Millau Viaduct
The Millau Bridge is a cable-stayed bridge that
spans the valley of the River Tarn near Millau in
southern France.
Designed by the French structural engineer Michel Virlogeux and British architect Norman Foster, at 300m (984 feet) it is
the highest road bridge in the world, weighing 36,000 tonnes. The central
pillar is higher than the famous French icon, the Eiffel Tower. It
was built in 16 October 2001 and opened to traffic on 16 December 2004.
The bridge took only three years to complete with new
engineering techniques being employed. The traditional method of building a
cable stay bridge involves building sections of the deck (roadway) and using
cranes to put them in position. Because of its height, 900 feet above the
valley floor, a new technique had to be developed.
First, the towers were built in the usual way, with steel
reinforced concrete.
The road way was built on either side of the valley and rolled into position, until it met with precision in the centre. This technique had never been tried before and it carried engineering risks. However, it proved to be an efficient method of deploying the roadway.
The road way was built on either side of the valley and rolled into position, until it met with precision in the centre. This technique had never been tried before and it carried engineering risks. However, it proved to be an efficient method of deploying the roadway.
The project required about 127,000 cubic meters of
concrete, 19,000 tonnes of steel for the reinforced concrete and 5,000 tonnes
of pre-stressed steel for the cables and shrouds. The cost of
construction was approximately €400 million.
President Jacques Chirac (the president of france). In
his speech he praised the design saying that it was a ‘monument to French
engineering genius’ and ‘a miracle of equilibrium’.