no one can account for all the damage then you have nothing either, and that doesn't mean NIST, or you, are correct.

Not one of you can come up with a logical complete explanation for the collapses without contradicting yourselves.

Again WMD, what was it about the truss I was supposed to have missed? And don't try to demand what I should think, you only encourage me mate.

reply to post by ANOK


Just as well YOU don't get on a construction site I will try to explain this to you ONE more time.

EACH floor could ONLY support itself + FOS if a floor failed the only way was DOWN do you think any floor could support the LOAD induced by the mass above it falling

The words underlined seem to be a complete mystery to you.

Once the floors fell that REDUCED the stability of the structure.

reply to post by wmd_2008


I beg to differ. Although not every variable can be known in a chaotic process like this, collisions in general are well-understood and a global analysis is expedient with the right questions asked.

PS: chill out, guys. Could you please stop yelling at each other? My ears a bleeding just reading your posts, if you know what I mean.

Originally posted by Akareyon
reply to post by wmd_2008

 

. Although not every variable can be known in a chaotic process like this,

That's the whole point which seems to be lost on you also!!!

reply to post by ANOK


You were given a link to this on one of the threads read and understand what you can!

New Theory on Tower Collapse

Originally posted by wmd_2008

Originally posted by Akareyon
reply to post by wmd_2008

 

. Although not every variable can be known in a chaotic process like this,

That's the whole point which seems to be lost on you also!!!

...and don't even start yelling at me.

The point that I'm trying to convey is that you don't have to know the variables for each and every bolt, truss, beam, column and weldseam. An approximation will suffice for an overall picture of what is going on. And the overall picture is that two towers dissolved from top to bottom. This phenomenon can be generalized and formalized (you know, science. Because it works). From that, conclusions can be drawn. You come to the conclusion it's all as it should be, I come to the conclusion the towers have been tampered with big time. Now one of us must be wrong. I would not be ashamed to admit if it were me who's wrong, but I'm quite confident that in a few decades your grandchildren will ask what the heck you were thinking.

PS:

Originally posted by wmd_2008
reply to post by ANOK

 

New Theory on Tower Collapse

Originally posted by ANOK
Even the assumed damage is not going to lead to complete collapse, because the damage was all at the top of the building, which leaves more building that was undamage. Even IF the columns were all completely severed (doubtful) and the top section was lifted up and free fell it would still not be enough mass to crush all the floors to the foundations.

Originally posted by Akareyon
I'm fine with any explanation for the initiation of the collapse, I'll go along with Bazant and pretend one floor was removed and there was a one story freefall.

That paper discusses the initiation. That's a detail. We all can only speculate on that, we all agree on that. That's why we go along with the most severe scenario and pretend like Bazant that one whole story just disappeared. And still doubt may be announced that towers naturally behave like the Twins did under such circumstances.

Because what's in dispute is the failure mode of the towers. Total, global gravitational progressive implosive collapse explosion compression dustification from top to bottom which leaves not even a "heap of rubble", but a huge debris field. Which, in its last seconds, shows a portion of its core swaying and then descending into the dust cloud like the mast of a sinking sailing ship, leaving behind a last little cloud of dust blown away by the summer breeze.

reply to post by ANOK


I was just watching the short vid which you posted in this reply.
I began to notice what appears to be atleast three different lateral plumbs of dust coming from the top floors of the north tower at the same time. To me this would indicate the simultanious failure of more than one floor at the point of initiation of the collapes.
These plumbs are not just from a single point, which may suggest some single "explosive detonation". They are almost all the way around the visible portion of the structure.
In your explainations, can it be justified that so much of the upper portion of the building would do such at the same time? I had not noticed this before and am at a lose to determine any mechanism of nature which could be the cause.

Originally posted by teamcommander
reply to post by ANOK

 

I was just watching the short vid which you posted in this reply.
I began to notice what appears to be atleast three different lateral plumbs of dust coming from the top floors of the north tower at the same time. To me this would indicate the simultanious failure of more than one floor at the point of initiation of the collapes.
These plumbs are not just from a single point, which may suggest some single "explosive detonation". They are almost all the way around the visible portion of the structure.
In your explainations, can it be justified that so much of the upper portion of the building would do such at the same time? I had not noticed this before and am at a lose to determine any mechanism of nature which could be the cause.

Ok and this is where im gonna freak you out.

That is happening because above the impact zone the building is freefalling.

While below the impact zone the concrete is literally being pulverized slightly faster and ahead of the falling tops

Allowing the tops of the towers to freefall into the core columns and falling all the way to the ground the ground.

That is why the towers appear to fall at the speed of gravity. Because they are. All the resistance is being destroyed at that same speeed.

Like someone took one shot and (and this is just an analogy...atm ) used an incredible amount of "the force" to push down on the buildings below the impact zone. But it only affected certain materials (concrete for one)

Then a second push do destroy the metals (core beams, desks,filing cabinets, black boxes)

If you start to think about it this explains a lot of the strange goings on. If this posts seems a little confusing im on pain meds lol so just ask for clarification and ill do.