Bouygues-Dragages is building Hong Kong’s deepest, longest and largest sub-sea road tunnel project, comprising a dual two lane subsea tunnel approximately 5.5km long.
The world’s largest tunnel boring machine (TBM) at 17.6m in diameter and two identical 14m diameter mix-shield TBMs are deployed on this project. Road tunnels were bored 50m below sea level. The tunnels will run between Tuen Mun in the New Territories and the Hong Kong-Zhuhai-Macau Bridge (HZMB) Hong Kong Boundary Crossing Facilities.
The project is part of Hong Kong’s mega-sized Tuen Mun-Chek Lap Kok Link (TM-CLKL) project. When complete, the TM-CLKL will provide a strategic road link connecting the North West New Territories with North Lantau, the HZMB HKBCF and the Airport.
The scope of works also includes:
- Reclamation of some 16.5ha of land
- Two ventilation buildings
- Construction of north and south cut-and-cover approach tunnels
TBM Technical Highlights
The TBM is equipped with three significant in-house innovations developed by Bouygues Construction’s research and development teams.
- Mobydic, a leading-edge TBM disc-cutter monitoring system
- Snake, a Bouygues-patented remote-control mechanical arm for cleaning the TBM’s cutter head
- Telemach, a Bouygues patented, automated TBM disc-cutter replacement mechanism
Key facts and figures
These are Hong Kong’s deepest sub-sea road tunnels. The twin bores run 50m below sea-level for approximately 5.5km. They incorporate 56 cross passages positioned at 100m intervals, the most for a road tunnel in Hong Kong.
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Working in an air-tight environment is the key challenge of the project. By adopting the saturation technique for the maintaining the TBM’s cutter-heads, the project team managed to minimise the health and safety risks to the workforce, while enhancing efficiency.
Cross Passages mechanised excavation
Construction of cross-passages at depths down to 50m below sea-level is another big challenge. To address this, an innovative construction method using a pipe-jacking TBM was developed and successfully implemented.
Caterpillar shaped cofferdam for south approach cut and cover tunnel
An innovative cofferdam was used for construction of the south cut and cover approach tunnels in freshly reclaimed land. This 500m long caterpillar-shaped structure comprises 15 cells with a maximum depth of 43m.
Economic benefits of the TM-CLKL
On completion of the TM-CLKL, travelling distance from Tuen Mun to Hong Kong International Airport and Tung Chung will be reduced by nearly 22km. This extra route will also be an alternative route to the airport and will strengthen the transportation network of the airport. The TM-CLKL will also enhance cross-boundary transportation and refine the regional transport network of Hong Kong, Macau, Shenzhen and Zhuhai.
Produced in partnership with Bouygues