Research on Construction Technology for Yangtze-River Crossing Tunnel Project in Wuhan

Yangtze-River crossing tunnel in Wuhan, a key project in China currently under construction, is a twin bore, two-directional, and four lanes tunnel, with outer diameter of 11.38 m (37 ft) crossing the Yangtze-river, the largest river in China. This project uses two Compound Slurry Shields with large section to cross the Yangtze-river. The total length of tunnel is 5,049 m (16,566 ft) so it has long continuous shielding distance. The site geological conditions and the surface environment is complex, because the soil conditions of river bed are consisting of sand stratum, gravel, and shale rock. Around the tunnel job site, there are different kinds of underground pipelines, which makes the tunnel construction more complicated. Other challenges are the requirements for surface settlement and soil deformation control and environmental protection which are very strict. So with the long drive, shallow depth, and high hydrostatic pressure, this project will be facing with many unexpected difficulties. This paper mainly discusses such parts as general features of the project, its major characteristics, and the construction scheme and safety measures.