Nova: Building at Ground Zero

[kevin]

I'm about half-way through the new Nova special. Very interesting. They graphically illustrate the difference between the pancake collapse that was theorized first (floor joists fail and floors collapse on top of each other) vs. NIST's progressive collapse where the joists remained attached to the exterior columns and sagged due to fire. The sagging pulled on the exterior colums causing them to collapse.

I think it really clarifies what the two failure methods they talk about in their debunking paper.

[roger]

I agree, it was a little slow at times, but it was interesting how the pancaking theory was debunked.

The only odd thing about the whole program was where they showed new buildings being developed based on the knowledge we gleaned from the attack. They didn't once show people installing explosives in the concrete or beams to be set off in some future government conspiricy.

[TV's Frank]

I was intrigued by the new tower in China, specifically the "safety" floors, or whatever they were called. Do you think this is a good idea, or just an idea that sounds good, but really wouldn't work in a real emergency?

[roger]

I wasn't sure about the safety floors. it seemed like they were designed for issues faced in that part of the world - Typhoons. Being on an open office floor in a typhoon means getting sliced apart by flying glass, scissors, etc. Being able to hide in an enclosed area seems useful.

But my honest reaction to much of this was a shrug of shoulders. These buildings are already darn safe, and they admit we can't design for an airplane crash. Wider stairwells seem like a good idea, but i'm not going to be overly concerned if I'm in a highrise with the standard 22" (or whatever the codes specify).

[kevin]

I was intrigued by the new tower in China, specifically the "safety" floors, or whatever they were called. Do you think this is a good idea, or just an idea that sounds good, but really wouldn't work in a real emergency?

refuge floors. Currently in multi-story buildings (in the US) they have areas of refuge that are typically for handicapped people (you'll usually see them as large landing floors in the emergency stairwell with an emergency phone for contacting the fire department to notify them they are there).

The refuge floors are heavily structured to withstand fires (and collapses in the immediate areas) for long periods of time. I think they're considered way stations on getting people out more safely. By providing staging areas you give people ways of changing stairwells if a particular one is blocked or places to get out of the way of fire fighters coming up, etc....

I don't believe they are designed for WTC type attacks. I'm not sure we should design for those types of events.

[Mechbob]

I was impressed that Nova admitted their previous explanation was wrong based on new evidence. I was also impressed that they allowed a discussion of possibility versus probalbility. Yes, a plane could smash into your building, but how probable is it? Take a cue from the Israelies, rather then make a building bomb proof, they do what is affordable and doable to minimise damage and casulties.

[Beerina]

I'm about half-way through the new Nova special. Very interesting. They graphically illustrate the difference between the pancake collapse that was theorized first (floor joists fail and floors collapse on top of each other) vs. NIST's progressive collapse where the joists remained attached to the exterior columns and sagged due to fire. The sagging pulled on the exterior colums causing them to collapse.

I think it really clarifies what the two failure methods they talk about in their debunking paper.


The Nova special from a couple of years ago suggested the two buildings had two different collapse methods. One seemed to have the interior column go first, the other the exterior.

[kevin]

Yeah, they showed the graphics from the previous episode and then show how the NIST findings show those are wrong. Not something a CT would do 'cause they're never wrong.

[brettDbass]

refuge floors. Currently in multi-story buildings (in the US) they have areas of refuge that are typically for handicapped people (you'll usually see them as large landing floors in the emergency stairwell with an emergency phone for contacting the fire department to notify them they are there).
Like the one in Being John Malkovich?

:duck: