长江下游马当河段航道治理思路及方案

Navigation-obstruction characteristics and waterway regulation scheme of Madang river reach in the lower Yangtze River

马当河段历史上河床演变复杂,航道多变,治理难度相对较大。在对马当河段河道演变特点进行分析的基础上,分马当南水道、马阻水道及东流直水道3段,对该河段航道条件及碍航特性分别进行研究,并提出初步的治理思路。在此基础上,结合平面二维水沙数学模型,对初步方案及优化方案分别进行了效果计算。研究成果表明,通过修建棉外洲滩头护滩带、瓜子号洲左汊潜坝、洲头鱼骨坝工程、洲尾部岛尾坝及关键部位护岸等一系列工程,可以较好地解决本河段碍航问题。

The Madang river reach in the lower Yangtze River is multi-branched and slightly curving.This paper combines measured data analysis with planar two-dime nsional flow and sediment numerical modeling.Navigation-obstruction characteristics and waterway regulation measures were also researched.It revealed the following problems： The south branch of the Madang reach is the main branch where the river regime is very stable.Navigation-obstruction characteristics primarily show that the right branch entrance at the Mianwai Sandbar may have a problem of insufficient water depth.The main flow of the right branch entrance of Guazihao Island（in the area of sunken ships） may result in navigation depth deteriorating.The transition section at the entrance of the Dongliu straight waterway is narrow and shallow.These problems can be solved by a series of remedial measures,including implementing beach protection projects at the head of the Mianwai Sandbar,a submerged dike in the left branch of Guazihao Island,a fish-bone type dividing dike at the head of Guazihao Island,a spur dike at the tail of Guazihao Island,and bank protection at key position.The aims of these measures are： stabilizing branches and creating a better configuration of Guazihao Island for stabilizing the main flow of the right branch entrance of Guazihao Island and enhancing the transition shallow incision.