The Millau viaduct is a 2,460m multi cable-stayed road bridge crossing the Valley of the River Tarn, near the Millau town in southern France. The Millau Viaduct is part of the A75 motorway linking Paris to Montpellier and Barcelona.
The Millau viaduct received the 2006 Outstanding Structure Award from the International Association for Bridge and Structural Engineering.
Designed by French structural engineer Michel Virlogeux and British architect Norman Foster, it is amongst the tallest bridge structures in the world with a pier and mast rising at 343m above ground and 270m between the road deck and the River Tarn.
- It’s construction began in October 2001 and took a little over 3 years.
- The metal deck was constructed on land at the ends of the viaduct and launched lengthwise by a hydraulic system from one pylon to the next, with eight temporary towers providing additional support. The movement was accomplished by a computer-controlled system of pairs of wedges under the deck.
- The seven pylons of the Millau Viaduct are sunk in shafts of reinforced concrete in a pyramidal shape, being divided in an overturned V, and the shrouds are anchored and distributed in semi harps.
- The viaduct is slightly curved in plan on a radius of 20,000m and with a constant 3.025% slope.
setec‘s scope of works includes:
- Assistance to the concessionaire in the technical proposal
- Project management (control of the project cost and schedule, studies and construction progress reports)
- Engineering site supervision including earthworks and foundations
- External control, check and approval of construction design
- Fire safety equipment design and implementation
- Periodic structural inspection by drone for concrete durability control and analysis of samples by the in-house laboratory
The construction of the piles, the assembling and the launching of the deck were the major strong points of this outstanding viaduct. Traditionally, one method of launching involves sliding the bridge deck over steel bearings.
However, in this case, specially designed hydraulic lift and transfer units, called translators, controlled the deck launch. While this technique was used before, it has never been attempted on a project of this size and complexity.
High-performing software developed in-house enabled detailed analysis of the wind’s actions on the structure, the launching phases of the metal deck, non-linear analysis of the reinforced concrete piles, and stability of the stiffened sheet metal panels.
Client: CEVM (Eiffage branch for the Millau Grand Viaduct)
Partners: setec tpi, terrasol, diades, lerm
Duration: 1999 – 2005