Civil Engineering Reference
In-Depth Information
(2004)
In the early morning hours of May 23, 2004, passengers in Terminal 2E at the Charles
de Gaulle Airport in Paris reported loud noises that caused them to look up at the
overhead concrete structure. What they saw, large cracks in the precast concrete shell
structure, caused alarm leading to the evacuation of hundreds of passengers. Shortly
after the initial discovery, a large section of the concourse collapsed resulting in
several fatalities. The magnitude of the collapse at such a high profile public use
building that had been open only 11 months led to a major investigation of Terminal
2E including the design process, construction sequences, and material properties.
Construction consisted of a combination steel truss on the exterior with a 30
cm (12 in.) thick precast concrete shell vault on the interior. A flattened area existed
at the top of the vaults. The system was discontinuous at several locations due to
openings for windows and skylights and intersecting corridors. The entire roof
system was supported on a series of concrete column posts connected with concrete
beams that were supported on sliding bearing connections. This section of Terminal
2E was 34 m (111 ft) wide and 650 m (2130 ft) long. Covering most of the exterior
was a metal skin supported by steel framing and posts that was not rigidly attached in
order to permit some thermal movement. Steel posts supporting the metal roof skin
were recessed 10 cm (4 in.) into the precast shell sections.
As with many major failures in the historical record, technical experts
investigating the collapse indicated a series of problems existed, both procedural and
technical / structural as the cause of failure. Chief independent investigator, Jean
Berthier, questioned the existence of proper design and construction processes in a
project where the owner, project manager and architect were essentially the same.
The terminal was designed by renowned French architect Paul Andreu, who was
Director of Aeroports de Paris (AdP) at the time of the design. State owned AdP not
only designed the building but they managed the construction, virtually eliminating
the distinction between architect and client in this particular case.
Detailed modeling and study by the investigators concluded two possible
trigger points of the collapse from the list of problems and deficiencies noted above.
Berthier's team concluded that on the south side, the edge beam supporting the shell
fractured, falling off its supports and collapsing. The other likely trigger mechanism
was the punch through of several embedded steel struts which introduced high
stresses and fatigue into the concrete shell partially as a result of thermal movement
in addition to the existence of concrete creep stresses in the shells.
Reconstruction efforts for Terminal 2E consisted of a combination of
demolition, modification and reconstruction of the roof and some related portions of
the building.
