What about the WTC 1 Spire?

reply to post by ANOK

rigid objects like chains

What? Chains are the farthest thing from rigid! I'm not sure what you're trying to say, but perhaps it could use some revisions or clarifications.

Originally posted by ANOK

You need to show me those models mate. I have yet to see one in over eight years, and how many times have I mentioned this?

You have been shown them many time, you just ignore them. Just a random one:

www.civil.canterbury.ac.nz/fire/pdfreports/cwastney_02.pdf

I can post quite some more as this is a well researched phenomena. But we all know you will not read it, ignore it, and come with the same nonsense all over in some days. But just in case anyone else is wondering I posted an example anyhow. Though for interested minds its just a 5 second google search away.

Rigid chains is a good one by the way. At least you are funny.

Originally posted by DrEugeneFixer
What? Chains are the farthest thing from rigid! I'm not sure what you're trying to say, but perhaps it could use some revisions or clarifications.

DOH!

Rigid as in rigid links, as in not SAGGING from heat. In other words if you put a load on a chain it will not stretch.

Put a load on a truss or beam SAGGING from heat the weight will cause the beam to sag, stretch, more. The force of the weight will be taken up by the sagging, not by putting more force on what it's attached to.

If you can't understand these simple principles then it's no wonder you buy into the OS so easily.

Originally posted by ANOK

DOH!

Doh? How are we supposed to know what you mean to say? You are wrong about most things. Anok, is gravity an internal force or external force in a building collapse? Does conservation of momentum apply or does it not?

Put a load on a truss or beam SAGGING from heat the weight will cause the beam to sag, stretch, more. The force of the weight will be taken up by the sagging, not by putting more force on what it's attached to.

The whole point is, and the thing that you can't seem to figure out, is that the force is a vector. When the trusses are heated, and the trusses become soft and start acting as a catenary, the direction of the vector changes. The magnitude does not.

But who am I kidding. You have been explained so many times now. And you have been shown so many papers or other scientific material that confirms this, that I do not believe anything can possibly change your mind.

Originally posted by DrEugeneFixer

Originally posted by Another_Nut
reply to post by Alfie1
Now post collapse what physics do you think brought the spires straight down?
.

Check out Euler's column buckling equations.Link

parse it out and what you'll discover is that if you double the unbraced-length of a column, that column's ability to carry a load is reduced not to 1/2, but to 1/4 of it's former capacity. Triple the length of a column, and its load bearing capacity is reduced not to 1/3 of its former value, but to 1/9 of that capacity. In other words, the critical load of a column is related inversely to the square of the unbraced-length of the column.

while the perimeter wall stood, the unbraced length of columns in the core would have been the distance between floors, which is 12'6" if I recall correctly. Once the perimeter walls and floors were removed, the unbraced-length of the columns effectively shoots up to 400 feet or more. so, if the unbraced length changes by a factor of 10, the critical load on those columns will be changed by a factor of 1/100!

So the columns of the core, once removed from the context of the bracing provided by the perimeter walls and truss/floors, was only capable of bearing 1% of its former critical load without buckling!

Buckling failure seems inevitable, given this info.

And another thing. You said that the columns were heavily braced, at least to the 60th floor. Were you speaking of the bracing provided by the perimeter columns, through the floor trusses and concrete?

edit on 12/16/2012 by DrEugeneFixer because: (no reason given)

ok now here's the problem . Assuimg this is true we would expect to see the tallest part of the spire give way first .since it would have the longest L and most P .

But we see the opposite . It starts in the lowest and the tallest is the last . And notice it doesn't buckle in the middle at any point.

Also notice the color of the concrete dust as the floors are destroyed and compare that with color of the dust that the steel turns into. The "dust falling off the steel" shouldn't be the same color as the steel.

And lastly ,if they bent before giving way then where are all those deformed columns?

Eta. And lastly lastly lol. What about the survivor who rode that last 20 stories of the spire collapse. He says he floated and blacked out. I think he blacked out because the same forces acting on on the steel and concrete were also acting on the atoms in his body.
If it did fall how was he not
a.crushed as the spire fell on him
B.burried after the spire fell on him
C.flattened by a 150+ foot fall?

reply to post by Another_Nut

ok now here's the problem . Assuimg this is true we would expect to see the tallest part of the spire give way first .since it would have the longest L and most P .

Unfortunately, that's not correct. L refers to the total unbraced length of column; it doesn't differ along the height of a column. P is the critical load, not the actual load: the theoretical max load before buckling failure. The actual load will differ, in this case up and down the core columns.

But we see the opposite . It starts in the lowest and the tallest is the last . And notice it doesn't buckle in the middle at any point.

I don't think that's true. There are definitely several core columns that buckled at some point along the middle of their lengths. There are even a few bent into a 'U" or 'J' shape. I'm not sure where these were located, exactly, but not on the very top, where the Columns were 'I" shaped sections, and not at the very bottom, where the columns were much thicker. Look around on ats or google it, if you want the photos. Here's one.

Also notice the color of the concrete dust as the floors are destroyed and compare that with color of the dust that the steel turns into. The "dust falling off the steel" shouldn't be the same color as the steel.

First, I'd say that the steel did not 'turn into dust'; that theory is beyond my threshold for discussion. So if that's what you think really happened, just ask yourself why you even think such a thing is even possible. There is no known mechanism for such a thing to have happened.

Second. Structural steel in occupied buildings is typically spray coated with a greyish cement-like fireproofing layer about an inch or so thick, depending. url=http://en.wikipedia.org/wiki/File:Owsj_deck_fireproofing.jpg]Here[/url] is a picture of it being applied. I belive the practice at the time off wtc construction was to use an asbestos product, but it's the same color, anyway. That should be food for thought.

And lastly ,if they bent before giving way then where are all those deformed columns?

See above. If you think there were no deformed columns, you're not looking.

Eta. And lastly lastly lol. What about the survivor who rode that last 20 stories of the spire collapse. He says he floated and blacked out. I think he blacked out because the same forces acting on on the steel and concrete were also acting on the atoms in his body. If it did fall how was he not a.crushed as the spire fell on him B.burried after the spire fell on him C.flattened by a 150+ foot fall?

I have no idea whether that story is true or not. The only forces acting on his body, the steel, and the concrete, were those of gravity and potentially, impacts.

It's starting to seem like you're a fan of Dr. Judy Wood. The woman has lost her mind; she suffered some kind of mental damage while she was in a coma. If there were some mysterious forces at work that saved this man, it would seem that they neglected to save all of the other people in the area, for some reason.

Anyway, if you're at all serious about understanding this stuff, you need to dig deep and pick up a structural design texbook, and study it, just as though you were in school, doing all the math problems, etc. There's no way you're going to learn enough by reading ATS to even begin to understand the collapses. That's the sad fact.

reply to post by DrEugeneFixer

P is just the load and is changable. Pcr is critical load . Read your link
L will differ between columns. And once a column buckles any standing steel has to be recalculated

Therefore the lowest columns has shortest L and lowest P and would reach Pcr harder if at all.

The highest columns would have longest L and highest P And would reach Pcr easier

That means the taller parts buckle first. now you can say you dont think this is true but that doest make it so

And the fact there is no KNOWN mechanism is by no means evidence there is NO mechanism

If you wont even entertain the thought that they turned to dust then it seems to me that any evidence shown to you in favor of the disappearance will just be ignored or fitted into what you believe happened.

the story of the Survivor is true. What physics kept him alive for that fall? The story and book are easily findable. He was even on Today.

Lastly I don't need space lasers. I've heard of a story that Tesla almost shook a building apart without them.

.

reply to post by Another_Nut

the story of the Survivor is true. What physics kept him alive for that fall? The story and book are easily findable. He was even on Today.

Myth / Urban Legend

Man rides debris to the ground

As for Dr Judy Woods. I recommend you watch that YT vid of her being interviewed. She's certifiable if you ask me.

Originally posted by samkent
reply to post by Another_Nut

 

the story of the Survivor is true. What physics kept him alive for that fall? The story and book are easily findable. He was even on Today.

Myth / Urban Legend

Man rides debris to the ground

As for Dr Judy Woods. I recommend you watch that YT vid of her being interviewed. She's certifiable if you ask me.

You sir are wrong . Search ats for "9/11 surfer" or google it. I assure you he is very real.

reply to post by Another_Nut


First a clarification: in the context of the Euler equation, we have to consider the columns as being continuous elements that extend the height of the spire, from top to bottom- it's not a meaningful statement to distinguish between 'lower columns' and 'higher columns'; when connected together, whether by welds or by bolted plates, they will act as a single column.

P is just the load and is changable. Pcr is critical load .

I should have written:

Pcr is the critical load, not the actual load

But anyway, there is no term in the equation 'P' sans subscript, so when I read your note, I was assuming you meant Pcr, and responded without referring to the link.

P is just the load and is changable.

There is no term 'P' sans subscript in the equation, therefore the meaning of your statement is entirely unclear.

Read your link L will differ between columns.

True, some of the spire columns were longer than others, so they would have a higher unbraced length. But the unbraced length of ALL of them was increased by a factor of more than 10, so their Pcr would have been reduced to a tiny fraction of its former value.

And once a column buckles any standing steel has to be recalculated

Once a column buckles, it's game over.
The spire collapses.
No part of that column from the top to near the bottom is going to remain in place undamaged for us to do a second round of calculations.

Therefore the lowest columns has shortest L and lowest P and would reach Pcr harder if at all.

like I said before, it's a meaningless distinction to refer to 'lower columns' they're connected to the upper columns , and in the context of the Euler equation, must be considered as a unit, with a single value of 'L' for each column, from base to top of it's height in the spire. But if you want to discuss the load borne by a segment of the columns, the lower portions clearly bear a higher load, not a lower one, because the lower portions are holding up the upper portions.

The highest columns would have longest L and highest P And would reach Pcr easier

see above, you're confused, and are thinking about this backwards.

That means the taller parts buckle first. now you can say you dont think this is true but that doest make it so

Meaningless statement. There are no 'taller parts' in the context of the Euler equation.

And the fact there is no KNOWN mechanism is by no means evidence there is NO mechanism

If you wont even entertain the thought that they turned to dust then it seems to me that any evidence shown to you in favor of the disappearance will just be ignored or fitted into what you believe happened.

If you refuse to consider the possibility that I am a little green man on mars, typing this with fourteen fingers, you will just ignore any evidence or fit it into your 'faith based' belief that I am a human being with ten fingers.

the story of the Survivor is true. What physics kept him alive for that fall? The story and book are easily findable. He was even on Today.

I don't care about the story of this man. If you want to make a case for mysterious forces at play, you need to show how they were operating on the building, not ask people to explain random things you don't understand.

Lastly I don't need space lasers. I've heard of a story that Tesla almost shook a building apart without them.

Well, if you heard a story then I guess you can be satisfied that that's what happened But hang on a second. how does this Tesla device explain your surfer-man?

consider this post stricken from the record. It concerned a red-herring side issue.

Originally posted by DrEugeneFixer

Originally posted by Another_Nut

Originally posted by samkent
reply to post by Another_Nut

 

the story of the Survivor is true. What physics kept him alive for that fall? The story and book are easily findable. He was even on Today.

Myth / Urban Legend

Man rides debris to the ground

As for Dr Judy Woods. I recommend you watch that YT vid of her being interviewed. She's certifiable if you ask me.

You sir are wrong . Search ats for "9/11 surfer" or google it. I assure you he is very real.

Yeah, you won't find any false information on ATS or the internet.

Are you calling Mr.Buzzelli a liar? Are you calling the Todays show hoaxers? If you dont believe him then nothing I say could ever convince you.

I would like to get this straightened out before I respond to the rest.

Originally posted by Another_Nut

Are you calling Mr.Buzzelli a liar? Are you calling the Todays show hoaxers? If you dont believe him then nothing I say could ever convince you.

I would like to get this straightened out before I respond to the rest.

This is a totally tangential side discussion. Nobody knows how this man somehow survived, not even him-he was knocked unconscious during the collapse, not to mention breaking his foot. Speculate all you want about unknown mysterious forces that only saved him and the person right next to him, who suffered a crushed leg and was trapped in the debris.

I don't care. This has nothing to do with the collapses of the spires. Let's keep it on-topic.

For those that are having trouble visualizing why the spire fell down the way it did:



pay close attention to how the center columns kink out and the top falls down. This may have very well caused the effect we saw with the Spire falling "straight down" during collapse!

Originally posted by DrEugeneFixer

Originally posted by Another_Nut

Are you calling Mr.Buzzelli a liar? Are you calling the Todays show hoaxers? If you dont believe him then nothing I say could ever convince you.

I would like to get this straightened out before I respond to the rest.

This is a totally tangential side discussion. Nobody knows how this man somehow survived, not even him-he was knocked unconscious during the collapse, not to mention breaking his foot. Speculate all you want about unknown mysterious forces that only saved him and the person right next to him, who suffered a crushed leg and was trapped in the debris.

I don't care. This has nothing to do with the collapses of the spires. Let's keep it on-topic.

I think the words of a man who was inside the spire when it fell is perfectly on topic. He says it was like freefall till he blacked out. And that's when he had 20 or so floors above him disappear. When he woke up he was on top of the pile. How does that work?

reply to post by GenRadek


look at how much horizontal movement it does have .it starts at the edge of the house and the top falls right
Around the peak of the A frame roof. start and I have a feeling the only reason it didn't fall further over is due to multiple explosions along the tower ( though I am just guessing on number of charges.) or were the guide lines still attached?

Originally posted by Another_Nut
I think the words of a man who was inside the spire when it fell is perfectly on topic. He says it was like freefall till he blacked out. And that's when he had 20 or so floors above him disappear. When he woke up he was on top of the pile. How does that work?

You just want to change the topic under discussion. I'm not going to play along.

reply to post by Another_Nut


I was pointing out how the spire and the columns themselves may have fallen or behaved in that dust cloud we couldnt see. The connected columns may have done something similar to make it look like it fell "straight down."

Originally posted by DrEugeneFixer

Originally posted by Another_Nut
I think the words of a man who was inside the spire when it fell is perfectly on topic. He says it was like freefall till he blacked out. And that's when he had 20 or so floors above him disappear. When he woke up he was on top of the pile. How does that work?

You just want to change the topic under discussion. I'm not going to play along.

Are you using the entire core structure as L? Or are you using individual core columns?

Once the spire has appeared dont you have to look at the length of each column to determine the buckle?

So that the lowest columns in the core would have corresponding high Pcr while the tallest columns in the spire would have have a low Pcr

Originally posted by Another_Nut

Are you using the entire core structure as L? Or are you using individual core columns?

Individual core columns are approximately the same length; the same as the overall height of the spire. It doesn't make much difference to 'L', since the columns are continuous.

Originally posted by Another_Nut
Once the spire has appeared dont you have to look at the length of each column to determine the buckle?

Not clear what's meant by this since the columns are all approximately the same unbraced length; the same height as the spire. sure, there's a substantial variation in height, but in terms of Pcr, they're ALL reduced to a tiny sliver of their former selves.

Originally posted by Another_Nut
So that the lowest columns in the core would have corresponding high Pcr while the tallest columns in the spire would have have a low Pcr

There are no high or low columns, when it comes to a buckling analysis. Their unbraced lenghths all extend from the ground level to their tops.