I will abandon CD hypothesis if...

[CptColumbo]

My personal recommendation would be to read up on publicly available papers on architectural and engineering topics, not saying you should learn it like a religion but I think it'll benefit you just to look into the subjects on your free time when you're board.

I've been taking architecture courses since my high school years (which is not so long ago) so I've kind of learned the subject as I went and I used what I learned to understand the dynamics of the collapses. For me NIST served more as a confirmation of my observations, it gave me the ability to look at what they collected for analyzation, so I could determined if what I saw was consistent with the material I read. If you want and if I have time perhaps I can scan and PDF some excerpts from some of my text books, if you'd like to read in on specific subjects. I'm pretty sure that there's not much on my books that you won't find here but nevertheless...

It has been my experience, that when a member of the TM mentions the books on the subject that they have read, there is never a text book on engineering or architecture. They seem to believe that quantity makes up for quality. GB is right that you don't have to get a degree in any of the disciplines, but you might want to suplement what you are reading on the internet with books that will help you understand the subject better.

 

[Grizzly Bear]

It has been my experience, that when a member of the TM mentions the books on the subject that they have read, there is never a text book on engineering or architecture. They seem to believe that quantity makes up for quality. GB is right that you don't have to get a degree in any of the disciplines, but you might want to suplement what you are reading on the internet with books that will help you understand the subject better.

I've been using "Understanding Structures" by Fuller Moore, and Fundamentals of Building construction fourth Edition by Edward Allen and Joseph Iano for some of my more recent references in posts. Both are great reading material on a number of concepts dealing with this...

The former has a lot of detailed sketches and fundamentals which are easy to understand and read up on. The latter deals with construction methods in greater detail as well has having good pictures demonstrating column design and overall construction.

 

[Bluesky]

I will abandon CD hypothesis if....

In other words, if the "new phenomenon" put forth by NIST, which was responsible for the collapse of WTC7, is accepted by the engineering community and changes are made to building practices and codes to keep any other sky scrapper from falling, I will abandon the CD hypothesis and accept that all 3 WTC buildings collapses for reasons stated by NIST.[/QUOTE]

Since steel high rise buildings were first erected, in the 1910's, engineers have thought that the way to protect them from failure in a fire was to cover them in fire protection to stop the steel reaching a temperature where the steel started to reduce strength. In the last 10 years engineers have realized that the effects of thermal expansion are much more onerous than the effects of strength reduction.

NIST are essentially recommending that engineers should start explicitly modelling the effects of thermal expansion. Organizations such as the Council on Tall Buildings and Urban Habitat have just published their report which seems to agree with NIST.

So the process is changing. Welcome to the real world.

 

[A W Smith]

In other words, if the "new phenomenon" put forth by NIST, which was responsible for the collapse of WTC7, is accepted by the engineering community and changes are made to building practices and codes to keep any other sky scrapper from falling, I will abandon the CD hypothesis and accept that all 3 WTC buildings collapses for reasons stated by NIST.

Since steel high rise buildings were first erected, in the 1910's, engineers have thought that the way to protect them from failure in a fire was to cover them in fire protection to stop the steel reaching a temperature where the steel started to reduce strength. In the last 10 years engineers have realized that the effects of thermal expansion are much more onerous than the effects of strength reduction.

NIST are essentially recommending that engineers should start explicitly modelling the effects of thermal expansion. Organizations such as the Council on Tall Buildings and Urban Habitat have just published their report which seems to agree with NIST.

So the process is changing. Welcome to the real world.

http://www.ctbuh.org/

from
CTBUH Response to NIST WTC7 Report

The Council would like to make it clear that it sees no credibility whatsoever in
the 911 ‘truth movement’ and we believe, with the vast majority of tall building
professionals, that all the failures at the WTC (WTC 1, 2, 5, 6 and 7) were a
direct or indirect result of the planes that were flown into the two towers. We
have carefully looked at the evidence that the 911 ‘truth movement’ presents
and we cannot see any credible scientific evidence of a controlled demolition
on WTC 7 or any of the other WTC buildings. The Council considers that the
‘truth movement’ is a distraction and should not obfuscate the performance
issues which should be at the center of the debate about how best to continue​

to improve and develop fire and life safety in tall buildings.

 

[Sizzler]

http://www.ctbuh.org/

from
CTBUH Response to NIST WTC7 Report

Let's keep this in context.

The paragraph directly before what you quoted.

The Council does not agree with the NIST statement that the failure was a
result of the buckling of Column 79. We believe that the failure was a result of the collapse of the floor structure that led to loss of lateral restraint and
subsequent buckling of internal columns.

Anyway. All of this is way too complicated for me to understand. Just thought I would add context to the quote you added.

Cheers.

 

[Dave Rogers]

Let's keep this in context.

The paragraph directly before what you quoted.

The Council does not agree with the NIST statement that the failure was a
result of the buckling of Column 79. We believe that the failure was a result of the collapse of the floor structure that led to loss of lateral restraint and
subsequent buckling of internal columns.

That's a very odd statement. The Council is actually contradicting its first sentence with its second, and the second statement is a better summary of NIST's findings than the first. To give an analogy, it's like saying, "We don't agree that the victim was killed by a bullet passing through his brain. We believe he was killed by a shot fired from the defendant's revolver that passed through his head and caused serious brain damage." They seem simply to be taking two different points in a chain of causality, claiming that NIST has defined one of them to be the cause, then arguing that the other is really the cause. In effect, they seem to be trying to make it look like they disagree with NIST while not being able to find grounds for doing so. Is this something to do with wanting to challenge revised building codes on cost grounds?

Dave

 

[Bluesky]

That's a very odd statement. The Council is actually contradicting its first sentence with its second, and the second statement is a better summary of NIST's findings than the first. To give an analogy, it's like saying, "We don't agree that the victim was killed by a bullet passing through his brain. We believe he was killed by a shot fired from the defendant's revolver that passed through his head and caused serious brain damage." They seem simply to be taking two different points in a chain of causality, claiming that NIST has defined one of them to be the cause, then arguing that the other is really the cause. In effect, they seem to be trying to make it look like they disagree with NIST while not being able to find grounds for doing so. Is this something to do with wanting to challenge revised building codes on cost grounds?

Dave

The CTBUH clarifies this point in their conclusions.

"The Council does not agree with the NIST statement that the failure was a
result of the buckling of Column 79. We believe that the failure was a result of the collapse of the floor structure that led to loss of lateral restraint and then buckling of internal columns. This is an important distinction, as NIST appears to be seeking improved performance from floors rather than columns."

Certainly I agree that this disagreement is nothing like the disagreement between the fire causing the collapse and CD causing the collapse. However I think what the Council are saying is that it is important to discuss the collapses at this level of detail and the whole CD theory is a dis-service to the industry and is a distraction that stops them getting into this level of detail.

 

[PhantomWolf]

That's a very odd statement. The Council is actually contradicting its first sentence with its second, and the second statement is a better summary of NIST's findings than the first. To give an analogy, it's like saying, "We don't agree that the victim was killed by a bullet passing through his brain. We believe he was killed by a shot fired from the defendant's revolver that passed through his head and caused serious brain damage." They seem simply to be taking two different points in a chain of causality, claiming that NIST has defined one of them to be the cause, then arguing that the other is really the cause. In effect, they seem to be trying to make it look like they disagree with NIST while not being able to find grounds for doing so. Is this something to do with wanting to challenge revised building codes on cost grounds?

Dave

I think that it's more a case of quibbling over the details. NIST says they think that heat expansion broke the supporting trusses and buckled the column, the CTUBH are saying that several floors collapsed (something quite common in skyscrapper fires around the world) and without their support the column buckled. It's like two doctors agruing if the patient's heart attack was caused by his love of hamburgers or his two pack a day smoking habit. While Doctor 2 disagrees with the "Hamburgers killed him" theory, they also think they crowd claiming that the guy was shot are total wackos.

 

[Dave Rogers]

The CTBUH clarifies this point in their conclusions.

"The Council does not agree with the NIST statement that the failure was a
result of the buckling of Column 79. We believe that the failure was a result of the collapse of the floor structure that led to loss of lateral restraint and then buckling of internal columns. This is an important distinction, as NIST appears to be seeking improved performance from floors rather than columns."

That still doesn't make sense. If CTBUH believes that the collapse was caused by the floors collapsing but NIST doesn't, then how come NIST is seeking improved performance from floors rather than columns? Is there a misprint in there somewhere?

I realise this has very little to do with conspiracy theories by now, as it's abundantly clear to anyone without a preconceived opinion that the CTBUH fully accepts the broader conclusion that WTC7 collapsed due to a contents fire, and that building codes should at least be reviewed and reconsidered in the light of this conclusion.

Dave