What is Crushing This Tower?

Originally posted by -PLB-

It is just unbelievable how rubbish your understanding of physics is. How can a lower floor have any influence on the load capacity of a higher floor? What matters is the force on the connections. Explain why according to you the force on the lower connections is smaller than the force on the upper connections. (In reality, it is the exact opposite by the way).

edit on 18-7-2011 by -PLB- because: (no reason given)

Is it both floors, and connection. Both will cause resistance to the collapse, as I explained already. There was not enough mass in the top to break the connections, the holding force of the connections would be more than than the force of the dropping top.

IF the connections all break, you still have floors stacking up, unless of course they were ejected during the collapse... Then you have no mass to crush floors.

Of course we know the top did not do what you claim...



How did the 47 core columns telescope down through an increasing mass PLB, Mr. Electrical Engineer who couldn't answer basic physics questions, remember that, need a reminder?

reply to post by wmd_2008


You say all that and then think this link is correct?

www.nmsr.org...

The site is so full of assumptions, and nonsense, that has been debunked already.

If you think sagging trusses can snap, or even put a pulling force on the large columns they were attached to, then you don't know as much as you assume you do.

Even NIST dismissed the pancake/progressive collapse hypothesis, so why do you insist on arguing for it?

Originally posted by ANOK
reply to post by wmd_2008

 

Even NIST dismissed the pancake/progressive collapse hypothesis, so why do you insist on arguing for it?

A lack of any form of pancaking removes their *compressed air squibs* theory

Originally posted by Seventh

Originally posted by ANOK
reply to post by wmd_2008

 

Even NIST dismissed the pancake/progressive collapse hypothesis, so why do you insist on arguing for it?

A lack of any form of pancaking removes their *compressed air squibs* theory

You don't hear much about squibs any more. Are they the thermite exploding?

Originally posted by TrickoftheShade

Originally posted by Seventh

Originally posted by ANOK
reply to post by wmd_2008

 

Even NIST dismissed the pancake/progressive collapse hypothesis, so why do you insist on arguing for it?

A lack of any form of pancaking removes their *compressed air squibs* theory

You don't hear much about squibs any more. Are they the thermite exploding?

There were explosions?...source.

reply to post by Seventh


You mean these pancaked floors at the South Tower I take it!!!





Decking, truss steel and reinforcement visible

Even if the concrete of the 110 floors was laid gently one on top of the other with NO DAMAGE it would be ONLY 41.25 feet high avg floor thickness of concrete was 4.5".

Originally posted by ANOK

Even NIST dismissed the pancake/progressive collapse hypothesis, so why do you insist on arguing for it?

ANOK, NO they did not. They dismissed pancaking as the INITIATOR of the collapse. The floors DID pancake once collapse initiated. It was initiated via trusses pulling in on the exterior columns and the exterior columns snapping after bending inward. THAT is what NIST stated. The floors ended up pancaking, and even NIST states the floors PANCAKED afterward.

How many times do you need to be corrected before it sinks in? Or do you just enjoy lying?

reply to post by JBA2848

I think your theory is wrong for a few reasons, mainly because of a documentary i watched. They had actual phone conversations of people trapped in the tower calling their loved ones. One gentlemen in specific had th unfortunate chance of being on the phone when the collapse happened. I would have to wonder how this guy was still standing around talking on a cell phone if the building was internaly collapsing? I would have to believe he would of noticed that. I also believe we would of been able to hear or discover by some other method that the building was internally collapsing. I think that would make some serious noise and vibrations.

There are more reasons I know your theory is which I don't really need to go into detail as the above evidence alone ruins your theory. As far as I'm concerned, every debunker on here is wasting their time until they can explain building 7. If you can't explain building 7, then you do not have th technical know how to explain wtc1/2 sufficiently.

I can't believe there are still people on these forums that argue for the os. I can't even remember the last time I talked to someone in person who believed the os. Must be getting lonely!

reply to post by wmd_2008

You mean these pancaked floors at the South Tower I take it!!!

Haven't we addressed this already?

Where is your evidence that this picture is of the south tower rubble? It could be from anywhere and that site (FDNYPhoto.com doesn't say).

I have shown you the street layout suggests that this cannot be from the south tower, to the left of that picture is the slurry wall which was not immediately adjacent to either of the towers.





This next image (from here) shows that what you are looking at is almost certainly basement parking structures. Calling this "the south tower" is misleading at best, grossly distorting reality at worst. This had nothing to do with the main sequence collapse.



This is a repetition of adding the spire to the WTC collapse time, the penthouse to the WTC 7 collapse time and my grandma knitting a sock to both.

ANOK, NO they did not. They dismissed pancaking as the INITIATOR of the collapse.

After the initiation they relied on crush-down, not pancaking. The mechanism is not the same.

Originally posted by GenRadek
ANOK, NO they did not. They dismissed pancaking as the INITIATOR of the collapse.

Nonsense pancake collapse is NOT an initiator. Something else has to initiate a pancake collapse.

How many times do you need to be corrected before it sinks in? Or do you just enjoy lying?

Lying about what? You're the one making things up.

reply to post by Darkwing01


Not only that, but the rubble pile of 110 story building was no higher than the lobby levels...

reply to post by wmd_2008

Well maybe you should have looked at some of MY earlier posts mate!!!

Hardly necessary. I'm here to debate facts not credentials. I have no desire to prove I have the structural engineering credentials I say I do, I am merely offering physics based observations (which seemed to offend you somewhat ).

My JOB IS TO ADVISE ARCHITECTS AND ENGINEERS on selection of STRUCTURAL fixings mate

Like a salesman? Engineers deal with representatives from structural element suppliers all the time. Did windows turn on sticky shift keys or are you mad?

sometimes to destruction!!!

Sounds impressive.

I show them and the grunts what to use and how to use and install them properly just to correct YOUR misinformed assumption of what I do!!!!!

Alright mate. Your job still doesn't sound like it requires a particularly deep understanding of how physics relate to structural behavior. You previously even went so far as to mock those of us who work behind a desk and get paid to exercise our brain.

Worked for a sturtural steelwork company YES a structural steelwork company

A structural steelwork company you say?

I suggest you look here to learn something about how YOU ACTUALLY work out dynamic loads!! and if you paid for your EDUCATION get a refund if you can!!!

Actually guy, you are the one who is confused as to the implications and application of Newton's second law of motion. Therefore I won't be clicking the link. Why don't you address the explanation I gave you in my post?

I do know what I am talking about and I am on here to educate and inform!!!!

The biased and ill-informed education you are dishing out is doing no-one any favors. Some of us are here to debate with other informed and intelligent members and do not insult everyone who oppose our views. This is because we are not bias or loyal towards any particular side and give priority to the quest for truth. It was really not necessary to devote your entire post to attempting to prove how much of a reliable authority the education you are offering comes from. Facts always speak louder than credentials.

If you still believe my assertion (that the top section only applied an average crushing force on the lower structure of about 1/3rd of its stationary weight) to be incorrect, why don't you prove that it can't be the case and possibly provide your own figure for the average force applied by the top section as it accelerated through the undamaged lower structure? I'm sure the people you are educating would appreciate some proofs so they can form their own opinion rather than relying on too much blind faith. If you wish I can show how I derived by estimate.

reply to post by ANOK


So you decide to come with slander again. That is basically the only way you can "defend" your complete lack of understanding in physics, saying that other don't understand it either. Well too bad for you, I do understand a lot of physics, at least a hell lot better than you. What is your education anyhow?

Lets review your claim:

There was not enough mass in the top to break the connections, the holding force of the connections would be more than than the force of the dropping top.

Are you serious? The connections, designed to hold up the floor itself plus the live loads and some safety factor, is also capable of holding 15 additional floor plus live loads, all the steel columns in the top, plus a steel mast? This doesn't even has to do with a complete lack of understanding in physics, but with a complete lack of understanding in general. Did you come up with this yourself or did you read is somewhere?

reply to post by ANOK


No Anok, again you don't understand the most general and simplest things. "Pancaking" as initiator means that the floor connections of a single floor failed, initiating the collapse. The NIST theory is that the columns failed, initiating the collapse.

I am under the impression that you have no clue what this distinction even means. Do you know what the columns are? Do you know what the floor connections are? Do you know what the floors are?

reply to post by DrinkYourDrug




I wasn't mocking engineers mate but in your case if you are one please send me a list of any structures YOU WORK ON SO I AM NEVER ON OR IN ONE!!! it was directed to all the people on here that NEVER do anything connected to this in their day to day lives! also I hope your bosses dont find out about your posts so please tell everyone here looking at this cross section detailing the truss connections what actually holds sorry held the floors of the Towers in place!



Again with your obvious total misunderstanding of a DYNAMIC LOAD load can you answer this if as you claim the mass only generates 1/3 of its static load what would happen to you in this situation?

You hold your arms perfectly straight above your head with that 50lb weight and its raised 12ft above you the height of a WTC floor and its dropped with your arms still perfectly straight ,would that when it hits your hands still seem to weigh 50lb about 16lb as you suggest or a hell of a lot more?

To work out the DYNAMIC load of the floors that fell and hitting the floor below yes they can only hit one floor at a time you need some info this is how its worked out if you are at work I suggest you check with a MORE SENIOR ENGINEER!

To determine the impact force. You NEED the duration of the impact( time ), or the distance over which it occurs.(ie till a component shears/fails)

So basically the time it takes that floor to fail or the distance it moves before it fails (components shear etc can no longer support a load)

If you had the duration of the impact, you would use the definition of force as rate of change of momentum:
F = Δp/Δt where F is the average force, Δp is the change in momentum (m*v), and Δt is the duration of the impact.

If you had the distance over which the impact occurred, you would use the definition of work:
W = F * d where W is the work done (equal to the kinetic energy just before impact), F is the average force, and d is the distance over which the impact occured.

Check that out with someone senior and dont worry this lesson in PHYSICS is free of charge to YOU!!!

Here is a link that calculates said imapct forces.

hyperphysics.phy-astr.gsu.edu...

So lest do a little exercise your 50lb weight is 22.3 kg 12ft is approx 3.7 mtrs LETS say you were really strong and could slow it to a stop over 4 inches 102 mm (0.102 mtrs) lnput the figures in the above link and your 22.3 kg weight generates a impact force over the four inches of 7927 newtons divide that fig by 9.81 to get the force in kg and that is 808kg now under your laws of physics that should have been 22.3/3 = 7.4333kg

Now if YOU think thats WRONG I dare you to try it but please video it and I will also send you a link to the Darwin Awards!

If you dropped on a set of scales would it show you as being heavier or 1/3 your weight DOH!

NOW JUST TO PROVE THE POINT WATCH THIS VIDEO AGAIN. Does the little bag of rice generate a 1/3 of its static load when dropped NO!!!!!!!!

reply to post by Darkwing01


Here you go posted before but you obviously missed that


www.stevespak.com...

Second and third pictures down with description!!!!

Check out last pic at bottom of page.

Originally posted by ANOK

Originally posted by GenRadek
ANOK, NO they did not. They dismissed pancaking as the INITIATOR of the collapse.

Nonsense pancake collapse is NOT an initiator. Something else has to initiate a pancake collapse.

How many times do you need to be corrected before it sinks in? Or do you just enjoy lying?

Lying about what? You're the one making things up.

You really need to read what GenRadek is saying HE SAID

They dismissed pancaking as the INITIATOR of the collapse.

You are saying

Nonsense pancake collapse is NOT an initiator

Whats the difference?

No one thinks the pancake collapse was the initiator of the collapse It was the end result of the STRUCTURAL FAILURE ,that caused the pancke collapse, ie the areas above the impact zones DROPPED.

reply to post by wmd_2008

You hold your arms perfectly straight above your head with that 50lb weight and its raised 12ft above you the height of a WTC floor and its dropped with your arms still perfectly straight ,would that when it hits your hands still seem to weigh 50lb about 16lb as you suggest or a hell of a lot more?

I've already explained the errors in your analogy. Check my previous posts. The gist of it was that for a person to catch the falling mass and decelerate it, they must apply an upwards force greater than the stationary weight of the mass. Agreed so far? Another way of saying this is that if a person attempts to catch a falling mass but fails to decelerate it, they must never have applied an upwards force greater than the stationary weight. See where this is going? I'll assume a lack of response to this point to mean you can't point out any errors in it.

I suggest you check with a MORE SENIOR ENGINEER!

Thanks, but I don't need advice from a steel salesman.

To determine the impact force. You NEED the duration of the impact( time ), or the distance over which it occurs.(ie till a component shears/fails)

Which we obviously don't have and could only estimate with a very sophisticated collapse model
(something not attempted by any investigation). Hence I have been discussing the average load applied. Please stop sidestepping the point I am making and address the issue head-on. The falling top section only applied an average crushing force of about 1/3rd its stationary weight to the undamaged structure bellow. You attempted to ridicule me the first time I asserted this but it's starting to not sound so outlandish now, is it?

Check that out with someone senior and dont worry this lesson in PHYSICS is free of charge to YOU!!!

Diverting from the point I am making and dressing it up as a physics lesson? Very clever.

Here is a link that calculates said imapct forces.

Some of us don't need the internets for help with simple equations.

Now if YOU think thats WRONG I dare you to try it but please video it and I will also send you a link to the Darwin Awards!

Not wrong, just irrelevant. If you read my posts more carefully instead of jumping straight into an emotional response you would have seen that I have been explaining to you how crucial accelerations are in determining the forces acting. Why don't you try coming up with an analogy that actually bears any relevance to a top section accelerating through a lower section as it crushes it?

LETS say you were really strong and could slow it to a stop over 4 inches

As you have demonstrated that you have trouble comprehending the points I make, I'm trying to make this post really clear. This analogy would be relevant IF the bottom section decelerated the top section. It did not. Therefore this analogy is irrelevant and proves nothing. You see what I'm saying or you want me to explain it further?

If you dropped on a set of scales would it show you as being heavier or 1/3 your weight DOH!

I wrote the same thing I've been harping on about in this post the last time you posted the video of the scales.

NOW JUST TO PROVE THE POINT WATCH THIS VIDEO AGAIN. Does the little bag of rice generate a 1/3 of its static load when dropped NO!!!!!!!!

That's because the rice is decelerated, guy. Find me a video of a bag of rice accelerating through some scales and then I'll be impressed.

reply to post by DrinkYourDrug


You have a reading problem at what point did I say I was a steel salesman?

There is a deceleration as the falling mass impacts everyfloor on the way down very very small the only thing that resist the downward force is the floor connections YOU know the bit that holds the floor up but as soon as the impact force exceeds the strength of the connection the connection will break that floor then joins the falling mass which although traveling slightly slower now has a far greater mass and the process repeats!!!

So do you want to explain to every one why the video of the rice bag shows a higher load when fall than at rest ?

OHTHATS RIGHT YOU WONT BECAUSE IT SHOWS YOU ARE WRONG!

The scales show the increase IN LOAD THATS THE WHOLE POINT!!!!

None of the floors during the collapse just moved out the way they were overloaded and the connections failed!!!


By the way the example of the 50lb is a good example YOU would be the floors below impact the mass falling would be the top floors and you would be crushed if you kept your arms rigid. IF that would not be the case film it or prove it using your best physics after all the link I gave was to a physics site or are you claiming they are wrong!!

Originally posted by ANOK

Originally posted by GenRadek
ANOK, NO they did not. They dismissed pancaking as the INITIATOR of the collapse.

Nonsense pancake collapse is NOT an initiator. Something else has to initiate a pancake collapse.

How many times do you need to be corrected before it sinks in? Or do you just enjoy lying?

Lying about what? You're the one making things up.

So why are you saying that NIST dismissed pancaking, whenever someone mentions that pancaking occurred? It sounds to me as if you are insisting that pancaking did not occur at all. But it did. NIST stated that the failure of the exterior columns bending inward caused the collapse. The floors proceeded to pancake afterward. Are you denying that pancaking occurred at all?