Viaduct of Millau

Multi cable stayed viaduct with 8 spans for a total length of 2 460 m located in a site where the geo-graphical and climatic conditions are extremely severe : deep valley, heavy winds with high speeds and turbulency.

The superstructure is entirely of steel : the deck with an orthotropic plate (28 m width, 4,20 m high) and the 7 pylons (90 m high). Total steel weight : 50 000 ton.

The construction was made by launching from both valleysides and is a triple world record : launching of 171 m long spans, up to 280 m high (junction above the river Tarn) and a total weight of 20 000 ton for the last launching. The highest temporary support was 175 m.

Situation : highway A 75, upon the river Tarn. Near Millau, Aveyron (FR).

Owner : Compagnie Eiffage du Viaduc de Millau.

Execution of the works : 2001 - 2004.

Total cost of the works : 350 000 000 euro excl. vat.

Mission :

Competition : complete study of the launched steel solution (winning solution).

Production studies : global and wind calculations, calculation per launching fase, dimensioning and calculation of the deck, the pylons and the stayca-bles, dimensioning of the equipments, conception of the construction methods and the temporary works, assistance for the operations of launching, assem-bling and placing of the stays.

Award :Fib award for outstanding structure 2006.

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