Critical bridge demolition
24 April 2008
Specialist Sub-Contractor Cardem DÉmolition S.A.S. Has used a fleet of Liebherr excavators during the challenging demolition of the 700 m long Winston Churchill Bridge near Strasbourg, France.
The reinforced concrete bridge, which was built during the 1960s, spanned the Dusuzeau Canal and the A4 motorway, which links Germany and France.
Technically, the most difficult part of the project was dismantling the section of bridge spanning the A4. With just 72 hours to break down and remove the 20000 tonnes of material the task was further complicated because the bridge’s design used more than 800 tonnes of steel.
Demolition of this section principally used two 395 kW R 974 B Litronic excavators, weighing 100 and 88 tonnes respectively. The smaller machine was fitted with a Montabert BRV 65 hydraulic hammer, while the second used a pair of Trevi Benne HC 100 concrete shears, which have a 2 m wide jaw and a cutting force of 330 tonnes.
Special care had to be taken to allow the pre-stressed concrete to slacken gradually. Any sudden decrease in tension could have lead to the bridge’s uncontrollable collapse.
