TECHNOLOGY TAKES THE LOAD
As part of the Channel Tunnel Rail Link (CTRL) in the UK, two 7.2 m diameter tunnels are to be bored 16 m below ground level under Renwick Road Bridge, which spans the London to Southend mainline railway, and Box Lane Ramp, which provides road access to the freight terminal. Settlement and rotation of both structures are expected during tunnel boring. To compensate for the movement and prevent damage, an automated system of bridge jacks is being designed, installed and operated by Mabey Support Systems with consultant Test Consult. The system is a network of Mat 75 Hymat hydraulic props, installed on affected parts of the bridge and ramp. The system used to prevent differential settlement of the ramp is outlined.