九段沙北侧输沙对长江口深水航道的影响

Impact to Yangtze estuary deepwater channel by sediment transportation of north part of Jiuduansha shoal

为了研究南汇边滩促淤圈围工程对长江口九段沙滩面输沙和南导堤越堤水沙运动带来的影响,在长江口整体潮流河工模型上,采用定床输沙物理模型试验方法,研究了九段沙沿程滩面泥沙起动后的跨槽越堤输移,根据底沙在北槽的分布分析了促淤圈围工程对北槽航道的影响。研究表明:无论有无圈围工程,九段沙的底沙均能够越堤进入长江口深水航道,但促淤工程使九段沙头部进入北槽航道的泥沙略有减少,九段沙中部进入北槽航道的泥沙略有增加。

In order to study the relationship between Nanhui beach reclamation and beach sedimentation transportation on the top of Jiuduansha shoal as well as sediment transportation crossing the south training dike of the Yangtze estuary deep-water channel engineering, comparative experiments of fixed bed sediment transport before and after the reclamation are made on the Yangtze estuary model. The cross dike sediment transportation along with sediment incipient motion along Jiuduansha shoal is studied, then according to the bottom sediment distribution in the north passage, the influence on the deep-water channel in the north passage caused by the reclamation can be analyzed. The study shows that the bottom sediment of Jiuduansha shoal can be transported crossing the south training dike into the deep-water channel with or without reclamation. When the reclamation is executed, less sediment of the head part of Jiuduansha shoal is transported into the channel in the north passage, but mort sediment of the medium part of Jiuduansha shoal is transported into channel.