Two of the most complex West Rail stations are at Mei Foo and Nam Cheong in West Kowloon. Nam Cheong is the southern terminus and will provide a direct interchange to the Mass Transit Railway's (MTR) Tung Chung Line which runs through the site. The presence of these lines at ground level and the busy West Kowloon Expressway viaduct above made the work on Balfour Beatty-Zen Pacific's £198M contract extremely sensitive.
Part of the station structure has been constructed under and around the Tung Chung/Airport Express track and beneath the road viaduct so excavation work had to be carried out without producing more than 25mm of settlement. To complicate matters, the station's 350m by 80m footprint also runs across three major water cooling mains for the MTR's nearby underground lines.
The mains run through reclaimed ground under the station so there was a heightened risk of settlement.
'Construction work and piling did trigger some accelerated consolidation and we had to slow down a bit, ' says KCRC southern section project manager CN Fung.
'We had to be very careful, but the risk has been eliminated, ' he adds.
Just to the north, civils work at the Kier-Zen Pacific's HK$1.2bn Mei Foo interchange with MTR's Tsuen Wan line is giving way to follow on trades after a year of intensive construction actitvity. The station's 33,000m 2footprint has been squeezed between the busy Ching Cheung Road and under a busy expressway viaduct. It also crosses above MTR's underground Tsuen Wan tracks, so excavation and piling work had to be sequenced to avoid disrupting services or causing damaging settlement.
At the north end of the station, contractors are excavating a short cut and cover section in the cramped space under the Ching Chung road. This involves shifting traffic lanes within the confines of the road route, which hugs a steep sided hill.
Beyond Mei Foo, construction work on the underground Tsuen Wan West Station is substantially complete. Built by Penta OceanKier within a propped diaphragm wall in reclaimed land, the structure is 390m long and 40m wide and rests on 84 bored piles and 44 H-piles.
Southern section stations contractors and consultants Nam Cheong:
Contractor Balfour Beatty-Zen Pacific JV KCRC design consultant:
Hyder Consulting Mei Foo:
Contractor Kier-Zen Pacific JV KCRC detailed design consultant:
Hyder Consulting Tsuen Wan West:
Contractor Penta Ocean-Kier JV KCRC detailed design consultant: