The Progressive Collapse Challenge

More relevant information:

www.nist.gov...

He summarized the findings for each area of analysis. The original design wind loads on the towers exceeded those established by the New York City Building Code and were higher than those required by other selected building codes of the era. Estimated wind loads vary by as much as 40 percent between two wind tunnel/climatological studies conducted in 2002 by CPP and RWDI as part of insurance litigation.

Dr. Sadek stated that the Demand/Capacity ratios estimated from the original design case are, in general, close to those obtained from a lower bound state-of-the-practice case. For both loading cases, a small fraction of structural components had Demand/Capacity ratios larger than 1.0; the safety of the WTC towers was most likely not affected by this.

He noted relevant issues for future investigation including (1) availability of standards for conducting wind tunnel tests and for methods to estimate wind effects from test results for design purposes, (2) availability of protocols for selection of site-specific wind speed and directionality, and (3) adequacy of prescriptive wind load standards for very tall buildings.

Q: How is capacity defined? [referring to the Demand/Capacity ratios for the structural component estimates].
A: Capacity is defined by using the American Institute of Steel Construction (AISC) Allowable Stress Design procedure.

.....


Dr. McGrattan presented the results of fire simulations of WTC 1 and WTC 2 performed with the NIST Fire Dynamics Simulator (FDS). He explained the major trends in fire movement and temperature on the various floors, and how these trends were validated by visual observations. He discussed the sensitivity analysis performed to determine how the results of the calculations changed as a consequence of varying the major input parameters. It was concluded that the fires in WTC 1, which could generally be characterized as oxygen-limited or ventilation-controlled, were less sensitive to changes in the fuel and combustible loadings, compared to the fires in WTC 2, which could be characterized as fuel-limited or fuel-controlled.

www.ldeo.columbia.edu...

^ Direct columbia.edu link to seismograph data summary.



per wtc.nist.gov...

there have been 31 fires combined between WTC 1 and 2 between 1973 and 1999. why didn't any of those fires bring down the towers?

Finding (1):
Water supply capacity and redundancy met or exceeded best practices.
Finding (2): Water supplies to the automatic sprinklers and
standpipe systems exceeded minimum requirements for highrise
office occupancy protection in accordance with NFPA 13.
Finding (3): Generally, sprinkler risers provided single points of
supply at each floor level,which causes the potential for single point failures.
Finding (4): In specific cases, the
lack of interconnections for adjacent standpipe zones resulted
in the potential for single point failures of the standpipe systems.

Both towers 1 and 2, had 2 seperate sprinkler systems. one on the west end, one on the east. Aprox 30,000 gallons of water was in reserve.

15000 gallons on the roof (near it at least)

5000 gallons on floor 70

5000 gallons on floor 42

5000 gallons on floor 19

The smoke management systems in WTC 1 and WTC 2, which
provided the capability for a manual smoke purge within an
individual HVAC zone on a quadrant-by-quadrant basis, were
not initiated on September 11, 2001.

although he says, the system probably wouldnt have worked.. Why didnt they at least try?

Wow, i was calling for an independent investigation... this is everything i could have ever hoped for.. and from nist.gov.. oh my god!

[edit on 28-8-2005 by senseless04]

[edit on 28-8-2005 by senseless04]

Originally posted by bsbray11
Similarly there is no evidence that the fires "got up to temperature" much beyond 800 degrees at any given time, for any length of time. More likely they hovered around 600 degrees for the majority of the time, until they started dying, etc.

Not even "for the majority of the time". Here is what NIST, the very government body tasked with whitewashing the affair, said:

=====================================================
NIST Report NCSTAR 1-3: Mechanical and Metallurgical Analysis of Structural Steel

E.3.6 Fire Exposure and Temperatures Reached by the Steel - p43

Only three locations had evidence that the steel reached temperatures above 250 °C.
These areas were:
• WTC 1, east face, floor 98, column 210, inner web,
• WTC 1, east face, floor 92, column 236, inner web,
• WTC 1, north face, floor 98, column 143, floor truss connector
Other forensic evidence indicates that the last example probably occurred in the debris pile after collapse.


6.6.3 Metallographic Analysis of Elements Exposed to Fire - p147

Finally, in the several [exterior] columns with known pre-collapse fire exposure, metallographic analysis provided no conclusive evidence that the steel exceeded 625 °C, based on calibrations in furnace exposure studies of WTC steel reported in NIST NCSTAR 1-3E.


6.8.5 Fire Exposure of Exterior Panel Sections - p149

Based on microstructural analysis of the recovered structural steel, there was no evidence indicating that the pre-collapse fires were severe enough to affect the steel microstructure of these pieces. Based upon this evidence, it is believed that no steel was recovered which experienced temperature excursions above 600 °C for any significant length of time as a result of the pre-collapse fires.


6.8.6 Fire Exposure of Core Columns - p149

Two of the core columns with as-built locations in the fire-affected floors were examined for paint cracking. The few areas with sufficient paint for analysis did not show mud cracking patterns, indicating the columns did not exceed 250 °C. (It must be recognized that the examined locations represent less than one percent of the core columns located in the fire-exposed region, and thus these temperatures cannot be considered representative of general conditions in the core).
=====================================================

[edit on 2005-8-28 by wecomeinpeace]

Geez, apparently I was really being conservative with my figures.

Thanks for pointing that out man.

To vindicate Kevin Ryan, i would also like to point out that the person to whom he sent the letter shortly after 9/11 was Frank Gale.

Frank Gale is one of the NIST PHDs responsible for doing the above mentioned tests, and computer simulations. These tests, prove that the information within the letter sent to gale was completely factually accurate, and that there was no basis for his removal from UL. His termination was completely unjust.


[edit on 28-8-2005 by senseless04]

Originally posted by wecomeinpeace

Originally posted by QuietSoul
Anyhow, I'm gonna shoot this guy an email back.. any questions you want me to ask?

One more question for this guy:

If you were contracted to demolish the WTC towers but had to make it look like it collapsed by itself from the top down, how would you do it?

[edit on 2005-8-27 by wecomeinpeace]

There's a quote going around from the head of Controlled Demolition which was made soon after the WTC collapse in which he said to bring down those towers he would of had a big detonation at the core base and cutting explosions on the levels so the weight of the building would bring itself down once it's foundation was compromised.

The squibs would only be a part of it anyway. The molten steel (or aluminium as Howard assumes) at the cores base, days afterwards are the suggestion of a mini-nuke or thermite explosion, along with the sizemic recordings and other suggestive evidence.

Don't forget that aspect of the demolition either.

Also, would it be a far-fetched cry to assume the US government/CIA etc would have access to explosive technology that a demolition company might not? Considering NASA are responsable for developing the industry standard steel cutting explosive, who really can say they or someone else has developed something that's yet to reach a public market. Considering the US has the biggest miltary budget and 9/11 was cause for more wars, explosive technology could of been well into new areas of research by that date.

It's possible that the people who would know about how a building gets demolished wouldn't neccessarily be using the same stuff. The US airforce/Military have a lot of tech which others don't and in some cases are 20 years ahead in research and testing than what is made public knowledge and even what is being used in the airforce.

If this is a conspiracy, there's cause to believe they would be using the best of the best rather than what a demolition company may use everyday.
Maybe in 10 years there will be some 'new' fandangle demolition charges which turns out, were first publically used on 9/11?

‘If I were to bring the towers down, I would put explosives in the basement to get the weight of the building to help collapse the structure,’ [says] Mark Loizeaux, president of Controlled Demolition, Inc.


Link




[edit on 28-8-2005 by senseless04]

[edit on 28-8-2005 by senseless04]

First, Kevin Ryan had no right to send that letter. It doesn't matter if it was to President Bush. He was not a spokesperson for UL in any way, and wasn't even in the fire division of the company. Why is that so hard to understand? If you send a letter speaking for your company, and you aren't in a position to do so, YOU WILL BE FIRED. Plain and simple. Try it sometime and see what happens.

Secondly, if they cut the foundation of the building, you're gonna see the building fall like a demolition, where the bottom of the building moves, and then comes down. That didn't happen with the WTC. It fell from the top down, with no evidence of the foundation being cut.

[edit on 29-8-2005 by Zaphod58]

Originally posted by Zaphod58
First, Kevin Ryan had no right to send that letter. He was not a spokesperson for UL in any way, and wasn't even in the fire division of the company. Why is that so hard to understand? If you send a letter speaking for your company, and you aren't in a position to do so, YOU WILL BE FIRED. Plain and simple. Try it sometime and see what happens.

Secondly, if they cut the foundation of the building, you're gonna see the building fall like a demolition, where the bottom of the building moves, and then comes down. That didn't happen with the WTC. It fell from the top down, with no evidence of the foundation being cut.

It appeared to me as if he was sending a letter to a friend, expressing his own concern. He even said "this fact should be a grave concern to my company" not "this is a grave concern to my company"

a 2.1 and 2.3 earthquake is not evidence of that? 80,000lbs of ammonium nitrate at the local rock quarry (near CU seismograph facility) which has daily blasts register a 1-2 magnitude earthquake. 40tons of explosives which are burried in the ground (firm coupling with the earth)! I would think that these blasts would create a stronger force than the falling of the twin towers.

What about tower 7? Perfect demolition. They didnt have any pesky corporate offices to deal with i guess. It'd be easier to move around an all government building.

plus, towers 1 and 2 were 110 stories, theres no way something that big and skinny could fall 1100 feet and not spread out over a small area. The wind resistance alone while falling would cause the debris to drift. Plus, the aformentioned nist publications say that there was a 25% wind resistance on 9/11. Meaning there wasnt a lot of wind, but there was wind which would have had a bearing, regardless of how minute.



[edit on 29-8-2005 by senseless04]

He sent that letter to the head of NIST, and about 12 conspiracy websites (okay I don't know the exact number, but it was quite a few websites.)

The head of the place that had the "seismic" readings came out and stated that there was NO EVIDENCE of seismic evidence from the collapse, and explained what the readings were, but I'm too lazy to look it up right now.

There WAS quite a bit of debris spread from towers 1 and 2 over a good sized area, but a large portion of it ended up in the footprint of the building.

[edit on 29-8-2005 by Zaphod58]

Originally posted by Zaphod58
He sent that letter to the head of NIST, and about 12 conspiracy websites (okay I don't know the exact number, but it was quite a few websites.)

The head of the place that had the "seismic" readings came out and stated that there was NO EVIDENCE of seismic evidence from the collapse, and explained what the readings were, but I'm too lazy to look it up right now.

He sent that letter to Frank Gale, which conducted his own experiments with the support of the NIST. The conclusions went 100% against the official story. He also carbon copied the letter to another friend of his whom also had evidence to go against the official story. After he was canned he gave authorization for copies of the letter to be placed on conspiracy theory websites.

If you had read the above mentioned links you would know this. You dont have to look it up, i already provided it. Just read it.

If you look at the seismic readings that i posted directly from columbia's (columbia university, ran the seismic center that detected the blasts. this is the word straight from the source.) website you'll notice a HUGE initial burst of energy. Regardless of what this was, it was never explained in the official story.

Infact, the official story says "there was not major ground shaking". Maybe if you live in california, where 2.1's are every day. But not in new york.

www.nist.gov...

ALL the reports given on this 2 day wtc analysis period go against the official story.


[edit on 29-8-2005 by senseless04]

Originally posted by TheShroudofMemphis

There's a quote going around from the head of Controlled Demolition which was made soon after the WTC collapse in which he said to bring down those towers he would of had a big detonation at the core base and cutting explosions on the levels so the weight of the building would bring itself down once it's foundation was compromised.

The squibs would only be a part of it anyway. The molten steel (or aluminium as Howard assumes) at the cores base, days afterwards are the suggestion of a mini-nuke or thermite explosion, along with the sizemic recordings and other suggestive evidence.

Ah! And suddenly I understand why thermite would've been used at the base. This is what I was wondering earlier, when it was first brought up in Howard's thread.

Also, would it be a far-fetched cry to assume the US government/CIA etc would have access to explosive technology that a demolition company might not? Considering NASA are responsable for developing the industry standard steel cutting explosive, who really can say they or someone else has developed something that's yet to reach a public market. Considering the US has the biggest miltary budget and 9/11 was cause for more wars, explosive technology could of been well into new areas of research by that date.

It's possible that the people who would know about how a building gets demolished wouldn't neccessarily be using the same stuff. The US airforce/Military have a lot of tech which others don't and in some cases are 20 years ahead in research and testing than what is made public knowledge and even what is being used in the airforce.

If this is a conspiracy, there's cause to believe they would be using the best of the best rather than what a demolition company may use everyday.
Maybe in 10 years there will be some 'new' fandangle demolition charges which turns out, were first publically used on 9/11?

Exactly. There's no questioning that if this was a conspiracy (and according to WCIP's research, a great majority of those here believe it was), the option of contracting new technology to demolish those buildings would certainly be there. Unconventional demolition. You wouldn't call up the local demolition team; you would call up your top henchmen and contract a conspiracy.

Originally posted by Zaphod58
There WAS quite a bit of debris spread from towers 1 and 2 over a good sized area, but a large portion of it ended up in the footprint of the building.

That's not true at all. 80+% of the debris was blasted outside the footprints, some of it landing up to 600 feet away. And the satellite pics visually confirm this.

Originally posted by bsbray11


Exactly. There's no questioning that if this was a conspiracy (and according to WCIP's research, a great majority of those here believe it was)

An informal poll is hardly research.

You are reffering to this right?

www.abovetopsecret.com...

Seventy people is not a majority on a site with thousands of members.

Originally posted by LeftBehind
Seventy people is not a majority on a site with thousands of members.

Seventy people is apparently the majority of members that visit the 9/11 section of ATS.

Originally posted by wecomeinpeace

Originally posted by Zaphod58
There WAS quite a bit of debris spread from towers 1 and 2 over a good sized area, but a large portion of it ended up in the footprint of the building.

That's not true at all. 80+% of the debris was blasted outside the footprints, some of it landing up to 600 feet away. And the satellite pics visually confirm this.

There were though many huge chunks of exterior colums, and a big pile of pulverized concrete that fell directly in on itself. Dont forget, there were 7 sub basements. According to the president of CDI, if he were blowing up the WTC he wouldve blown them out at the base, under the 7 sub basements. So they too would collapse, leaving an 84 foot void to be filled in by raining debris. In theory at least, assuming that speculations about the attacks are correct. My calculations are that at a rate of 5MPH wind force, the debris would move horizontally at a rate of 7 feet per second, during the 10 second fall a total displacement of 70 feet could occur. The wind force, was actually much higher, upwards of 15MPH (220foot horizontal displacement). But still doesnt even come close to explaining debris being 600 feet away. This does assume of course, that the demolition was perfectly symmetrical.


[edit on 29-8-2005 by senseless04]

Originally posted by senseless04
But still doesnt even come close to explaining debris being 600 feet away. This does assume of course, that the demolition was perfectly symmetrical.

I did some calculations a while back which showed that an object, in accordance with ballistic trajectory, would have to be ejected at a speed of 9.99m/s to land 250 feet away from a tower, generously assuming the beam came from the top-most collapse point. A single, 12-foot section of exterior column weighs 400Kg. This requires 399,6000kgm/s^2 of energy to create such an impulse, and that's not counting the energy sink of snapping the originally 36' long beam and removing it from its welds and bolts in the first place.

KABOOMIES!!



Later, however, I discovered the following, but didn't bother posting it since my point had been made and gone unrefuted:



This is an exterior panel, largely intact, which landed in the roof of the Winter Garden, between the American Express Building and the Merryl Lynch Building. As you can see, it has two and two-thirds 36-foot beams in it, and three spandrel plates. That means the thing weighs somewhere close to 3500Kg, and it ended up more than 500 feet away from WTC1.



The amount of energy required to do this is enourmous. I'm too lazy to calculate it now, unless someone is curious.

The wind force, was actually much higher, upwards of 15MPH...

If you have the time, we can exchange info via U2U so that you can double-check my previous calculations. At the time, I observed that air resistance would play a significant role in reducing or increasing (in the case of a "tail wind") the lateral ejection distance of the beams and covers thus increasing or decreasing the energy needed to provide the impulse to reach that distance, but I was subsequently called an idiot by the debunking crowd for such a suggestion... *shrug*

I'm of the opinion that the demolition theory is supported both by the high-energy ejection of debris, AND by the symmetry of the collapses. When people point to the "collapsed into its own footprint" factor as supporting the demo theory, I think they mean the symmetry of the collapses. With gravity-driven collapse of a structure that is weakened and "bowing" to one side, one would expect the top section to topple over sideways, i.e. asymmetrical collapse. However if the pancake theory were true, one would expect the lower section to collapse into its own footprint, rather than being blasted all over Manhattan. Thus the observed phenomena are completely incongruous with the gravity-driven collapse zipper/pancake theory.

[edit on 2005-8-29 by wecomeinpeace]

i thought i may have been able to justify it by saying "ah it was light debris". But that is a HUGE chunk of the towers. After re-watching the collapse portions of the video, it looks like the towers bent outward. Kind of like if you were to peel a banana. But still doesnt explain the debris up to 600'.

The wind was obviously blowing to the south east. That huge chunk of building landed to the west. The more i look into it, it doesnt make any sense. The more it looks as if the building just blew up. Someone, a few posts ago brought up the idea of a mini-nuke. Would the parking garage of the WTC towers be able to withstand this kind of pressure? If so, would it have caused the gaping hole in wtc 6? There is still an unknown factor to us. We won't be able to explaint he collapse until we can figure out, 1) what kind of explosives were used, 2) if the demo was exactly symetrical.

Other than that 1 huge piece (which is the top of the building by the way), all other pieces fall within the exceptable perimeter established above (220 feet maximum drift to E/SE) with a 20' foot perimeter around the base of the tower receiving most of the debris.




[edit on 29-8-2005 by senseless04]

[edit on 29-8-2005 by senseless04]

[edit on 29-8-2005 by senseless04]

Originally posted by senseless04
Dr. Sadek stated that the Demand/Capacity ratios estimated from the
original design case
are, in general, close to those obtained from a lower bound state-of-the-practice case. For both loading cases, a small fraction of structural components had Demand/Capacity ratios larger than 1.0; the safety of the WTC towers was most likely not affected by this.

You do realize that he is talking about the original design, and not about the stability of the structure post impact, or do you?

The key thing to understand here is that although the building had a decent reserve capacity built into it, it was not “%600” or some other absurd number that is commonly claimed.

In addition, the aircraft impact took out a fairly significant number of the columns thus increasing the demand on the undamaged columns.

If the heat from the fires caused some of the columns to loose any of their capacity, then those loads would be transferred to still other columns. This would be especially critical in the core area where each of the columns bore a significantly larger portion of the building loads then the individual exterior columns.

If the heat of the fires caused the floor trusses to sag, this would cause the vertical forces applied by the trusses to the exterior columns to become horizontal, inward forces. These forces would then cause the exterior walls to buckle inward, regardless of their temperature.

Once the exterior columns started to buckle, their ability to support the loads on them dropped considerably.

Originally posted by senseless04
If you look at the seismic readings that i posted directly from columbia's (columbia university, ran the seismic center that detected the blasts. this is the word straight from the source.) website you'll notice a HUGE initial burst of energy. Regardless of what this was, it was never explained in the official story.

What “HUGE initial burst of energy?”



The spikes in the red box were caoused by the impact of the building with the ground. They are the same as the data in the box from the detailed graph below:



Where is this “HUGE initial burst of energy?”

From the people that recorded the seismic data:

Notice the seismic signals from the first impact at 08:46 EDT, second impact at 09:03 (very small), two large signals due to collapse of the World Trade Center buildings at 09:59 and 10:28 (EDT).


”Collapses of the two WTC towers generated large seismic waves, observed in five states and up to 428 km away. The North Tower collapse was the largest seismic source and had local magnitude ML 2.3.“

"There is no scientific basis for the conclusion that explosions brought down the towers," Lerner-Lam tells PM. "That representation of our work is categorically incorrect and not in context."

Originally posted by HowardRoark
In addition, the aircraft impact took out a fairly significant number of the columns thus increasing the demand on the undamaged columns.

About 3-10 of the 47 columns is fairly significant to you ?
Don't try and twist the facts.