长江口南港瑞丰沙整治工程对周边河势的影响

长江口南港河段近期河势发生了一些不利的变化,南港中下段河床出现深槽向北拓宽、深泓北偏,尤其是瑞丰沙中部窜沟的发展及其中、下沙体的冲刷,对深水航道的建设维护和周边水域的稳定带来了较大的影响。为控制南港下段河势不利影响,应在瑞丰沙区域实施整治工程。通过潮流数学模型、清水局部动床物理模型及其研究成果,结合河床演变分析,对瑞丰沙整治方案的治理效果及其对周边河势的影响进行分析。结果表明:瑞丰沙总体整治改进方案RFS10能够起到防护瑞丰沙、改善南港主槽航道维护条件、减少北槽底沙来量、改善南港南岸码头前沿水深维护条件、稳定长兴水道中下段码头前沿水深的效果,对圆圆沙航道维护条件基本无不利影响,对周边河势亦基本无不利影响。

Analysis of impacts of Ruifengsha regulation works in south channel of Yangtze River estuary on surrounding river regime

There are some adverse changes in the river regime in the south channel of the Yangtze River estuary in recent years, where the deep channel widening appears in the lower section of the south channel， especially the development of central string, ditch and the scouring along the middle and lower sand body. It has brought remarkable influences upon the deep waterway′s maintenance and the stability of surrounding waters. In order to solve those problems， the Ruifengsha regulation works are proposed. In this paper， the efficience of Ruifengsha regulation works and their influences on the surrounding riverbed evolution are analized by using physical model tests and numerical model tests, and by considering riverbed evolution. The analysis results show that Ruifengsha regulation scheme RFS10 can protect Ruifengsha from scouring， improve navigation conditions in the south channel， reduce bottom sand flowing into the north passage， improve maintenance conditions of the south wharf frontier in the south channel， and stabilize water depth in Changxing waterways. It has almost no effects on the maintenance conditions of Yuanyuansha waterway. And it has no potential adverse impacts on the surrounding river regime.