Construction of Hong Kong’s Lai Chi Kok drainage tunnel has entered its final stage following main tunnel breakthrough in December. The EUR1.3 billion project involves construction 3.7 km of 4.9 m-diameter tunnels to intercept and transfer stormwater from the uphill areas of Lai Chi Kok, Cheung Sha Wan and Sham Shui Po. Together with stormwater from Butterfly Valley, the combined flow will discharge into Victoria Harbour, near Stonecutters Island.

A number of challenges were met by contractor Leighton-John Holland JV, with the slurry TBM driving beneath four operational railway lines and through numerous foundations. Ninety construction operations were conducted under hyperbaric pressure up to 4.2 bar, which is unprecedented in Hong Kong. The supervising consultant is AECOM Asia Company Limited. Work is scheduled for completion by late-2012. For more click ch/19. Visit www.dsd.gov.hk, www.leightonasia.com and www.johnholland.com.au. 03/12.