Abstract: To minimize the adverse impact of bridge construction on the navigation in bridge area, two bridge sites to be selected for Yichang Yangtze River Bridge are compared in the first place, and the impacts of different bridge types on the channel in the bridge area are studied by real ship test and navigation hydraulics and ship model test. The study manifested that for both the sites, flow regime change caused by bridge construction only happens near the bridge pier and in the downstream area of the bridge pier ； while the water level rises only in a short distance of the upper reaches(the free-surface increment at 150 m upstream of the bridge is 0.1 m, yet with no obvious change downstream before and after the bridge construction). Finally, comprehensive analysis showed that the optimized No.2 bridge site scheme is more appropriate. The study provides scientific basis for the design of this project, and serves as a reference for the construction of other large cross -river bridges as well.

Key words: Yichang-Wanzhou railway  , Yichang Yangtze River bridge ,  , navigation