Steel rods punched through concrete in Paris airport terminal

The French Transport Minister, Gilles de Robien, has suggested that the collapse of Terminal 2E at Charles de Gaulle Airport in May could be due to the unusual architectural design, which is of “great complexity.”
According to coverage in the New York Times (July 7), a preliminary investigative commission has found that the collapse may have been caused by steel rods punching through the building’s elliptical concrete shell. Completed a year ago for US $900 million, the terminal was designed using technology developed for underground tunnels.
The design used steel hoops attached with short steel rods to the exterior of the “tunnel” to simulate the pressures that would have been exerted on the structure had it been built underground.
However, there is also the question of whether the rods perforated the shell as a result of the collapse, rather than being the cause. The 100-foot section that collapsed is near three openings for walkways and is very assymetical.
The commission’s preliminary report is based on outside observations, since engineers still haven’t been able to enter the building due to its instability.
A separate criminal investigation is to determine who is responsible for the disaster, which resulted in four deaths..