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Viaduc de Millau
Project timeline
28 June 1989: governmental approval of the middle route
19 October 1991: selection of the high solution, with the viaduct at 2500 m
10 January 1995: declaration of utilité publique (public usefulness), as needed to apply eminent
domain or compulsory purchase.
9 July 1996: choice of the cable-stayed bridge type
1998: decision to contract out both construction costs and future tolls to a private enterprise
16 October 2001: work begins
14 December 2001: laying of the first stone
January 2002: laying pier foundations
March 2002: start of work on the pier support C8
June 2002: support C8 completed, start of work on piers
July 2002: start of work on the foundations of temporary, height adjustable roadway supports
August 2002: start of work on pier support C0
September 2002: assembly of roadway begins
November 2002: first piers complete
25 February–26 February 2003: laying of first pieces of roadway
November 2003: completion of the last piers (Piers P2 at 221 m and P3 at 245 m are the highest
piers in the world.)
28 May 2004: the pieces of roadway are several centimetres apart, their juncture to be
accomplished within two weeks
2nd half of 2004: installation of the pylons and shrouds, removal of the temporary roadway supports
14 December 2004: official inauguration
16 December 2004: opening of the viaduct, ahead of schedule
10 January 2005: initial planned opening date
Preliminary studies
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In initial studies, four options were examined:
bypass Millau to the east, requiring two large bridges over the Tarn and the
Dourbie;
bypass Millau to the west (12 km longer), requiring four bridges;
follow the path of Route Nationale 9, providing good access to Millau but at the
cost of technical difficulties and intrusion on the town; and
traverse the middle of the valley.
The fourth option was selected by the government on 28 June 1989. It consisted
of two possibilities: the high solution, and the low solution, requiring the
construction of a 200 m bridge to cross the Tarn, then a viaduct of 2300 m
extended by a tunnel on the Larzac side. After long construction studies, the low
solution was abandoned because it would have intersected the water table, had
negative effects on the town, cost more, and the driving distance would have been
longer.
After the choice of the high viaduct's path, five teams of architects and researchers
simultaneously worked on a technical solution. The original concept for the bridge
was devised by French designer Michel Virlogeux. The architects of the bridge are
the British firm Foster and Partners. They worked together with the Dutch
engineering firm ARCADIS, responsible for the technical design of the bridge.
Costs and resources
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The bridge's construction costs amount to €394 million, with a toll plaza
6 km north of the viaduct costing an additional €20 million. The builders,
Eiffage, financed the construction in return for a concession to collect the
tolls for 75 years, until 2080. However, if the concession is very profitable,
the French government can assume control of the bridge in 2044.
The project required about 127,000 m³ of concrete, 19,000 metric tons of
steel for the reinforced concrete, and 5,000 metric tons of pre-stressed
concrete for the cables and shrouds. The builder claims that the bridge's
lifetime will be at least 120 years.
Statistics
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2,460 metre: total length of the roadway
7: number of piers
77 m: height of Pier 7, the shortest
343 m: height of Pier 2, the tallest (245 m at the roadway's level)
87 m: height of a pylon
154: number of shrouds
270 m: average height of the roadway
4.20 m: thickness of the roadway
32.05 m: width of the roadway
85,000 m³: total volume of concrete used
290,000 metric tons: total weight of the bridge
10,000–25,000 vehicles: estimated daily traffic
€4.90–6.50: typical automobile toll, as of 2005
20 km: horizontal radius of curvature of the road deck