WTC7 Revisited

[shagster]

The gash going all the way down the south facade of WTC7 is an issue that needs to be addressed by NIST and the engineering community. This is a progressive collapse that started with debris impact at the top of the building. It's reminiscent of the Ronan apartment progressive collapse. It shouldn't happen in a properly designed building. The gash indicates that WTC7 was not very robust in terms of its ability to arrest a collapse.

 

[shagster]

The collapse that occurred on the east side of WTC7 before the global collapse is another indication of the lack of robustness. This partial collapse appears to have started in the region where fires were burning near the 11th and 12th stories. The east side of the building was also the side with the longest span floors. These long span floors apparently failed as a result of the fires and the collapse progressed up to the top of the east side of the building. This indicates again that WTC7 wasn't robust in its ability to resist collapse.

 

[jammonius]

As NIST hasn't got the foggiest idea what destroyed WTC 7, perhaps some of its staff will get some ideas from this thread.

 

[Dave Rogers]

As NIST hasn't got the foggiest idea what destroyed WTC 7,

And your evidence for this claim is?

Dave

 

[DGM]

The gash going all the way down the south facade of WTC7 is an issue that needs to be addressed by NIST and the engineering community. This is a progressive collapse that started with debris impact at the top of the building. It's reminiscent of the Ronan apartment progressive collapse. It shouldn't happen in a properly designed building. The gash indicates that WTC7 was not very robust in terms of its ability to arrest a collapse.

I think your being unfair to the designers and the strength of the building. This building lasted with un-fought fires for 7 hours. Everyone got out. What more would you expect from a building that was exposed to such extraordinary circumstances?

 

[beachnut]

As NIST hasn't got the foggiest idea what destroyed WTC 7, perhaps some of its staff will get some ideas from this thread.

Wrong. NIST

An initial local failure occurred at the lower floors (below floor 13) of the building due to fire and/or debris-induced structural damage of a critical column (the initiating event) which supported a large-span floor bay with an area of about 2,000 square feet;

You are the one with out the foggiest idea; not NIST. So you need to study more. Are you in failure mode?

Fire did it; but you have no clue what their goals for studying the collapse are, do you?

But gee, they are wasting money for the CD nuts, who are lacking knowledge...

While NIST has found no evidence of a blast or controlled demolition event, it is evaluating the magnitude of hypothetical blast scenarios that could have led to the structural failure of one or more critical elements.

You lack knowledge on NIST, why?

You are the one in the fog.

 

[shagster]

I think your being unfair to the designers and the strength of the building. This building lasted with un-fought fires for 7 hours. Everyone got out. What more would you expect from a building that was exposed to such extraordinary circumstances?

I wouldn't say unfair. These are issues that need to be studied in order to build safer modern metal frame high rises. The collapse that occurred on the east side of the building where fires were burning near the 11th and 12th stories is disturbing. That collapse propagated all the way up to the top of the building. That shouldn't happen in a properly designed building. A fire burning on a couple of adjacent stories isn't extraordinary. That type of collapse could potentially happen solely due to fire on a couple of adjacent stories in other high rises of similar design and that have long span floors. I wouldn't want to be stuck in such a building during a fire or be fighting the fire inside of one.