French contractor, Dragages et Travaux Publics, has broken through four months ahead of schedule on the last of four tunnels on its US$359M contract for part of the Kowloon-Canton Railway Corporation’s (KCRC) US$1.5bn 7.4km Lok Ma Chau-Sheung Shui spur railway (T&TI, July 2004, p13).
Dragages, in joint venture with associate company Bouygues Travaux Publics, was awarded the contract to build twin parallel tunnels from Sheung Shui, north under Long Valley, to Chau Tau in October 2002. The scheme actually involved four tunnel drives to take into account the construction methodology of a top-down box for Chau Tau station mid-way along the alignment.
The joint venture used Mulan, an 8.75m diameter EPB machine that was used by Dragages to build the Kwai Tsing tunnels on KCRC’s West Rail line. There was about 3.2km of bored tunnel with a further 1.7km of cut-and-cover tunnel for the western and eastern approaches.
The final section of tunnel was holed through about four months ahead of schedule. The KCRC said the early completion would allow more time for trial operation of the completed railway, which is due to be finished in 2007.
Dragages won its contract after KCRC disqualified a cheaper bid by a rival contracting group. KCRC put the contract out to tender after coming under pressure following reports it wanted to negotiate a contract direct with Dragages.
The tunnels have been built under the ecologically sensitive Long Valley wetland. They connect with an elevated structure, which continues the railway to Lok Ma Chau where a boundary crossing links Hong Kong with western Shenzhen in southern China.
