Bridges and tunnels are good solutions to transportation problems in large cities separated by large rivers. Great success of bridge construction has been achieved in China, but large-sized immersed tube tunnel construction is still in its infancy. The design and safety of the immersed tunnel structure is an important indicator of immersed tube tunnel construction. In order to solve the safety problem of pipe joint deformation during pouring, pipe joints of immersed tube tunnels is modeled by numerical simulation method based on the research of immersed tube tunnels of Shenzhen-Zhongshan Link. The structural load characteristics of pipes during and after pouring were analyzed. Stress deformation characteristics curves of bottom plates of different pipes can be obtained through adjusting passive support when pouring. The analysis of stress deformation characteristics of steel shell offers theoretical foundation for the optimal design of all steel-concrete-steel immersed tube tunnels.
Underwater immersed tube tunnels are pipes of prefabricated reinforced concrete structures or steel shell and reinforced concrete composite structures or steel structure and concrete composite structures in the precast yard. They are floated to the site and driven into water section by section. Then, tunnels are combined and located at the excavated grooves correctly. Combined with related engineering programs, these tunnels turn into carriers for land transportation at both sides of the water body. Since the first underwater tunnel for transportation which adopts immersed tube method in the Detroit River in 1910, immersed tube tunnel has a history of over 100 years. There are around 150 immersed tube tunnels with traffic function in various countries and they are widely used in drainage projects, special underwater tunnel projects for cables and etc (Lv Y., Huang Q. etc, 2015; Zhou Y., Tan J. etc, 2001; ITA, 1993). Great changes have also taken place in cross sections and structures of immersed tube tunnels, from early circular cross sections to octagon, square, rectangle and polygon, from steel shell structure to steel shell and reinforced concrete structures, prestressed reinforced concrete structures (China Communications Construction Company Ltd., 2008; Chen Y., 2017).
