Abstract: Following the award in 1986 of the concession to construct and operate the Channel Tunnel, civil work on the project is more than 50 per cent complete, and on target to open to traffic in 1993. The project is being built under a single design/construct/equip contract by Transmanche Link a consortium of five British and five French contractors. The facility incorporates two running tunnels, each carrying a single rail track, and a central service tunnel. The tunnels are 50.5 km long between portals, with 38 km undersea. Special shuttle stock will allow the carriage of road vehicles, including heavy goods vehicles. The geological conditions beneath the Channel are relatively good for tunnel construction, allowing open-faced TBM's to be used on the UK side. On the French side, more permeable conditions have necessitated the use of closed-face tunnelling over limited sections, and dual mode TBM's have been developed specially for this purpose. Segmental precast concrete tunnel linings are being used for the great majority of the drives, designed to match closely the ground and loading conditions and the projected high rates of advance. The tunnelling systems are based on drive rates of up to 200 m per week, which are being achieved routinely. Construction sites have also been planned to provide support for the high rates of tunnel driving. The main tunnels are being driven from coastal sites in the UK and France, which contain all support facilities. Spoil disposal is to controlled lagoons at the coastal sites. Extensive measures have been taken to provide environmental protection and minimise impacts, particularly in the UK where the terminal and surface working sites are in sensitive areas of natural beauty or scientific value. Development and construction to date of this immense project have demonstrated the practicability of building very long, undersea transportation links.
Publication Year: 1990
Publication Date: 1990-07-01
Language: en
Type: article
Access and Citation
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot