盐城港大丰港区深水航道一期工程回淤特征研究

Backsilting characteristics of deepwater channelphase I project of Dafeng Port area in Yancheng Port

盐城港大丰港区深水航道位于苏北辐射沙洲北缘,依托西洋水道西槽建设10万吨级深水航道。大丰深水航道一期工程安排一、二阶段建设,两个阶段航道建设规模一致。基于实测水沙和地形资料对大丰深水航道开挖以后的回淤特征及原因开展研究。结果表明:二阶段航道年淤积强度为0.66 m/a,小于一阶段回淤,这与二阶段疏浚土上陆处理有关;两个阶段航道回淤时空分布特征相似,交工后前4个月航道回淤强度大,此后回淤强度有所减小,且冬季回淤略大于夏季;航道内段回淤大于外段,且高回淤区段主要位于小阴沙窜沟西侧,主要原因是内段泥沙来源相对丰富,包括外海冲刷带进来的泥沙、小阴沙冲刷泥沙以及临时倾倒区扩散的泥沙。

The deepwater channel of Dafeng Port area in Yancheng Port is located at the northern edge of the radial sand ridges in northern Jiangsu,constructing a 100,000 DWT deepwater channel relying on west trough of Xiyang channel.The Dafeng deepwater channel phase I project of first and second stages is arranged the same scale for the construction.Backsilting characteristics and sources after Dafeng deepwater channel excavation are studied based on the measured flow,sediment and terrain data.The results show that the annual silting intensity of the second stage of Dafeng deepwater channel is 0.66 m a,which is less than that in the first stage,mainly because of the onshore treatment of dredged soil.The temporal and spatial distribution characteristics of channel backsilting in the two stages are similar.The channel deposition intensity is high in the first four months after acceptance,and then it decreases,with slightly higher backsilting in winter than in summer.The backsilting in the channel inner section is greater than that in the outer section,and the high deposition area is mainly located on the west side of the Xiaoyin sandbar gully.The main reason is that the sediment sources in the inner section are relatively abundant,including sediment brought by the scouring zone of the outer sea,sediment scoured by Xiaoyin sandbar,and sediment diffused from temporary sludge throwing area.