DIRECT ACCESS TO PORT RAMSGATE

The present access road to Ramsgate Harbour in Kent, England has become unacceptable. In 1994, a new 2.2km-long road was proposed, to link the harbour with the A28 and A253 trunk roads. It will include a 570m-long cutting, 240m of cut-and-cover tunnel, and 540m of driven tunnel. This article describes the ground investigations for the road and the design of its engineering works. The dominant rock in the area is Upper Chalk, which is usually suitable for tunnelling. Both preliminary and detailed ground investigations were conducted. Boreholes were drilled during Autumn 1994. Additional boreholes, shallow pits, and dynamic probes were used early in 1996, and on-site permeability measurements were made. Larger drillings were then made. The selected tunnel alignment was found to pass through very soft to medium-hard chalk. The cutting will descend to a depth of 14m. The cut-and-cover tunnel will be 1.3m to 6.8m below the ground. The tunnel will have two curved sections and one straight section, with cover between 6.8m and 13.0m. The carriageway will be 7.3m wide, with 1.2m-wide footways. Gullies and channels will drain water from the tunnel into soak-aways or into the sea after treatment for oil removal. The scheme is awaiting funding, but it is hoped that construction will begin very early in 1998.