Tsuen Wan TBM set for build under way

The JV of Maeda, China Railway Engineering Co (CREC) and Seli is due next month to start the TBM drive on the Tsuen Wan sewer in Hong Kong.

Assembly of the 7.72m diameter double shield, made by Seli, was being completed as T&TI went to press. The JV was completing the launch tunnel.

The Drainage Services Dept

is building the stormwater

sewer to help reduce flood risk

in parts of Hong Kong by upstream interception and discharge to the sea.

The TBM will drive a 5.1km long, 6.5m i.d. tunnel through geology expected to comprise volvanic tuffs and grandiorites. The shield is fitted with 19” cutter discs and will drive with a minimum cover of 100m.

The vertical alignment will run

to depth of 200m below the ground surface.

Tunnel lining consists of

1.6m long rings of 250mm

thick segments. The tunnelling works are due for completion late next year.

Construction works on the project also include access shafts, adits, a 40m deep vortex shaft and chambers for deaeration.