Has Anyone Seen A Realistice Explanation For Free Fall Of The Towers?

[Christophera]

Ok, I'm really having a hard time understanding what your image is supposedly proving.

You've got 2.254 million cubic feet of concrete that no one has ever claimed existed including the structural engineers and general contractors.

Wrong in more than one way.

http://www.ncsea.com/downloads/wtcseerp.pdf

It was designed as a tube building that included a perimeter moment-resisting frame consisting of steel columns spaced on 39-inch centers. The load carrying system was designed so that the steel facade would resist lateral and gravity forces and the interior concrete core would carry only gravity loads.

Dr. Domel received a Ph.D. from the University of Illinois at Chicago in 1988 and a Law Degree from Loyola University in 1992. He is a licensed Structural Engineer and Attorney at Law in the .State of Illinois and a Professional Engineer in twelve states

http://www.didyouknow.org/terrorism.htm

Each of the WTC towers had a double-strength structure consisting of a concrete core supported by a steel structure around the outside.

 

[Alt+F4]

http://www.didyouknow.org/terrorism.htm

Each of the WTC towers had a double-strength structure consisting of a concrete core supported by a steel structure around the outside.

A website run by a poet. Come on, you can do better than that!

 

[maccy]

Wrong in more than one way.

http://www.ncsea.com/downloads/wtcseerp.pdf

It was designed as a tube building that included a perimeter moment-resisting frame consisting of steel columns spaced on 39-inch centers. The load carrying system was designed so that the steel facade would resist lateral and gravity forces and the interior concrete core would carry only gravity loads.

Dr. Domel received a Ph.D. from the University of Illinois at Chicago in 1988 and a Law Degree from Loyola University in 1992. He is a licensed Structural Engineer and Attorney at Law in the .State of Illinois and a Professional Engineer in twelve states

That document descibes the rescue operation and the role of strcutural engineers in it. It is not a report about the construction of the towers. The quote that you choose is in the introduction and does not site any other document.

The docuement has no authority.

It also doesn't descibe a core as you claim it to be and it doesn't answer TheAlmond's questions.

 

[The Almond]

Wrong in more than one way.

http://www.ncsea.com/downloads/wtcseerp.pdf

It was designed as a tube building that included a perimeter moment-resisting frame consisting of steel columns spaced on 39-inch centers. The load carrying system was designed so that the steel facade would resist lateral and gravity forces and the interior concrete core would carry only gravity loads.

Ok, so why do you continually post about the non-existence of a steel framed core? I didn't claim that there was no concrete in the core, but rather that your claim that there was no steel was ludicrous. And what's with the picture? What are you trying to prove with the picture?

As for your link. Read in context, the report does not state that there were no steel columns at the core. Also, noting that the core carried "only gravity loads" would prove, quite to the contrary, that the concrete core you described was never used as a shear wall.

http://www.didyouknow.org/terrorism.htm

Each of the WTC towers had a double-strength structure consisting of a concrete core supported by a steel structure around the outside.

Yet another group acknowledging the steel core. Why did you post that one?

 

[Architect]

To be honest, I'm amazed you guys keep trying to talk to this loon....

 

[maccy]

More information about the Domel paper.

Beachnut wrote to the NCSEA about it, and got this reply:

Keith-

NCSEA forwarded your question to me. I was the author of the document you are questioning.
You are correct that the twin towers did not have a concrete core. However, they, did have a well-defined core consisting of conventional steel framing supported by steel columns. Generally, horizontal framing in the core was not moment-resisting framing, though semi-rigid (type PR) connections were used for some of this framing. Thus, the statement that the core structure was not designed for lateral resistance.

The core framing did play a significant role in resisting collapse, however, after the aircraft impacts and initial damage sustained by these impacts. The core, ultimately, also played a significant role in the collapse. If you would like more information, you may obtain detailed reports at www.nist.gov/wtc

Regards,
Ron Hamburger

http://www.internationalskeptics.com/forums/showthread.php?postid=2079372#post2079372

Domel is a lawyer specialising in structural engineering, so it seems likely that Ron Hamburger supplied the information for his introduction.

As a lawyer, Domel's details are public, so if anybody feels like contact him and asking what he thinks the core was made of:

August W. Domel Jr.
Firm: Domel, August W. Jr.
Address: P.O. Box 981
Dundee, IL 60118-0481
Phone: (630) 213-7800

 

[delphi_ote]

Anyone want the ? Maybe we could try to get this discussion focused a bit?

(For those not in the know, the are like the conch in Lord of the Flies. Whoever has them gets to ask one question or bring up one issue, and we all pursue it until we reach a conclusion. They are currently up for grabs, so do let me know.)

 

[Christophera]

Ok, so why do you continually post about the non-existence of a steel framed core? I didn't claim that there was no concrete in the core, but rather that your claim that there was no steel was ludicrous. And what's with the picture? What are you trying to prove with the picture?

Which picture?

This one of the concrete core of WTC 2

As for your link. Read in context, the report does not state that there were no steel columns at the core. Also, noting that the core carried "only gravity loads" would prove, quite to the contrary, that the concrete core you described was never used as a shear wall.

There is a great deal of confusion about the core because the plans were taken by the ex NYC mayor and hidden in his personal warehouse. Courts will not compell their return.

http://www.nyclu.org/g_archive020602.html

http://911research.wtc7.net/wtc/evidence/blueprints.html

http://www.didyouknow.org/terrorism.htm

Each of the WTC towers had a double-strength structure consisting of a concrete core supported by a steel structure around the outside.

Yet another group acknowledging the steel core. Why did you post that one?

As I said, the confusion caused by the missing blueprints MUST allow description that DO identify the concrete core.

And btw. Normally shear walls are as you say, not tapered. The WTC was very CUSTOM and optimized in every way for strength, 17 foot thick on the narrow axis at the base and 2 foot at the top.

 

[maccy]

To be honest, I'm amazed you guys keep trying to talk to this loon....

At the moment I'm quite interested in this attempt to go through things point by point, methodically. I'll probably be out of here again soon, I shouild think.

 

[maccy]

Anyone want the ? Maybe we could try to get this discussion focused a bit?

(For those not in the know, the are like the conch in Lord of the Flies. Whoever has them gets to ask one question or bring up one issue, and we all pursue it until we reach a conclusion. They are currently up for grabs, so do let me know.)

TheAlmond has requested them. I think a brief version of his question is:
why is the concrete core, as you describe it, several times stronger than it needs to be to support the tower?

I was just weighing with some background information about the document that Chris referenced in his reply to this question.

Edited to add:

this is TheAlmond's question post:

http://www.internationalskeptics.com/forums/showthread.php?postid=2109349#post2109349

 

[delphi_ote]

At the moment I'm quite interested in this attempt to go through things point by point, methodically. I'll probably be out of here again soon, I shouild think.

It's very interesting, but it's a bit like herding cats... very tempermental cats... on meth.

 

[Bell]

What is seen here is clearly the top and the roof slab of the core.

The core of the top of tower 2 falls on WTC 3​

You are 100% wrong!

The top of the south tower fell to the east...

 

[maccy]

It's very interesting, but it's a bit like herding cats... very tempermental cats... on meth.

It's easier than trying to persuade everybody to ignore chris though.

I'm hoping that we'll end up with a nice summary list of chris' points and how he can't back them up. Which people can post every now and again to save new people the trouble of getting embroiled in all this.

If anybody thinks Chris is gong to be persuaded to change his mind, I offer the following court transcript from one of his websiies as evidence that he won't:

http://algoxy.com/missingknowledge/220trans0.html

 

[Bell]

If anybody thinks Chris is gong to be persuaded to change his mind, I offer the following court transcript from one of his websiies as evidence that he won't:

http://algoxy.com/missingknowledge/220trans0.html

Yup, there's some crazy stuff in that transcipt!

 

[delphi_ote]

TheAlmond has requested them. I think a brief version of his question is:
why is the concrete core, as you describe it, several times stronger than it needs to be to support the tower?

Rock. Almond has the .

 

[The Almond]

Which picture?

This one of the concrete core of WTC 2

So you believe that there was a concrete core whose thickness was 17 feet which was supported by 3 inch thick steel rebar. Yes or no.

And btw. Normally shear walls are as you say, not tapered.

Source? My design experience has been that shear walls are never tapered. Argument for the special case.

The WTC was very CUSTOM and optimized in every way for strength, 17 foot thick on the narrow axis at the base and 2 foot at the top.

Ok, my analysis shows that 17 feet was way too thick, given the design loadings for the towers. If the building was optimized, they wouldn't have used a factor of safety of 5 for the structure thickness.

 

[delphi_ote]

I'm hoping that we'll end up with a nice summary list of chris' points and how he can't back them up. Which people can post every now and again to save new people the trouble of getting embroiled in all this.

That was exactly my hope as well. Or at least get to the bottom of some of the things he is talking about.

 

[Christophera]

So you believe that there was a concrete core whose thickness was 17 feet which was supported by 3 inch thick steel rebar. Yes or no.

Since annotation of that image I've recalled the foundation had 6 inch rebar. I am unsure of exactly where it changed but deniers have pointed out that the tightly coiled steel looks larger than 3 inch. I have to agree with this and so suspect there was an over lap, as that rebar in the base of the core wall appears larger than what I know continued to the top.

Source? My design experience has been that shear walls are never tapered. Argument for the special case.

Have you ever seen a 1300 foot wall? I know if I was designing one I would taper it.

Ok, my analysis shows that 17 feet was way too thick, given the design loadings for the towers. If the building was optimized, they wouldn't have used a factor of safety of 5 for the structure thickness.

Considering the liability I would specify designs to the absolute maximum strength. There are occasional hurricane force winds there.

The 1990 documentary detailed Yamasakis testing of core designs and the steel core version that Robertson had proposed began to fail as a model at 75 MPH wind speed.

The final call lies with the fact that not one single image from the demolition shows one of the supposed 1,300 foot steel core columns at an elevation over the ground. However, what I know to have existed is shown.

Here is a segment of concrete shear wall holding up the spire which is an interior box column located outside the core area and fastened to the concrete shear wall.

 

[Christophera]

Yup, there's some crazy stuff in that transcipt!

You are bascially trying to say that we know everything about the mind.

This site actually touches on the realities of what is possible.

http://www.hypnos.co.uk/hypnomag/peltbook/chapter4p4.htm

 

[The Almond]

Since annotation of that image I've recalled the foundation had 6 inch rebar.

Once again, rebar goes from #3 to #18 in size, with #18 being 2.257 inches in diameter and 4 inches in cross-sectional area. There's no such thing as a 6 inch diameter piece of rebar. And why, if you've now recalled the truth, do you still post that image as late as today? Does it take pages worth of mathematics to convince you to check your own work and assumptions? Why?

I am unsure of exactly where it changed but deniers have pointed out that the tightly coiled steel looks larger than 3 inch.

Since you're uninterested in mathematics, I won't bother proving that "tightly coiling" steel that's 3 inches thick would remove most of its structural integrity. Just say the word, however, and I'll produce the mathematics.

I have to agree with this and so suspect there was an over lap, as that rebar in the base of the core wall appears larger than what I know continued to the top.

You suspect something that you know from your analysis of some fuzzy pictures? Why not find some pictures of the overlap?

Have you ever seen a 1300 foot wall?

Yep, one was on the outside of the WTC towers.

I know if I was designing one I would taper it.

What? If you were designing one? Is this that common sense coming through, or are you actually using your years of acquired design experience and degree in civil engineering?

Considering the liability I would specify designs to the absolute maximum strength. There are occasional hurricane force winds there.

What hurricanes produce 1000 mile per hour winds? What hurricanes produce sustained winds over 300 miles per hour? I'll remind you that a category 5 hurricane produces winds above 156 miles per hour, and that only 3 have hit the US in the 20th century, none in New York.

The 1990 documentary detailed Yamasakis testing of core designs and the steel core version that Robertson had proposed began to fail as a model at 75 MPH wind speed.

This statement disproves your thesis. If Yamasakis were testing for 75mph winds, the shear forces on the building would have been nowhere near large enough to require a 17 foot thick shear wall.

The final call lies with the fact that not one single image from the demolition shows one of the supposed 1,300 foot steel core columns at an elevation over the ground.

So you want an image of a 1300 foot long steel column?

Here is a segment of concrete shear wall holding up the spire which is an interior box column located outside the core area and fastened to the concrete shear wall.

How thick is that shear wall? What is the size of the reinforcing steel and how far apart is it placed?