A few weeks ago my business partner, a CalTech-trained engineer, passed through the section of the Charles de Gaulle international airport that collapsed Sunday. Having nothing better to do, he spent some time looking at the structure from the inside, and then turned to his wife and said "I have no idea what is holding this thing up. It looks like a really bad idea."
The problem it seems, is that concrete is particularly brittle and the squashed-oval shape, with much of the strucure punctuated by large openings, leaves very little load-bearing structure, and that little is under horrendous stress. The stress comes from both the many openings in the walls and by the fact that nealy all the gravitational tension is concentrated in the deep bend half-way up. Where steel or aluminum will bend quite a bit before failing, concrete either holds or comes apart.
Struts and guys and other supports won't fix it either -- it will just increase the stress (at the attachment points). They already had tried adding bands around it -- these failed. There is no choice but to tear it down.
When I pointed out in the article on the collapse that the architect had "no idea" why it had collapsed, he said "Obviously not." The blame should fall on the architect, the civil engineers, and probably the government, but watch them blame the construction firm for this design failure.
"The blame should fall on the architect, the civil engineers, and probably the government, but watch them blame the construction firm for this design failure."
Yeah. They used substandard anti-gravity generators.
Posted by: McGehee at May 25, 2004 02:18 PM