SEDIMENTATION PROBLEMS RELATED TO REGULATION OF DEEP CHANNEL IN THE YANGTZE ESTUARY

摘要

The deepwater navigation channel is a great project in China. The project is divided into three stages. The target water depths are -8.5m, -10m and -12.5m respectively. The total investment is 15,500,000,000 RMB yuan and the duration of construction is 9 years. The one-stage project started to be built in January 1998 and was completed in March 2000. The two-stage project started to be built in October 2003. In this paper, the dynamic conditions and sedimentation of the Yangtze Estuary are introduced. According to the similarity conditions of tidal currents and bed loads, a movable bed physical model of the Yangtze Estuary is designed to study the layout of regulating project of the deep channel and simulate bed load movement. In order to predict the siltation in the channel after regulation, a 2D numerical model is presented, in which total sediment transport, the actions of tidal currents and wind waves, the effect of salinity are considered. The annual siltation and short-term siltation in one-stage channel are calculated and compared with the dredging volumes in prototype.