29 Structural & Civil Engineers Cite Evidence for Controlled Explosive Demolition

[Newtons Bit]

You sure you din't mean to write "just the other side of impossible" instead of "Next to impossible"?

Give me an unlimited design budget and construction budget and I can do anything. Just don't get surprised about the cost of my skyhooks...

 

[Architect]

Actually there were. Recommendations for analysis of thermal expansion and new fire load cases were added to ASCE7 (which, to make a long story short, is a building code) early in the revision process for the 2010 publication of ASCE7. This was because of the WTC7 collapse.

I see I was beaten to it.

 

[ElMondoHummus]

Chris said what????

http://www.facilitiesnet.com/securi...m-NIST-World-Trade-Center-Investigation--9850

Future buildings—especially tall structures—should be increasingly resistant to fire, more easily evacuated in emergencies, and safer overall thanks to 23 major and far-reaching building and fire code changes approved recently by the International Code Council (ICC) based on recommendations from the Commerce Department's National Institute of Standards and Technology (NIST).

Among the accepted changes:

• Greater reliability of sprinklers with a minimum of two water supply risers for each sprinkler zone in buildings more than 420 feet high. Each riser is required to supply sprinklers on alternate floors and will be placed in remotely located stair enclosures.
• A one-hour increase in the fire-resistance rating of structural components and assemblies in buildings more than 420 feet high.
• Explicit adoption of the "structural frame" approach to fire resistance ratings that requires all members of the primary structural frame to have the higher fire resistance rating commonly required for columns. The primary structural frame includes the columns; other structural members including the girders, beams, trusses and spandrels having direct connections to the columns; and bracing members designed to carry gravity loads.
• Broadening the definition of the primary structural frame to include bracing members essential to vertical stability (such as floor systems or cross bracing) whether or not they carry gravity loads.
• Increasing bond strength for fireproofing to nearly three times greater than currently required for buildings 75-420 feet high and seven times greater for buildings more than 420 feet high.

... And among the propositions for future code upgrades:

• Requiring buildings more than 420 feet high to be designed to survive a building contents fire to burnout without more than local failure of the structural frame.
• Requiring structures not to suffer a collapse disproportionate to a local initiating failure caused by an accident or incident.

The engineers here can elaborate on how each of the above is drawn from the NIST report, but the fact of the matter is that it is completely wrong to claim that no code modifications relating to mitigating structural failures have been implemented.


------


ETA: Wait... Chris was singling out Building 7??

Actually there were. Recommendations for analysis of thermal expansion and new fire load cases were added to ASCE7 (which, to make a long story short, is a building code) early in the revision process for the 2010 publication of ASCE7. This was because of the WTC7 collapse.

There was a huge fight over it and it was finally removed from the last top-level committee meeting. It ultimately came down to money. Building owners aren't willing to pay the additional fee (I'm talking several million dollars for a building the size of WTC7) for such a rare occurrence. Building owners are willing to accept that their building will be lost in an event where water is shut off for an entire city for 12 hours AND firefighters stop fighting. It's kind of a no-brainer.

Revisions to, for example, the Eurocodes to introduce additional redundancy and help limit the risk of dispropportionate progressive collapse.

This has been dealt with before, in one of the (many) technical threads notable many by the absence of Truthers.

Good grief... The NIST report on the twin towers was released in what, 2005? It took until the 2008 ICC meeting before those were voted in. When was the NCSTAR1-A report released? And what year is it now?

Narrowing down the argument by asking about code changes from a report that was just recently released is dishonest. Let's see what happens in 2010 or '11. And in the meanwhile, let's all take note of how dishonest Chris is in his argument. This is why I have him on ignore.

 

[Architect]

Spectacular, isn't it? But hell, what would we trained professionals know about it. I should have just bunked off all those compulsory structures and fire engineering classes at University, eh?

 

[Christopher7]

WTC7 was beyond a "worse case scenario" pre 9/11

What made it a "worse case scenario"?

heres what a post 9/11 skyscraper looks like
designed by your pal and mine, Mr Les Robertson

Leslie does NOT say he changed his outrigger design, or made it stronger. He just added corner elevators and 'safe' floors.
I do not know of any structural changes recommended by NIST as a result of the collapse of WTC 7. Do you?

@ 2:40
"Robertson resigned the financial center, using some of the same innovative ideas he used to build the WTC, especially the outrigger trusses and modular design that helped stabilize his lighter, taller building design, while giving it extra strength."

 

[Newtons Bit]

Good grief... The NIST report on the twin towers was released in what, 2005? It took until the 2008 ICC meeting before those were voted in. When was the NCSTAR1-A report released? And what year is it now?

Narrowing down the argument by asking about code changes from a report that was just recently released is dishonest. Let's see what happens in 2010 or '11. And in the meanwhile, let's all take note of how dishonest Chris is in his argument. This is why I have him on ignore.

There's a very strict procedure for getting new things into codes. It takes years. A very large number of eyes are required to go over any new code provisions and make sure they're reasonable and legit. Proposed changes must also be submitted years before the next publication so that they have a chance to be reviewed.

The International Building Code (what most jurisdictions in the US use) are updated every 3 years (2000, 2003, 2006, 2009). I currently live in an area that just adopted the 2006 version.

ASCE 7, the engineers code for loads and applied forces (referenced in IBC) is updated less regularly: 2002, 2005, 2010.

Oh, and before a "truther" goes off, the building codes are produced by NON-GOVERNMENT ENTITIES. The architectural and engineering professions are self-regulating. Which is one of the reasons why we call ourselves professionals.

 

[Christopher7]

Spectacular, isn't it? But hell, what would we trained professionals know about it. I should have just bunked off all those compulsory structures and fire engineering classes at University, eh?

"we trained professionals"?

The 29 trained professionals gave their names and credentials.

A bunch of anonymous, ill mannered adolescents are claiming to be experts.

Your "professional status" doesn't mean diddly squat outside a small circle of friends.

You do have a flair for the ironic. You demand structural engineers because architects are not qualified to understand the structural details and then claim to know more about structure than they do.

 

[ElMondoHummus]

Spectacular, isn't it? But hell, what would we trained professionals know about it. I should have just bunked off all those compulsory structures and fire engineering classes at University, eh?

Yeah, it is spectacular... sort of in the same way that the Hindenberg was spectacular in regards to transportation safety .

The sad thing is, I'm not a trained professional in this field like you are. The hard science part of my schooling was in chemistry and biology. The topics of my education (bio chem, organic chem, etc.) are so micro compared to the extreme macro nature of tall structures that I couldn't be any further out of my field without actually having had taken a different major in college. Yet, I'm able to comprehend this issue and the surrounding context better than truthers can in this forum. I think it's because I try my best to be is an honest researcher in regards to these things, unlike other posters here.

Sometimes, the deliberate obliteration of honesty I see among conspiracy peddlers is disheartening. I have to keep reminding myself that their level of intellectual ability is not indicative of society's in general so I can feel better about life.

 

[Jackanory]

"

The 29 trained professionals gave their names and credentials.

A bunch of anonymous, ill mannered adolescents are claiming to be experts.

Your "professional status" doesn't mean diddly squat outside a small circle of friends.

You do have a flair for the ironic. You demand structural engineers because architects are not qualified to understand the structural details and then claim to know more about structure than they do.

Then why are you here? Go forth Christopher and do something about it instead of boring us with you superior knowledge.

 

[Christopher7]

There's a very strict procedure for getting new things into codes. It takes years. A very large number of eyes are required to go over any new code provisions and make sure they're reasonable and legit. Proposed changes must also be submitted years before the next publication so that they have a chance to be reviewed.
The International Building Code (what most jurisdictions in the US use) are updated every 3 years (2000, 2003, 2006, 2009). I currently live in an area that just adopted the 2006 version.
ASCE 7, the engineers code for loads and applied forces (referenced in IBC) is updated less regularly: 2002, 2005, 2010.

What structural changes did NIST recommend to prevent the total collapse of outrigger truss buildings?

 

[rwguinn]

Give me an unlimited design budget and construction budget and I can do anything. Just don't get surprised about the cost of my skyhooks...

I keep mine out with the Rigidium. Inventory taxes are a killer! good thing they're invisible.

 

[Christopher7]

Then why are you here? Go forth Christopher and do something about it instead of boring us with you superior knowledge.

Fear thee not. I shall go forth and spread the truth. But I feel compelled, from time to time, to 'bore' you with the facts.

 

[Grizzly Bear]

Spectacular, isn't it? But hell, what would we trained professionals know about it. I should have just bunked off all those compulsory structures and fire engineering classes at University, eh?

Yup... according to C7 those are worthless. Danged University required courses!

 

[twinstead]

"we trained professionals"?

The 29 trained professionals gave their names and credentials.

A bunch of anonymous, ill mannered adolescents are claiming to be experts.

Your "professional status" doesn't mean diddly squat outside a small circle of friends.

You do have a flair for the ironic. You demand structural engineers because architects are not qualified to understand the structural details and then claim to know more about structure than they do.

And your "29 trained professionals" claiming they know more than the authors of the reports and the experts who contributed don't mean diddly squat outside a small circle of paranoid malcontents spewing gibberish on obscure internet forums.

Again. DO SOMETHING ABOUT IT, because your arrogant little internet cult is being really annoying.

 

[Christopher7]

what would we trained professionals know about it. I should have just bunked off all those compulsory structures and fire engineering classes at University,

Yup... according to C7 those are worthless.

Worthless are claims of expertise made by anonymous posters.

You brought up an interesting point. Architects must take courses in structure and fire engineering.

 

[ElMondoHummus]

And your "29 trained professionals" claiming they know more than the authors of the reports and the experts who contributed don't mean diddly squat outside a small circle of paranoid malcontents spewing gibberish on obscure internet forums.

Again. DO SOMETHING ABOUT IT, because your arrogant little internet cult is being really annoying.

Becoming ?

 

[Christopher7]

And your "29 trained professionals" claiming they know more than the authors of the reports and the experts who contributed don't mean diddly squat outside a small circle of paranoid malcontents spewing gibberish on obscure internet forums.

Wrong. The difference is, they have the integrity and courage to use their real names and credentials.

Your arrogant little internet cult is in denial.

 

[DGM]

Precisely my point. There were NO recommendations to prevent the thermal expansion or progressive collapse that supposedly occurred in WTC 7.

The recommendations are made to make a building safer, not indestructible. Building 7 preformed well above design specs. Indestructible is not cost effective and unnecessary. Welcome to the real world.

 

[tfk]

You do not understand what they mean by 'global'. If you had actually read the report, you would know that the 'global collapse' means the entire building and that started approximately 8.3 seconds after the east penthouse started to fall.

Time line using data from NCSTAR 1-9 Vol.2 pages 579-585 [pdf 241-247]
-1.3s Column 79 failed [Group 1]
-0.5s Column 80 fails [Group 1]
-0.5s Column 66 fails [Group 8]
~0.0s Column 81 fails [Group 1]
0.0s Kink in penthouse visible
1.3s Columns 77 & 78 failing [Group 2]
2.5s Columns 77 & 78 fail [Group 2]
3.5s Column 76 fails [Group 2]
4.3s Columns 59, 62, 65 & 68 fail [Group 7] G6 & G8 loading
4.5s Columns 73 - 75 fail [Group 3]
5.3s Columns 60, 63 and 69 fail [Group 8]
5.3s Column 58 failed [Group 6]
5.5s Group 3 still failing
6.3s Columns 70 - 72 failing [Group 4]
6.3s Columns 61, 64 and 67 failed [Group 6]
[FONT=&quot]At this time all the interior columns had buckled. [/FONT]

9-1 Vol.2 pg 586 [pdf 248]
After the horizontal progression of the column buckling in the core of WTC 7, the exterior columns buckled at the lower floors, completing the global collapse as follows:

Exterior column buckling spread from column to column, as loads were redistributed, until all the exterior columns had buckled between floors 7 and 14 within approximately 2s.
When all the exterior columns had buckled, as shown in Figure 12-62, the entire building above the buckled-column region moved downward as a single unit, resulting in the global collapse of WTC 7.

6.3 + 2 = 8.3 seconds


Your attempt to deny free fall acceleration, despite the fact that NIST has acknowledged it happened, is proof that you will not accept anything that proves the OCT is a farce.

How long has it been, Chris? And you are still confused about timelines?

For the REAL EVENTS, go to NCSTAR1-9, Vol 1., Section 5.7.4, Pg 273 (pdf pg 317), and the summary Table 5-3, pg 290 (pdf page 334).

You'll note that ALL TIMES are "INDEXED TO" the start of the descent of the east penthouse. This gives a solid external reference point. (time defined as 0.00 seconds). (This reference is used & reinforced in all images that give a time that says "... XX seconds after east penthouse began to move downward".)

It says that the START of the global collapse of the north wall STARTED 6.9 seconds AFTER this 0.00 time. And it says that the upper portion disappeared from view 13.5 seconds after t=0.00 sec.

The start of the REAL collapse is not visible externally. So you have to figure it out by modeling.

Go to Table 12-2 page 599 (pdf page 261) of NCSTAR1-9 Vol 2.

Distinguish between MODEL time and REAL (i.e., "Observation") Time. To identify what really happened, use "observation time".

The modeling suggests that the real collapse started approximately MINUS 6 seconds (i.e., before t = 0.00). This is the BEST estimate of the REAL start of the collapse of the building.

Adding in the 6 seconds before the east penthouse collapse, the external wall started to collapse approximately 12.9 seconds (6.0 + 6.9 seconds) after the REAL start of the building collapse.

And the roofline disappears at about 19.5 seconds after the real collapse start. And the collapse is STILL not finished.

You don't have here any number for the total collapse time, because the roofline is hidden by dust & debris cloud.

Does that clarify things?

The total collapse is measured from when column 79 starts to collapse. It takes OVER 19.5 seconds.

tom

 

[The Platypus]

Your arrogant little internet cult is in denial.

Common snake oil salesman diversion tactic, accuse others of being what they have already exposed in you...

The "truth" never needs to be sold with constant dishonesty...