长江南京以下12.5m深水航道一期工程整治效果多水文条件物模研究

Physical model study on the first phase project of 12.5 m deep-water navigation channel from Nanjing in the Yangtze River under multi-hydrological conditions

针对太仓至南通河段两个重点碍航河段——通州沙水道和白茆沙水道的碍航特性,实施长江南京以下12.5 m深水航道一期工程,目标使12.5 m深水航道从目前的太仓港上延到南通港。通过动床物理模型试验对该一期工程的平面方案在平常水沙2 a和丰水年条件下进行了对比研究。该工程方案的通州沙工程能起到较明显的沙体守护效果,通州沙顺堤和齿坝能遏制通州沙及狼山沙沙体左缘的冲刷后退,并能遏制狼山沙窜沟的冲刷发展,且狼山沙东水道碍航浅段水深条件有所改善。白茆沙工程亦能起到较明显的沙体守护效果,能遏制沙头冲刷后退的趋势。该工程对白茆沙头部南侧的小沙包有较明显冲刷作用,白茆沙南水道进口段有一定程度冲刷,航行条件改善。对比分析表明方案在1 a丰水条件下对河床的调整趋势与两年平常水沙年条件下的试验结果基本一致,但工程效果略有减弱,总体上来说该工程方案在两种水文条件下均可以达到工程建设目标。

In view of two obstacle segments of navigation channel from Taicang to Nantong named TZS （Tongzhou shoal） waterway and BMS （Baimao shoal） waterway, the first phase project of 12.5 m deep-water navigation channel project was designed and now is under building, aiming at extending from Taicang to Nantong port. In order to study project effects, movable bed physical model is designed to optimize the project layout by comparing normal-rainfall-sedimentation-two-years and rich-rainfall-sedimentation-year conditions. TZS sub-project has obvious effect to prevent shoal erosion, training dike and tooth groins can prevent washing back of the left edge of TZS and LSS （Langshan shoal）, and the erosion development process of scour channel between TZS and LSS can also be prevented. The navigation condition of deep water channel in the East LSS waterway can be improved. BMS sub-project also has obvious effects to prevent shoal erosion as well as to change the backward trend of shoal caused by erosion. Also, small sand bar locating in south channel of BMS which cause navigation obstruction was also significantly eroded due to the projects, navigation condition of the inlet section of south channel of BMS was also improved. Conclusions can be drawn from the study that no obvious difference can be seen between the tests under normal-rainfall-sedimentation-two-years condition and rich-rainfall-sedimentation-year condition. Overall,the project can achieve the goal of engineering construction.