The Millau Viaduct is considered one of the greatest engineering achievements in the world. It is the tallest bridge ever built, recognized as a marvel of engineering and architecture.
It is located in Aveyron, France, and forms part of the French A-75 motorway. Construction of this impressive structure spanned from 2000 to 2004, and it was inaugurated on December 14th of that year. However, its actual development took 14 years.
One of the features that makes it stand out from other structures is the large cables (called shrouds) that ensure the stability of the bridge by helping to support the deck (also known as "the backbone").
The project was carried out by the French company Eiffage, but the initial idea was put forward by the French civil engineer, Michel Virlogeux, a specialist in bridges who, up to that point, had designed no less than 100 bridges, including the one in Normandy, in northern France.
It was commissioned by the British architect Lord Norman Foster, a prolific British architect considered one of the most accomplished architects of his generation. In 1999 he was awarded the Pritzker Architecture Prize, often called the Nobel Prize of architecture.
The combination of a visionary architect and a highly qualified structural engineer was considered the perfect mix to carry out the ambitious project.
The bridge is 343 meters high and 2,460 meters long, spanning the Tam River. This masterpiece of architecture and civil engineering employed a wide range of advanced techniques, including:
- Lasers.
- GPS.
- High-strength concrete
- Various innovative materials.
It is a cable-stayed motorway viaduct, made of concrete and steel, that spans the Tarn Gorge valley near the city of Millau in southern France. The viaduct forms part of the A75 to A71 motorway between Paris, Béziers, and Montpellier in France.
Its construction cost approximately €310 million and it was officially opened in 2004. The viaduct is considered a great technical and architectural feat and has won several awards since its inauguration, including the 2006 Outstanding Structure Award from the International Association for Bridge and Structural Engineering.
Other information about the work
The viaduct was built to combat congestion on local roads around Millau during the summer holidays. Before its construction, traffic had to descend into the valley to cross the area.
After a consultation period in which offers were submitted by several architecture and engineering consortia, the offer from Norman Foster and Michel Virlogeux, through their companies Sogelerg, Europe Etudes Gecti and Serf, and the architects' consortium Foster + Partners, was considered the best.
Construction began in 2001 and took three years to complete. It was inaugurated in December 2004. At the height of construction, 600 master craftsmen were recruited to bring the viaduct to fruition.
The bridge's construction was financed by the construction company, Eiffage, in exchange for the right to collect tolls for the next 75 years. However, if toll costs become too high, the French government reserves the right to take control starting in 2044.
The viaduct used 127,000 cubic meters of concrete, 19,000 tons of steel to reinforce the concrete, and another 5,000 tons of prestressed steel for the cables and stays. Its builders have stated that the bridge should last at least 120 years.
The viaduct has seven concrete pillars supporting its superstructure of 16 steel roadway sections. The viaduct has six roadways with shoulders, all held together by 154 steel cables.
Sources:
