长江南京以下12.5m深水航道治理工程福姜沙水道整治工程效果对比分析

Comparative analysis on the effect of Fujiangsha waterway regulation project of 12.5 m deepwater channel project in the Yangtze River below Nanjing

为达成长江口深水航道上延至南京的目标,长江南京以下12.5m深水航道二期工程在福姜沙水道实施航道整治工程,主要包括福姜沙左缘丁坝、双涧沙头部潜堤、潜堤北侧丁坝及南侧丁坝。根据福姜沙水道航道整治工程实施后的实测数据,与设计阶段数物模预测结果进行对比分析,综合分析工程前后在河势变化、流场变化、航道维护量等方面的实现情况。结果表明:1)工程实施以后,双涧沙沙头冲刷趋势得到较好的控制,上游侧沙头及潜堤北侧丁坝附近淤积明显,沙体体积明显增大。2)福姜沙左缘中上段冲淤相对稳定且总体呈现淤积态势,下段局部存在冲刷。福姜沙左缘沙体体积及面积总体有所增大,整治工程护滩固沙效果较好。3)福姜沙水道整体分流格局未发生显著变化,仅整治建筑物周边水域流场存在调整。4)航道维护量有所增加。工程达到了预期的航道整治目标,工程治理方案合理,航道整治效果符合预期,可为长江中下游潮汐分汊河段航道整治提供参考。

In order to reach the goal of extending the deepwater channel to Nanjing,the navigation channel regulation projects were carried out at Fujiangsha waterway by the phaseⅡof 12.5 m deepwater channel project in the Yangtze River below Nanjing.Regulation project is mainly including spur dike at the left edge of Fujiangsha,submerged dike at the head of Shuangjiansha,spur dike at the north side of submerged dike and spur dike at the south side.Based on the measured data after the implementation of the channel regulation project of Fujiangsha waterway,this paper makes a comparative analysis with the predicted results of the digital and physical model in the design stage,and comprehensively analyzes the realization of river regime changes,flow field changes,and channel maintenance volume and other aspects before and after the project.The results show that:1)After the implementation of the project,the scour trend of Shuangjiansha head has been well controlled.So the siltation near the sand head on the upstream side and the spur dike on the north side of the submerged dike is obvious,and the volume of sand body is obviously increased.2)The scour and siltation in the upper middle section of the left edge of Fujiangsha is relatively stable and generally presents the siltation trend,and there is scour in the lower part.The volume and area of sand body on the left edge of Fujiangsha are generally increased.Remediation project has better effect of bank protection and sand fixation.3)The overall distributary pattern of Fujiangsha waterway has not changed significantly,only the flow field around the regulation building has been adjusted.4)The amount of channel maintenance has increased.The project has achieved the expected goal of channel regulation,the project regulation scheme is reasonable,and the effect of channel regulation is in line with the expectation.It can be used as a reference for channel regulation of tidal branches in the middle and lower reaches of the Yangtze River.