Advancing under London

Bored tunnels account for more than 20 percent of the Channel Tunnel Rail Link, the high-speed rail line that will connect the Channel Tunnel with London upon its completion in 2007. In addressing the challenging subsurface conditions present at the sites of three tunnels, the designers have made advances in such areas as the large-scale use of fiber-reinforced precast-concrete linings and the design of shotcrete linings.