长江南京以下12.5 m深水航道治理工程仪征水道整治效果分析

Regulation effect at Yizheng waterway of 12.5 m deepwater channel project in the Yangtze River below Nanjing

为达成深水航道上延至南京的目标,长江南京以下12.5 m深水航道二期工程在仪征水道实施航道整治工程,采用潜堤和丁坝的形式,守护世业洲洲头及右缘低滩,限制左汊进一步发展,增大右汊中上段航槽水流动力,改善航道条件。工程实施以后,整治建筑物掩护区内滩面淤积,左汊分流比减小2%~3%,右汊进口段航道浅段流速增加0.2 m/s左右,航道水深由10.5 m提升至12.5 m,水深条件明显改善,航道维护量较小。工程达到了航道整治目标,工程治理方案正确,航道整治效果显著,可为长江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 Yizheng waterway by the phaseⅡof 12.5 m deepwater channel project in the Yangtze River below Nanjing.The head and right marginal bank of Shiyezhou Island were protected by the form of submerged dikes and spur dikes, and the left branch further development was restricted. The flow power of the middle and upper reaches of the right branch was increased, and navigation channel conditions were improved. After the implementation of the projects, the sediment deposited in the shelter area of the regulation construction, and the diversion ratio of the left branch decreased between 2% and 3%.Furthermore, the water depth conditions are obviously improved from 10.5 m to 12.5 m due to the flow velocity in the upper right branch increased by about 0.2 m/s. The dredging amount of the navigation channel was small. The goals of the navigation channel regulation were achieved due to the correct regulation scheme, and the regulation effect was remarkable. It can provide reference for the navigation channel regulation of tidal branched reaches in the lower Yangtze River.