长江南京以下12.5m深水航道二期工程口岸直河段选槽数学模型

Mathematical model study on choosing flume of 12.5 m deepwater channel phase Ⅱ project of Kou'an straight reach along Yangtze River downstream Nanjing

采用平面二维潮流泥沙数学模型的技术手段,配合长江南京以下12.5 m深水航道二期工程口岸直河段选槽专题研究,选取典型的水沙计算条件,进行了选槽方案实施前后潮流泥沙运动的对比计算分析及设计航槽内疏浚位置回淤量计算,为鳗鱼沙河段选槽方案的确定提供科学依据。数学模型计算表明:方案1具有护滩和增加航道浅区段水流动力的效果,对周边水域影响较小,同时考虑航道的可维护性、与交通组织适应性、与沿岸港口的适应性几个方面,推荐方案1(左右汊单向航道)作为口岸直鳗鱼沙河段12.5 m深水航道选槽方案,但建议该方案左槽中段航线位置稍向左岸调整,以适应深槽变化趋势。

Using technical means of 2-dimensional tidal current and sediment mathematical model, with monographic study on choosing flume of 12.5 m deepwater channel phase Ⅱ project of Kou＇an straight reach along Yangtze River downstream Nanjing, selecting typical calculation conditions of water and sediment, the contrast calculation and analysis are conducted of tidal current and sediment movement before and after the choice of flume, along with back silting quantity calculation within the position dredging of the design channel, providing a scientific basis for the scheme determination of choosing flume for Manyusha shoal reach. The calculation of mathematical model indicates that： plan 1 has effect on beach protection and increasing the flow dynamics of the channel shallow section, with less influence on surrounding waters. Considering the maintainability of the channel, adaptability of the traffic organization and adaptability of the coastal ports at the same time, plan 1 is recommended as scheme for choice of flume （unidirectional channel in left and right branch） of 12.5 m deepwater waterway in Kou＇an Straight reach Manyusha shoal reach, while in the scheme a slight adjustment to the left bank of the middle route in the left flume is suggested, adapting to the change trend in the deep flume.