The Central Tunnel Contract forms a crucial part of the Central Kowloon Route. Bouygues Travaux Publics constructs an approximately 2.8km-long dual 3-lane tunnel between Yau Ma Tei and Ma Tau Kok, two cut-and-cover tunnels at Yau Ma Tei Access Shaft and Ma Tau Kok Access Shaft, a ventilation shaft, an adit and foundation for a ventilation building in Ho Man Tin; and other associated works.
The Central Tunnel will navigate underground the heart of Kowloon and will also pass adjacent to 4 MTR lines. To construct the tunnel in a densely populated area will present great challenges. This project requires meticulous project management to ensure zero interruption to the activities at ground level and the MTR service. Especially when carrying out drill & blast, an advanced double deck explosives charging techniques will be adopted at sensitive areas near the MTR tunnels and building piles to minimize disturbance to the surroundings. The complex geology also poses a challenge to the project. The excavation works will go through 7 major fault zones. Various excavation methods including drill & blast in rock, traditional excavation and heavy temporary supports in soft ground excavation will be adopted for a range of ground conditions, from hard rock to weak soils.