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This Cable-Stayed Bridge Project is on schedule to be completed January 2005. (39 month construction contract). This project is being financed privately. This project has the highest bridge piers in world. Thus the title of the Highest Bridge in the World. The tallest will be 240 meters high. Overall height an outstanding 336.4 meters. This project will consist of seven separate cable-stays.

Bridges are often considered to belong to the engineer's realm rather than the architect's. But the architecture of infrastructure has a powerful impact on the environment. The Millau Viaduct, designed in collaboration with engineers, illustrates how the architect can play an integral role in bridge design.

Located in southern France, the bridge will connect the motorway from Paris to Barcelona at the point where it is interrupted by the River Tarn, which runs through a wide gorge between two plateaus. A reading of the topography suggested two possible approaches: to cross the river, the geological generator of the landscape; or there was the challenge of spanning the 2.5 kilometers from one plateau to the other in the most economical manner.

The structural solution follows from the latter philosophical standpoint. The bridge has the optimum span between cable-stayed columns. It is delicate, transparent, and uses the minimum material, which makes it less costly to construct. Each of its sections spans 350 meters and its columns range in height from 75 meters to 235 meters - higher than the Eiffel Tower - with the masts rising a further 90 meters above the road deck. To accommodate the expansion and contraction of the concrete deck, each column splits into two thinner, more flexible columns below the roadway, forming an A-frame above deck level. This structure creates a dramatic silhouette - and crucially it makes the minimum intervention in the landscape.

Construction Date: 2001
Completion Date: 2005
Statistics: Length: 2.5 km
Height: 280 m

(Above information provided by Foster and Partners)

Architectural Design: Foster and Partners
Design Concept: SETRA
Structural Engineering: EEG Simecsol and Greisch
Contractor: Eiffage Construction
Co-Contractor: Eiffel Construction
Fabricator: Freyssinet (stay cables)
Launching Enerpac
Formwork: PERI Formwork and Scaffolding

UPDATE

16 October 2001 Beginning of construction

November 2002 Pier P2 (to be the highest) reaches 100 meters in height.

26 February 2003 Launching of the deck commences.

January 2005 Expected opening

Click on pictures for larger versions.

The world´s highest bridge piers (245 m) will be constructed using PERI formwork and climbing technology. The 2,460 m long motorway viaduct near Millau in south France is the area upon which this construction will take place. (Photo: PERI GmbH)

PERI´s solution of having only one anchor position in the concrete (2nd position above the concrete joint) up to 4 metre high concrete sections, reduces both shuttering time and presents a 50 % reduction in required anchors. The steel formwork provided a solution that met the stringent demands concerning architectural concrete. (Photo: PERI GmbH)

Single-shafted piers: The working platforms can be adjusted according to the varying cross sections of the pier, in order to provide a safe working condition for all personnel. (Photo: PERI GmbH)

Millau Viaduct, France – The world’s highest bridge

A great new work of French Structural Engineering and Spanish/American Hydraulic Technology.

In June l2001 Enerpac (Hydraulic Technology) was awarded the contract to supply the hydraulic system for lifting the temporary piers and pushing the bridge decks for the Millau Viaduct Project. Today, the works are in full process and history is being written whilst we speak: The world’s highest bridge is being build.

The bridge decks for the Millau Viaduct Project.

After considering various route options, on 28th June 1989 CETE (the Center for Technical Equipment Studies1) of Aix-en-Provence selected the 'middle' route running to the east of Millau over the River Tarn. This 'high solution', included a great viaduct, which would 'soar' over the Tarn valley without descending into it, thus avoiding the necessity for a tunnel. This has been the preferred option since 1991 because it scarcely affects the environment and offers better safety than the other option. The detailed studies commenced in 1993 and in 1994 the restricted competition was called, in which five teams of architects participated, the winning alternative being that submitted by the team comprising French engineers Sogelerg, EEG, SERF and Foster, in 1996.

The studies for the Millau Viaduct started back in 1988 with the objective of ending congestion on the A75, the motorway link between Paris and Barcelona.

From design to construction
Foster's design, impressive due to its aesthetics and size, was not exactly easy to construct without getting into cost difficulties. Supported by two abutments and seven piers, it flies the 2460 m above the Tarn valley at a central height of 245 m, with 204 m spans between the abutments and the first and last piers, and 342 m spans between the remaining piers, the heights of which range from 70 m for the first and 340 m for the third pier. The structure is multi-stayed with vertical hollow concrete members in the shape of tuning forks which support the two carriageways from the center, the carriageways having a total width of 27.35 m, sufficient for three lanes in each direction (of which only two will be put into service at the beginning) and hard shoulders on both sides.

From the driver's point of view, the viaduct has a gentle slope (3.035 % from north to south) and a gentle curve (radius 20 000 m). It is 270 m above ground level in the middle, although the central pier with its stays exceeds 340 m in height, meaning that it is 14 % taller than the Eiffel Tower.

Two types of deck were investigated, of concrete or of steel, the latter being decided on as it would be slimmer which not only leads to better aesthetics (the concrete deck would have required a height of 4.6 m), but also to greater safety, both during the period of construction and in service.

27 000 cubic meters of concrete, 19 000 tonnes of concrete-reinforcing steel, and 5000 tonnes of reinforcing steel for cables and coverings were required for its construction. It was decided to use B60 high-specification concrete for the piers and self-climbing metal shuttering of variableshape.

Once the decision of the final configuration of the works had been made on 9th July 1996, it remained to determine who would execute it and how. Several companies participated in the competition for the concession, however the French Department of Transport and Public Works opted for the Eiffage Group TP (third in size in France and fifth in Europe), which created a company specifically for its operation, the Compagnie Eiffage du viaduc de Millau. This company was awarded a 75-year operating concession in exchange for financing the works, whose cost was estimated (at the commencement of construction) at €300 000 000, plus a further €20 000 000 for the toll station located 6 km further north.

The works has been designed to withstand the most extreme seismic and meteorological conditions, its faultless operation being guaranteed for at least 120 years. The greatest constructional problems lie in the building of the deck, with a mass of 36 000 tonnes and which will be pushed out from both ends. The elements will be prefabricated at the Eiffel, Lauterbourg and Fos-sur-Mer sites, and an assembly of 64 hydraulic jacks will be used for pushing. The 'travel' involved in each of the six central spans, 342 m, made the installation of five temporary piers necessary, for the construction of which the Spanish division of Enerpac was turned to.

Hydraulic system lifts intermediate temporary piers

Seven intermediate temporary piers are required between the definitive piers in order to 'launch' the deck.

When the Millau Viaduct was being designed, Eiffel, a subsidiary of the Eiffage Group and dedicated to steel construction, estimated that seven intermediate temporary piers were required between the definitive piers in order to be able to 'launch' the deck during its construction.

Once a pier has been raised the machinery including the hydraulic system, is disassembled and moved to the location for installation of the following pier
Information kindly provided by Enerpac.
Enerpac Hydraulic System Integration for Millau Viaduct
Pushing the 4000 ton deck out into space - Check out how the deck is launched!