World Trade Center Construction Flaws Revisited

[THE BIG APPLE]

Originally Posted by dchan

There you go again. In your previous post, you acknowledged that, yes, steel can indeed be weakened before it reaches its melting point. Instead, you realized that your argument was flawed (based on your own calculations, no less) and chose to repeat your previous mantra of "the steel didn't melt" even after you had already acknowledged that steel can be weakened well below its melting temperature.

I thought you had become more reasonable when you made the effort to type in all of your calculations. But it's pretty clear that you'll say anything to save your faltering argument at this point, no matter how ridiculous. I mean, in your last sentence, you're claiming that all of the office furniture, papers, and other office material in the towers basically disintegrated into nothingness!

Yes steel can be weakened before melting point. BUT I stand by my argument (the steel didn't melt), especially since it was burning at the 600-800 F range (which is FACT and something you standby as well) . Now how many floors did each twin have? 110 (actually 109, 110 was outdoor observation). Now plane 1 (north tower) hit the building at the 80th floor mean.

Now you're saying that something in the (C) and (D) happened and I'm saying something in the (A) and (B) happened.



But lets say the load of the 30 extra floors above the impact range did weaken the steel. (Which is like saying take a chunk of steel that equals to the height of 30 floors, and put it on the roof of the JP Morgan Chase Tower in Houston. Will the JP Morgan Chase Tower fall?) BUT there were 79 STRONG floors under the impact zone. How did they; including the strong steel Reinforced, cast concrete, tubular core under the impact zone just disappear after the collapse. The collapse should've slowed down from the undamaged 70+ floors under the impact zone (keep in mind buildings CAN NOT fall at free fall speed, that violates the LAWS of physics, equivalent to me jumping out of a second story window and reaching the ground in 3 seconds, remember this is NOT a nut job conspiracy theory, this is the laws of physics two complete different things)(Conspiracy theory is like someone believing in the Illuminati FYI). Now if you can prove this to me, as I have proven to you countless times. Why was there THIS:



When there should've been this:



(21 story building)



(How a STEEL building collapse looks)



(1918)

JUST explain the above, and I will automatically believe you, and NEVER post in this thread. Tick, tock.

[dchan]

The problem here is that you're comparing two different structure types. Not all steel building structures are the same, and they don't collapse in the same way when they fail. The one that you're using in your argument is a standard steel skeleton structure, in which steel beams and columns criss-cross across a grid in a regular pattern. Another (the WTC towers) consisted of a steel core structure tied by floor plates and steel joists to perimeter columns, a structure designed explicitly to maximize the rentable floor space.

With the standard grid-based steel skeleton, one side of the building can be heated and collapse while the other side remains relatively unaffected and can remain standing (as seen in your 3-D structural program renderings you posted). This is especially true if the steel fireproofing on the other side remains intact.

I remember reading about old wooden fighter airplane whose structure consisted of a wicker-like crisscrossing wooden frame. The advantage to this design was that if one part of the plane was hit, the wicker-like structure in the area would simply break off without affecting the rest of the airplane's structure. The rest of the plane's wicker-like structure will remain intact, and the airplane can continue to fly without too much trouble. The standard grid-based steel skeletons are sort of like this in this regard.

The tube-frame system works differently. Instead of a grid of beams and columns supporting the structure, the main supporting elements are now the outer perimeter structure and the inner core structure which are tied together with floor trusses. The structural elements behind this design are also behind why the towers collapsed as they did.

Whereas the various parts of the grid-based steel skeleton act relatively independently of each other, the the tube-frame system in the WTC towers work together to compromise for the fact that there aren't regular steel column and beam running throughout the building. As such, they also assist towards the collapse of the entire structure if some of the elements are compromised as they were on 9/11. Once too many of those elements are compromises and start to collapse, the structural elements that once worked to hold together the building are still there also to hold together the building. Only now, parts of the building are failing, and as they collapse, they pulling and push on the other elements that continue to hold together the building. As a result, the other parts of the building now start to collapse as well.

In essence, the structural elements in the WTC towers worked in harmony to resist gravity and lateral forces during normal operation. But during 9/11, they worked in harmony to collapse together as well.

From this lesson, structural engineers have learned to avoid tying together their building frames too excessively and without safeguards against progressive collapse. As such individual structural beams are now designed to fail without affecting the adjacent structural components much.

[THE BIG APPLE]

^ As you said before, nice info and all but it's still missing a piece and thus 100% inaccurate. WHY wasn't there a sandwich of floors piled on top of each other? That's one thing I asked that you didn't explain. You just twisted the story, and made it into something else. I know that the WTC and normal steel skeleton buildings have a different structure, and I only used that diagram to show, that any steel building will have pile upon pile of floors jumbled on top of each other after a COLLAPSE whether it's an interior steel skeleton structure, or load bearing wall structure, or most commonly used X-brace structure. Just explain why there wasn't piles of floors, since 70+ floors (not 70+ floors worth of load bearing structure) were fine. That's one thing you have failed to explain. Why weren't there 110 floors stacked on top of each other. Explain this and you will see the eternal light. If you give a good explanation you will get a thank you from me, and most importantly from god.

[dchan]

A) None of your examples you listed had a neat pile of floor stacked on top of each other (and I'm not even sure the 1918 example you showed is even a steel building, since you didn't provide links to anything). They all look kind of messy to me.

B) Scale. Your examples are tiny and very short compared with the WTC towers. I can't totally picture the force of a tower that size as it's collapsing, and it seems, neither can you. But it's a lot of force, a lot of mass, and a lot of kinetic energy being imparted as they come down. And you expect a neat pile of 110 floors stacked neatly on top of each other like CD jewel cases from all that? That's laughable.

C) What were the floors made of? The floor slabs used in the towers were 4-inch lightweight concrete slabs. This isn't exactly the most robust material here (6 inch concrete floor slabs is the usual standard), and you expect it to stay together in one piece like a CD jewel case after falling from hundreds of feet in the air, crashing onto the ground, and receiving the force and weight of the rest of the building to fall on top of it?

Also, I love your choice of words here. Because I'm supposedly missing a piece of information in my post, my position must then be "100% inaccurate". Learn to be a bit less hamfisted before you try to debate someone next time.

[THE BIG APPLE]

None of your examples you listed had a neat pile of floor stacked on top of each other. They all look kind of messy to me.

The 21 story building looks perfectly neat, and all the debris is piled up in one place. The twins aftermath is what looks messy.

Scale. Your examples are tiny and very short compared with the WTC towers

That's exactly my point. The 21 story building was a steel building in Mexico, and it's a pretty neat pile. What I'm trying to say is the Twin Towers has 5 times as many floors (x2), meaning what you see in the photo (of the 21 story building), you should've seen in aftermath 9/11 pics TIMES 2 (220 floors).

you expect it to stay together in one piece like a CD jewel case after falling from hundreds of feet in the air, crashing onto the ground, and receiving the force and weight of the rest of the building to fall on top of it?

NOT falling to the ground. Falling on the the floors underneath, and then (should've) the pancake effect. If human(s) could survive WHEN (after) the towers fell, then the concrete could survive too (case in point ex. Pasquale Buzzelli fell 15 stories from the 22nd floor to the 7th floor. John McLoughlin, and William Jimeno). That's just three PEOPLE whom anatomies are made with flesh, and blood, NOT concrete. I'd say we should've seen an appox. 78,000+78,000 tons of steel piled up and 200+ ft of piled up debris from both towers. Yet everything just seemed to be spread. AGAIN you're hiding from the question, and until you don't answer it, or change it into a completely different topic, I have no discussion to discuss or time to waste. I'll happily discuss all day IF you provide answers, and if you don't have them then don't respond. OK. One last time. Why was there NO pancakes (of steel x2) in the collapse of the twin towers?

[wong21fr]

A little learning is a dangerous thing;
drink deep, or taste not the Pierian spring:
there shallow draughts intoxicate the brain,
and drinking largely sobers us again.

[dchan]

Originally Posted by THE BIG APPLE

The 21 story building looks perfectly neat, and all the debris is piled up in one place. The twins aftermath is what looks messy.

That's exactly my point. The 21 story building was a steel building in Mexico, and it's a pretty neat pile. What I'm trying to say is the Twin Towers has 5 times as many floors (x2), meaning what you see in the photo (of the 21 story building), you should've seen in aftermath 9/11 pics TIMES 2 (220 floors).

NOT falling to the ground. Falling on the the floors underneath, and then (should've) the pancake effect. If human(s) could survive WHEN (after) the towers fell, then the concrete could survive too (case in point ex. Pasquale Buzzelli fell 15 stories from the 22nd floor to the 7th floor. John McLoughlin, and William Jimeno). That's just three PEOPLE whom anatomies are made with flesh, and blood, NOT concrete. I'd say we should've seen an appox. 78,000+78,000 tons of steel piled up and 200+ ft of piled up debris from both towers. Yet everything just seemed to be spread. AGAIN you're hiding from the question, and until you don't answer it, or change it into a completely different topic, I have no discussion to discuss or time to waste. I'll happily discuss all day IF you provide answers, and if you don't have them then don't respond. OK. One last time. Why was there NO pancakes (of steel x2) in the collapse of the twin towers?

Now you're just making up numbers and figures that sound nice in your head. How, pray tell, did you come up with your claim that the way the tower debris was strewn was equivalent to a 220 story tower collapsing? And what does the rather miraculous survival of a few people falling several stories (God bless them) have to do with the intact survival of an entire concrete slab plate of the towers? An human sized chunk of reinforced concrete may likely survive the same fall intact, but you're asking for a whole floor plate to survive intact?

And if you want some numbers, how about the amount of energy released as the towers collapse compared with the collapse of this Mexican office building (or whatever the building is - you didn't provide a link)? By my very conservative estimates, the collapse of each tower released roughly 30 times more kinetic energy than the collapse of the Mexican building. Do you not believe a building collapse that released 30 times (again, a conservative estimate) more kinetic energy would result in a far, far messier debris pile?

The other problem is that you still believe in the pancake theory, that the collapse was due to each floor progressively piling on top of the floor below. This theory has largely been disproved by experts. The NIST investigation points to a different theory - that the sagging and weakened trusses pulled the core and perimeter columns together. I believe in the latter theory because it goes hand in hand with my point a few posts above. The towers were designed for the core and perimeter structure to work hand-in-hand to provide gravity and latter support during normal operations. However, this design also worked against the tower after the fireproofing was all blown away because the trusses connecting the core and perimeter, which were designed to connect the two so that they could support the building together, now instead pulled them together to precipitate the collapse of the towers.

[THE BIG APPLE]

Now you're just making up numbers and figures that sound nice in your head. How, pray tell, did you come up with your claim that the way the tower debris was strewn was equivalent to a 220 story tower collapsing?

I NEVER said that (read carefully), BUT you just answered your own miscommunication ridden-ed question. One tower had how many floors (110). The other tower had how many floors (110). 110+110=220. Simple (no including such elements as antennas, broadcasters, exterior mass bearing columns, etc.). The debris in a collapse of the twin towers would've equaled appox. 200+ ft (as I stated!).

By my very conservative estimates, the collapse of each tower released roughly 30 times more kinetic energy than the collapse of the Mexican building

Ofcourse there was more kinetic energy. What has more (movement) kinetic energy. A 21 story building collapsing at 8 seconds, or two 110 story buildings collapsing at 8 seconds.

The other problem is that you still believe in the pancake theory

And so do almost all the professors at MIT.

The NIST investigation points to a different theory - that the sagging and weakened trusses pulled the core and perimeter columns together. I believe in the latter theory because it goes hand in hand with my point a few posts above. The towers were designed for the core and perimeter structure to work hand-in-hand to provide gravity and latter support during normal operations. However, this design also worked against the tower after the fireproofing was all blown away because the trusses connecting the core and perimeter, which were designed to connect the two so that they could support the building together, now instead pulled them together to precipitate the collapse of the towers.

Again you're talking about WHY the towers fell. Even if everything NIST stated (as you posted above), that would still constitute pancake upon pancake of floors. Where did all the floors disappear off to (across the street on the WFC, maybe in the Hudson River). There I gave you two choices and you got alot more in your head.

If you need help I'll give the Webster's dictionary definition of two words collapse and explode.

-Collapse: (of a structure) Fall down or in; give way: "the roof collapsed on top of me".

-Explode: Burst or shatter violently and noisily as a result of rapid combustion, decomposition, excessive internal pressure, or other process.

You still haven't explained why there were not piles of floors. I even gave you some extra material for your next post.

[wong21fr]

^Conspiracy theory! Conspiracy theory! Worthless conspiracy theory garbage!

[marvelfannumber1]

@the big apple

Is this the answer you are looking for? So you will shut up and not ruin this thread like you did to MY WTC 7 thread.

http://www.stevespak.com/fires/manhattan/void.jpg

Most of the floors were pulverised the ones that survived (not many) were found piled on top of eachother underground. Atleast what was left of them.