A JV between Dragages et Travaux Publics (HK) and associate company Bouygues Travaux Publics, has won two contracts to build four cable tunnels in Hong Kong for top electricity company, CLP Power.
The high voltage electricity cables tunnels, totalling 5.1km, will be built in the Kowloon and New Territories districts of Hong Kong at Kwai Chung, Tsz Wan Shan, Chi Ma Wan and the Tuen Mun river channel.
Detailed design is being carried out ready for construction to start by the end of 2002. All four tunnels will be completed in three years.
The first contract involves the construction of a 1km long tunnel in north Kwai Chung using drill and blast and a 650m long tunnel under Tsz Wan Shan Road to be built using a mixed ground TBM.
The Tsz Wan Shan tunnel will house cables to supply new homes, offices and recreational facilities at the former Kai Tak airport site.
The second contract calls for the construction of a 3.2km long tunnel, by hard rock TBM, across the Chi Ma Wan peninsula from Pui O to Tai Long Wan along the southern coast of Lantau Island and a 190m long tunnel beneath the Tuen Mun river channel using a mixed ground TBM. The Chi Ma Wan tunnel will help reinforce power supplies to Cheung Chau, allowing the installation of new power cables to replace old 33kV overhead power lines.
Dragages won both contracts using an alternative proposal in which the Tsz Wan Shan cable tunnel will be built by pipe jacking using a mixed ground TBM, replacing the original cut and cover approach. The same solution will be used to build the Tuen Mun River cable tunnel.
Dragages civil works director Luc Messier added: “The concept of these tunnels, re-designed jointly with CLP Power through an extensive value engineering exercise, is extremely challenging as it involves three completely different tunnelling techniques employed on four sites at the same time. These solutions will not only enhance the production cycles, but also reduce disturbance to the environment.”
