跨河丁坝整治游荡性河道的工程研究

Engineering study on treating braid river by using cross-river groin

游荡性河道的整治是黄河治理工程的难点之一。黄河宁夏段二期防洪工程在Ω形河段实施截弯取直工程,首次采用丁坝跨越黄河全断面进行截流,为游荡性河道的整治提供了新的经验。本文对丁坝附近水沙特性进行了机理分析,指出防止截流过程加剧河床冲刷是该类型工程需要重点考虑的问题。依据断面水文监测与河床形态观测,及时在受冲刷河床空抛铅丝石笼进行保护,能够起到有效护底、保障截流安全的作用。提出了水文监测及施工区域的水下地形变化测量,及时预测、预判及报告河道来水、凌情情势变化情况;提出了开挖引河进行分流和双向进占截流;成功地实现了黄河合拢截流。为周边三十多万亩农田、二十多万群众的生命财产安全筑起了一道安全屏障。同时给黄河河道整治提供了理论依据,为河道治理措施的采用以及方案设计提供帮助、积累经验。

The improvement of the braid river is one of the difficulties in the Yellow River control project.The phaseⅡin Ningxia section of the Yellow River flood control project is implemented inΩshape of sectional bending straightening project.It is the first time to use the groin to intercept the river across the whole section of the Yellow River,which provides the new experience for the improvement of braid river.The water and sediment characteristics near the dam are analyzed,and it is pointed out that preventing the aggravating of the river bed scour in the closure process is the key issue to be considered in this type of project.According to the section hydrological monitoring and bed morphology observation,the timely protection in the scour bed by casting the lead wire stone cages should be carried out,which could play the effective role in the bed protection to ensure the safety of the closure.The hydrological monitoring and underwater topographic change measurement in the construction area are put forward,and the timely prediction,judgment and report for the change of the inflow and the ice status are suggested.The diversion and bidirectional inflow closure of the excavated diversion river are proposed.The closure of the Yellow River is successfully achieved.A safety barrier has been built for the safety of more than 300000 mu farmland and more than 200000 people’s lives and property.It also provides the theoretical basis for river regulation of the Yellow River,and provides the help for river regulation measures and design schemes.