ABSTRACT
Gongbei Tunnel is one section of Hong Kong-Zhuhai-Macao Bridge connecting Zhuhai city and Macao, and undercrossing the Gongbei Port. The tunnel is shallow embedded with a large cross-section of 345 m2 built in saturated soft soil. To guarantee the construction safety and avoid the damage of the surroundings, the Freeze-Sealing Pipe Roof method, which is an innovative combination technology with pipe jacking roof for per-support and ground freezing for waterproof, is applied in the excavation of Gongbei Tunnel. The frost heaving of the soil surround the tunnel would increase the contact pressure between the soil and primary support. The primary support and the secondary lining have different mechanical response in two different contact modes: complete contact and incomplete contact. The loading transfer between the primary support and the secondary lining is more efficient in the complete contact mode.
