Millau Viaduct France (In French le Viaduc de Millau) is one of the most awesome civil engineering project. It is a large cable-stayed road-bridge that spans the valley of the River Tarn near Millau in France. It was designed by structural engineer Michel Virlogeux and architect Norman Foster. One of the summit of this bridge is at a height of 343 meters)1125 ft) which makes it is the tallest vehicular bridge in the world.
The Millau Viaduct consists of an eight-span steel roadway supported by seven concrete pylons. The roadway weighs 36,000 tons and is 2,460 m (8,100 ft) long, measuring 32 m (100 ft) wide by 4.2 m (14 ft) deep, making it the world’s longest cable-stayed deck. The six central spans each measure 342 m (1,120 ft) with the two outer spans measuring 204 m (670 ft). The roadway has a slope of 3% descending from south to north, and curves in a plane section with a 20 km (12 mi) radius to give drivers better visibility. It carries two lanes of traffic and one safety lane in each direction.
The pylons range in height from 77 m (250 ft) to 246 m (810 ft), and taper in their longitudinal section from 24.5 m (80 ft) at the base to 11 m (36 ft) at the deck. Each pylon is composed of 16 framework sections, each weighing 2,230 tons. These sections were assembled on site from pieces of 60 tons, 4 m (13 ft) wide and 17 m (56 ft) long, made in factories in Lauterbourg and Fos-sur-Mer by Eiffage. The pylons each support 97 m (320 ft) tall masts.
The pylons were assembled first, together with some intermediate temporary pylons, before the decks were slid out across the piers by satellite-guided hydraulic rams that moved the deck 600 mm every 4 minutes. Then the masts were driven over the new deck, erected on top of the pylons, connected to the deck and the temporary pylons removed.
Construction began on 10 October 2001 and was intended to take three years, but weather conditions put work on the bridge behind schedule. A revised schedule aimed for the bridge to be opened in January 2005. The viaduct was inaugurated by President Chirac on 14 December 2004 to open for traffic on 16 December, several weeks ahead of the revised schedule.