The 5.1km Dalian Bay Undersea Tunnel across the mouth of Bohai Bay in northern China opened to traffic this week, China Daily reports.
The tunnel in Liaoning province consists of 18 tubes, each weighing about 60,000 tonnes, that carry a six-lane urban expressway with a maximum speed of 60km/h.
Qian Qihu, a member of the Chinese Academy of Engineering, told the paper that the decision to use immersed tubes was taken in 2013. He said the project had “filled a number of industrial gaps and created a number of records in the field of cross-sea immersed tunnel construction”.
He said: “In the past 10 years, the construction of China’s submerged tube tunnel has changed from a ‘following’ to a ‘staying abreast’ and finally to a ‘leading position’.”
The project was carried out by First Harbour Engineering, a subsidiary of state-owned contractor China Communications.
- See inside the tunnel:
Song Jiangwei, an engineer with First Harbour, told China Daily that builders had to reckon with the region’s complex geology and temperatures of below –20°C, which had necessitated the development of a number of “new structures and technologies”.
The new link is expected to help alleviate traffic congestion and expand the space for urban development in Dalian, and help the economic development of the northern side of the bay.