Why Should the WTC Towers Suffer Complete Collapse?

reply to post by Richard Gizinu


It wasn't in that article. I had read up on this story a while ago and that's why I was so quick to be able to source it. I can't remember what it was. Something about the support they used to hold the skywalk up wasn't installed correctly (but it was installed by the building plans) and because of that it wasn't able to hold nearly the weight it was supposed to.

Edited to clarify:
It was installed as the building plans specified, but the building plans had it set up to be installed incorrectly.

[edit on 23-1-2008 by Sublime620]

Originally posted by Sublime620

It wasn't in that article. I had read up on this story a while ago and that's why I was so quick to be able to source it. I can't remember what it was. Something about the support they used to hold the skywalk up wasn't installed correctly (but it was installed by the building plans) and because of that it wasn't able to hold nearly the weight it was supposed to.

Edited to clarify:
It was installed as the building plans specified, but the building plans had it set up to be installed incorrectly.

LOL, actually, now I think i remember seeing this on the History Channel or such about engineering disasters.

There was an install problem and the contractor got a variance for the bolt to span 2 floors.... or like you said, it was installed backwards, but according to the variance.....

Like I said, it points to the fact of how rigorous QA/inspections are and how good these contractors are.....

Originally posted by Richard Gizinu
Yep, we disagree. Especially since I was specifically asking for instances where the construction/inspections were documented to be at fault.

Why would it be documented and then not fixed? That would put the contractor at serious risk. They like the brunt of everything to be on the shoulders of the engineer/architect. Every time I see something not going right, I document it and then it gets fixed. But, as I've been trying to point out, inspectors are not there every single second of the day and sometimes things get missed.

I pretty much agree with the rest of your post though.

Originally posted by Richard Gizinu
Like I said, it points to the fact of how rigorous QA/inspections are and how good these contractors are.....

Most contractors are very good at what they do. It's an artform. I've seen some contractors with such finesse that it would blow people's mind.

Originally posted by Griff

Why would it be documented and then not fixed? That would put the contractor at serious risk. They like the brunt of everything to be on the shoulders of the engineer/architect. Every time I see something not going right, I document it and then it gets fixed. But, as I've been trying to point out, inspectors are not there every single second of the day and sometimes things get missed.

I pretty much agree with the rest of your post though.

I'm talking about a failure where AFTERWARDS, an investigation into the event discovers that there was contractor/inspector/QA poor quality of work.

Things get missed, hence the infamous "punch list" on homes when the first people move in. But these are minor. The concept that all those core columns were inadequately welded/not to spec is simply not believeable.

The engineers wouldn't have forseen the improbability of what would happen in a global collapse either, so I don't think there can be blame laid on their doorstep.

reply to post by Richard Gizinu


Am I taking crazy pills or aren't you the one that brought that up to begin with? I thought you were the one that said the welds weren't that strong and only about 1/3 deep.

Originally posted by Sublime620
reply to post by Richard Gizinu

 

Am I taking crazy pills or aren't you the one that brought that up to begin with? I thought you were the one that said the welds weren't that strong and only about 1/3 deep.

That's right.

The original statement was that the core columns being in neat, straight pieces was suspicious. Ya know, another "smoking gun".....

The welded area was less able to resist lateral loads than the core columns. That's why they core columns broke up into neat pieces.

But they were welded to spec, so there's nothing suspicious about it.

reply to post by Richard Gizinu


Oh okay. Thanks for clearing that up.

Originally posted by Richard Gizinu

Originally posted by Sublime620
reply to post by Richard Gizinu

 

The original statement was that the core columns being in neat, straight pieces was suspicious. Ya know, another "smoking gun".....

Vertical does mean straight up and down. If not vertical, care to explain in which directions(s) you think they were placed when the towers were erected? While you are at it, why don't you explain your version of how the cores were actually erected, stabilized and by what?

reply to post by Richard Gizinu


The exterior steel primary load bearing walls were designed to take heavy lateral load, and did so extremely well for about 30 years - until 9/11/2001, under highly abnormal circumstances having nothing to do with alleged commercial jetliners and jet fuel.

The core stabilized and was primary gravitational load bearer. The perimeter wall sections were the primary lateral load bearers, with the core being the stabilizer on lateral load.

reply to post by Richard Gizinu


Well... actually I'm a little confused. I can see your point in the top - at the initial collapse. The exterior columns were buckling in, transfering the load to the core columns which weren't designed for that.

So lets just say that happens, the core fails, and it starts tumbling down. Would that be enough force to pancake the remaining floors? Also, that doesn't explain what happened to the core on the remaining lower floors.

Please explain further if you would. Just trying to get a picture of this. Also, I'd like to clarify that I'm not arguing with anyone. I have no engineering background. This just seems like a productive thread that I haven't seen in a while, and I'd like to see real issues discussed instead of bickering.

Originally posted by Sublime620

Well... actually I'm a little confused. I can see your point in the top - at the initial collapse. The exterior columns were buckling in, transfering the load to the core columns which weren't designed for that.

So lets just say that happens, the core fails, and it starts tumbling down. Would that be enough force to pancake the remaining floors? Also, that doesn't explain what happened to the core on the remaining lower floors.

The core columns WERE designed to carry gravity loads, around 50% They were also damaged by the plane strikes and fire. So they failed.

I don't really know the mechanics of the collapse, too chaotic. Just what I see. Like both cores stood for a second or 2 at the end of the collapses. Then they fell too because as you can see in a photo I posted, most of the horizontal core supports/floor beams were removed by falling junk. The bottom several floors of 1 actually never fell, they found survivors there.

I don't know what stripped the floors off those core columns, but logic would say that the falling floors along with all their contents and mechanical equipment - HVAC, elevators, etc popped them off since individual trusses were held on by 5/8" bolts.

The huge drooping plumes,.... Do look like the top floors turn to cement dust,...Where do those top floors go ...There is no reason why those floors and all there office belongings shouldn't be noticeable in the rubble,...After all they were not subjected to that "pile-driver" effect.(?)....But,...somehow it seems everything,...on every floor was 100% destroyed...Only tiny, tiny, pcs...come on.......My guess is there were a doz different types of demo charges used...For whatever the effect...Destroy everything totally,....And make it look a certain way...They certainly had enough time to plan and impliment it...When has a collapse ever been only rubble that is reduced to dust and small parts...??...never...heavy duty beams All breaking at the same time....Everywhere,,.....not to mention sounds of explosions...many sounds of explosions..many coming from low levels,........It did not appear right that morning on TV when we all watched them buildings fall..and it still does not look right when we see them fall again any time we press play......

reply to post by gottago



Here are the fallacies you are spewing itemized.

Here we encounter the basic problem: I do not see any "huge mass falling and pulverizing the mass below." I see the immediate remnants of the upper building mass being ejected outward and the concrete being turned to dust.

Erm. Haven’t been around a building being constructed have you? Messy messy affair that they can’t completely clean up, well probly could but whats the point especially in parts the public will not be going in? between walls etc. Lots of dust that’s what that cloud is, that and the accumulated stuff over the lifetime of the building and etc.
Oh and lets not forget the properties of dry wall.

The majority of the upper building mass simply no longer exists to drive the collapse. It is being strewn across the WTC site.

How does falling concrete pulverize itself? There is going to be a bit of well breaking up after it impacts the one below it but by then it gains the mass of the floor it just impacted when that floor fails as well.
Domino effect.

We also know that the structural members--the core and perimeter columns--become much thicker toward the bottom of the buildings to support the upper mass. Why then, without 1/2, or, about a second later, 3/4 of the upper mass pressing down on them, do the buildings continue to collapse? At their strongest point?

Your saying it was designed to take the impact of all the stuff it was supposed to hold up especially considering some (large amount by this juncture) of the elements of that tangled mass has a fair amount of interia?
Having found the idea of the conrete magically pulverizing itself at impact rather silly? (not calling you silly just the idea)


[edit on 24-1-2008 by WraothAscendant]

Originally posted by WraothAscendant
reply to post by gottago

 

Here are the fallacies you are spewing itemized.

Here we encounter the basic problem: I do not see any "huge mass falling and pulverizing the mass below." I see the immediate remnants of the upper building mass being ejected outward and the concrete being turned to dust.

Erm. Haven’t been around a building being constructed have you? Messy messy affair that they can’t completely clean up, well probly could but whats the point especially in parts the public will not be going in? between walls etc. Lots of dust that’s what that cloud is, that and the accumulated stuff over the lifetime of the building and etc.
Oh and lets not forget the properties of dry wall.

So, the dust that coated lower Manhattan 2-3 inches deep and wafted over the harbor was actually dust from construction they just swept behind the drywall, and the drywall itself? Thanks for clearing that up. I guess this spectroscopic analysis report by the USGS is full of it then.

Interpretation

The total element compositions of the dust samples reflect the chemical makeup of materials such as: glass fibers (containing silicon, aluminum, calcium, magnesium, sodium, and other elements); gypsum (containing calcium and sulfate); concrete and aggregate (containing calcium and aluminum hydroxides, and a variety of silicate minerals containing silicon, calcium, potassium, sodium, and magnesium); particles rich in iron, aluminum, titanium, and other metals that might be used in building construction; and particles of other components, such as computers, etc. Organic carbon in the dusts is most likely from paper, wallboard binder, and other organic materials.

The trace metal compositions of the dust and girder coatings likely reflect contributions of material from a wide variety of sources. Possibilities include metals that might be found as pigments in paints (such as titanium, molybdenum, lead, and iron), or metals that occur as traces in, or as major components of, wallboard, concrete, aggregate, copper piping, electrical wiring, and computer equipment.

It's also interesting to look at the elements that USGS found in that construction dust and drywall:



This is only approximately 1/3 of the chart; it goes on to list such elements as Yttrium, Uranium, Silver, Lanthanum, Vanadium, Lithium, Thorium, Rubidium, Niobium, Scandium, Beryllium, Cesium, Thallium, Cesium, etc.

It certainly is the most exotic leftover construction dust and drywall I've ever heard of.

Thanks for clearing my fallacies up for me. I will spew no more.

The majority of the upper building mass simply no longer exists to drive the collapse. It is being strewn across the WTC site.

How does falling concrete pulverize itself? There is going to be a bit of well breaking up after it impacts the one below it but by then it gains the mass of the floor it just impacted when that floor fails as well.
Domino effect.

All this pulverization is occurring in mid air by the collapse itself, by materials smashing other materials--such as copper pipes and computers, as the USGS notes above--into dust as they fall. I see. How interesting. Learn something new every day.

We also know that the structural members--the core and perimeter columns--become much thicker toward the bottom of the buildings to support the upper mass. Why then, without 1/2, or, about a second later, 3/4 of the upper mass pressing down on them, do the buildings continue to collapse? At their strongest point?

Your saying it was designed to take the impact of all the stuff it was supposed to hold up especially considering some (large amount by this juncture) of the elements of that tangled mass has a fair amount of interia?
Having found the idea of the conrete magically pulverizing itself at impact rather silly? (not calling you silly just the idea)

Yes I find it rather silly too. To tell the truth, silly in the extreme.

[typos]

[edit on 24-1-2008 by gottago]

reply to post by gottago

All this pulverization is occurring in mid air by the collapse itself, by materials smashing other materials--such as copper pipes and computers, as the USGS notes above--into dust as they fall. I see. How interesting. Learn something new every day.

Of course there is going to be alot of pulverization but at the very beginning of the collapse?

It couldn't go from BIG pieces of concrete to little pulverized bits at the very start of the collapse.

The intial dust cloud, I will expand on what I was saying, most likely consisted of mostly drywall, leftover mess from its construction, stuff that accumulated its age dust what-not etc, ash from the fires and some concrete dust (on the levels you propose though I think not likely).
Or are you going to tell me they somehow was able to stop time and get a sample of the initial cloud?
The dust that settled is not EXACTLY the dust you see in the opening stages of the collapse. Seems me its a matter of common sense.

I saw critiqing (methinks i misspelled) the photo you posted that showed AT THE VERY BEGINNING the collapse. Which is what your saying without saying it. It was a fluid situation otherwords IN MOTION and changing as the seconds ticked by.
.

Oh and

gypsum (containing calcium and sulfate);

IS USED TO MAKE DRYWALL.


And generally large scale pulverization of concrete (I think) would happen after the concrete had absolutely no where to go, you would have some in the fall of course. But not so much at the beginnning. I am, of course, not a physics professor but that sounds more plausable to me.

See what I am saying now?








[edit on 24-1-2008 by WraothAscendant]

Originally posted by WraothAscendant

Of course there is going to be alot of pulverization but at the very beginning of the collapse?

It couldn't go from BIG pieces of concrete to little pulverized bits at the very start of the collapse.

So you're okay that at the end of the collapses, you would expect to find computer components, wiring, copper pipes, etc. being pulverized to the point that the USGS can scoop them up as particulate from sites across lower Manhattan and do spectroscopic analysis of them?

If that's what you want to believe, hey, go ahead.

The intial dust cloud, I will expand on what I was saying, most likely consisted of mostly drywall, leftover mess from its construction, stuff that accumulated its age dust what-not etc, ash from the fires and some concrete dust (on the levels you propose though I think not likely).
Or are you going to tell me they somehow was able to stop time and get a sample of the initial cloud?

I saw critiqing (methinks i misspelled) the photo you posted that showed AT THE VERY BEGINNING the collapse. Which is what your saying without saying it. It was a fluid situation otherwords IN MOTION and changing as the seconds ticked by.

Both photos posted are well into the collapse, a bit less than halfway. But I'm trying to understand the relevance of your argument: how is hitting the ground going to turn the aforementioned metals and building components into fine particulate? You could take that copper pipe or wire and drop it from the height of the WTC towers repeatedly, until the end of time, and you will not turn it to particulate.

Oh and

gypsum (containing calcium and sulfate);

IS USED TO MAKE DRYWALL.

Yes, you are correct about that. Silver, copper or yttrium, however, are not.

Originally posted by Richard Gizinu
The concept that all those core columns were inadequately welded/not to spec is simply not believeable.

The engineers wouldn't have forseen the improbability of what would happen in a global collapse either, so I don't think there can be blame laid on their doorstep.

I believe we are kinda arguing the same thing.

The welds would have been designed for compression. They probably didn't take into account lateral loads and moments being placed on them.

So, you are probably correct that the welds were probably up to spec.

BTW, I wasn't saying that the welds were positively out of spec. Just that it is strange that welds are usually designed to be stronger than the steel but in this case they failed at the welds. But, were the welds designed for the lateral loads? Who knows.

Originally posted by Griff
But, were the welds designed for the lateral loads? Who knows.

I kinda doubt it, given the stated design.

The core took 50% of the gravity loads and the exterior columns took the other 50% of the gravity loads and all the lateral loads.

The core columns would have to "sway" along with the rest of the building during high winds, etc. But from what I can gather, the core acted like the fulcrum on a teeter totter during these conditions, for lack of a better term. So here's a question - would the core columns need to be welded 100% under those conditions?

reply to post by Richard Gizinu
Would this be the pic of a column you referred to earlier?



What's the chance of the plane impact breaking core column welds rather than severing the columns themselves. I doubt such an event was really planned for and could leave the building standing there with a spinal fracture depending on much weaker peripheral steel components acting as splints to hold it in place.