Paris airport collapse

“This is from a Structural Engineering listserver I participate on.

Weaknesses in the concrete used for the roof of a futuristic Paris airport terminal were the main cause of its collapse that killed four people on May 23, an official report said on Tuesday.

Citing a report that steered clear of apportioning blame, the French Transport Ministry said it was still not totally clear why the accident happened at Terminal 2E of Charles De Gaulle Airport over two years after it was built.

"The view of the commission is that the main cause of the sudden collapse is linked to the perforation of the concrete roof by the struts (supporting it)," the ministry said of the initial findings of an investigative commission.

"It is likely that this perforation was facilitated by the prior and gradual weakening of the concrete," it added.

The report did not comment on the future of the terminal, built at a cost of EUR750 million (USD$920 million) and designed to handle 10 million passengers a year.

Permanent closure of the showcase building would be a big blow to the finances and image of operator Aeroports de Paris (ADP) as it prepares for partial privatization.

Part of the terminal was opened to staff last month but ADP has pledged to demolish the cylindrical building if the structure is found to be fundamentally flawed.

A public prosecutor is carrying out a separate inquiry into the collapse, which could establish who is to blame.

The terminal was used mainly by national carrier Air France and was opened just over a year ago.

Hailed as a triumph of engineering and design, the terminal has a domed roof dotted with windows bathing it in light. But the collapse raised questions both about its design and whether it was built too fast.

The report said it was unlikely that the collapse was linked either to the foundations of the building or to the pillars on which the whole terminal was supported above the ground.”

“One guy replied, "It appears that even French concrete is weak..."”

“I'm sure the families of the dead would appreciate the joke.”

“Sorry -- that was pretty harsh.”

“sounded funny to me....”

“Actually, SE types tend not to joke about work. Public safety is at stake. I liken this joke more to cop humor. Ever been around cops in social situations? Ever been friends with a cop? They're brutal. It's great.”

“Good one, dayhiker.

The French are a joke anyway.”

“Any idea why the concrete was "weak"? Was it a bad mix? Problems in the pour? Wrong size/amount of rebar?”

“(Guess I shoulda used my "PE" handle for that post, eh?)”

“Don't know. I read somewhere that this was a large arched roof with lots of openings. Seems weird to collapse a year or two after construction. For it to be a sudden failure like that seems like a shear failure of some sort. Maybe punching shear around a column?”

“I'm sure the families of the dead would appreciate the joke.

Leave it Tilt to be so laughably effeminate right off the bat.”

“Here's a new post from the listserver

The structure appears quite unusual and - in spite of many statements to the contrary (including the ones from the architect of record) - innovative, not to say risky. Remember, an oval-shaped cross-section, quite "shallow" and wide-spanned cylindrical concrete shell profusely perforated with square openings and the wing-shaped roof attached through spaced struts (links to detailed pictures were published on this list about a month ago)?

Did it fail at those struts? Could it be some dynamic (wind) loading from the "wings" that gradually destroyed concrete at the struts?”

“Mofo!!! It was a French (from France) designer that drew up the plans for the 1976 Olympic Stadium in Montreal, Canada. 30 years later....the structure is crumbling and a huge section (something like 3 tons) fell down a couple of years back. It also had a retractable roof....which kept on ripping...was replaced 3 or 4 times at a toon of 2 million $$$ each time.

Not saying it's all his fault. Some construction companies/contractors sure ripped off a lot of cement....they were building and giving away free houses, to the govt creeps who gave them the contracts.”

“I was thinking of you last night day hiker. I was watching this show on Discovery about this Swedish scraper called the Turning Torso. It is an amazing scraper and a work of art. Ever heard of it? Here’s some pics…

http://skyscrapercity.com/showthread.php?t=78402”