THE amazing Millau Viaduct
The Millau Viaduct (French: le Viaduc de Millau, Occitan: lo Viaducte de Milhau) is a cable-stayed road-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, it is the tallest bridge in the world, with one mast's summit at 343.0 metres (1,125 ft). The viaduct is part of the A75-A71 autoroute axis from Paris to Montpellier. Construction cost was approximately €400 million. It was formally dedicated on 14 December 2004, inaugurated the day after and opened to traffic two days later. The bridge received the 2006 IABSE Outstanding Structure Award.
The Millau Viaduct consists of an eight-span steel roadway supported by seven concrete pylons. The roadway weighs 36,000 tonnes (40,000 short tons) and is 2,460 m (8,070 ft) long, measuring 32 m (105 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 (1,122 ft) with the two outer spans measuring 204 m (669 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. The pylons range in height from 77 m (253 ft) to 246 m (807 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 tonnes (2,460 short tons). These sections were assembled on site from pieces of 60 tonnes (66 short 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 87 m (285 ft) tall masts.