A step towards opening
A viaduct soaring twice the 141m height of the Sydney Harbour Bridge has taken an historic final step towards opening, with hydraulic technology from Enerpac being used to close the gap in its deck.
The Eiffage/Millau viaduct - with a total height of 343m - will become the highest viaduct in the world when it opens next year to form the final link of the A75 autoroute from Paris, France to Barcelona in Spain.
The last hydraulic launch of the series 18 launches of the bridge’s steel deck closed the last gap in the viaduct mid-year, connecting the North and South valley of the river Tarn near Millau in France, creating the most direct route between Paris and the Mediterranean coast. After 32 months of construction the last gap closed in May, and work began on permanently clamping the two decks for the opening of the viaduct in January 2005.
Since the first hydraulic launch of the deck 17 launches were needed to move the deck the 2460m to bridge the Tarn valley. Each of the seven piers and seven temporary piers were equipped with ingenious high-pressure hydraulic lifting devices to move the 36,000t of steel.
The Millau viaduct was designed by English architect Lord Norman Foster. The search for an aesthetic construction led Michel Virlogeux to adopt the principle of a multi-stayed viaduct, consisting of slender soaring pillars, and a very light deck, touching the valley at only seven points.
Compagnie Effiage du Viaduc de Millau was selected to carry out the project, which combines concrete and steel engineering. Hydraulic integrated solutions specialist provided the technology to lift the temporary piers, need for additional stability and for the launching of the steel deck.
The structure is multi-stayed with vertical hollow concrete members in the shape of tuning forks, which support the two carriageways from the centre, the carriageways having a total width of 27.35m, sufficient for three lanes in each direction.
Source: Building Products News.
28-Jun-2004