长江老海坝抛石护岸工程对河势的影响研究

Study on the river regime influences by riprap revetment along Laohaiba Reach of the Yangtze River

为研究洪水期抛石护岸工程对河势的影响,采用MIKE21平面二维水沙数学模型,对长江老海坝有无抛石护岸工程两种工况下的水流特性和深泓线的变化进行对比分析。结果表明,工程对抛石护岸区附近的水流特性影响较大,距近岸起点越远,断面水位和平均流速变化越小。抛石护岸工程区距近岸起点0-600 m范围内水位壅高明显,最大壅高0.028 m,0-400 m范围内断面平均流速明显减小,最大减小0.2 m/s。工程后,澄通河段区域水位及流速变化不大,深泓线总体走势不变,深泓摆动不大,在浏海沙水道深泓有所左移,有利于局部河势稳定。

Two-dimensional numerical model of flow and sediment in MIKE 21 software was used to study the effects of riprap revetment on river regime during flood period. The paper analyzes the differences of the characteristics of flow and thalweg between with and without riprap revetment conditions along Laohaiba reach of the Yangtze River. The results indicate that the water levels and velocities change obviously in the area of riprap revetment. The farther away from the starting point is,the smaller the impact on the flow characteristics.Water level increases greatly in the range from the starting point 0 to 600 m,the maximum increase value is0. 028 m. Mean velocity decreases in the range of 0 to 400 m,and the maximum decrease value is 0. 2 m/s.The water level and velocity don＇t change significantly in the large range of Cheng-Tong Reach. The overall trend of the thalweg is stable,and there is a little swing of thalweg to the left in Luihai shoal waterway,which is beneficial to the stability of river regime.