平陆运河与沙坪河交汇河段通航水流条件试验研究

Experimental research on navigable flow conditions in intersection of Pinglu Canal and Shaping River

平陆运河沿线支流众多且支干落差大,支流突发洪水对运河通航水流条件影响较大。选取入汇角度大、支干汇流比大、河底落差大的沙坪河入汇河段为研究对象,采用1:50正态河工模型试验,对沙坪河入汇河段通航水流条件进行系统试验研究。模型试验结果表明,受支流突发较大洪水和支干河底落差较大影响,运河航道内横向流速大且流态紊乱,加之支流口上游铁路桥限制,消能措施布置长度有限,不能达到较好的消能效果。分析认为主要问题在于支流洪水汇入运河后运河横向流速较大,因此治理方案主要解决“调顺水流+消能”的问题。在交汇处布置导流堤、透空消能墩、底部斜向透空式隔流堤,在支流内采取消力池、消力槛等消能措施并进行系列方案对比试验,发现优化方案Ⅲ的通航水流满足通航要求且不会对支流内铁路桥造成影响。

There are many tributaries along Pinglu Canal with large branch drop,and the sudden flood of tributaries has a great impact on the navigable flow conditions of the canal.This paper selects Shaping River reach with large inlet angle,large branch and trunk confluence ratio and large river bottom drop as the research object,and adopts 150 normal river model test to carry out systematic experimental study on navigable flow conditions in this reach.The model test results show that due to the large sudden flood of tributaries and the large bottom drop of the branch river,the lateral flow velocity in the canal channel is large and the flow pattern is disordered.Coupled with the restriction of the railway bridge upstream of the tributary estuary,the arrangement length of the energy dissipation measures is limited,and the energy dissipation effect cannot be achieved.The analysis suggests that the main problem is that the lateral flow velocity of the canal is large after the tributary flood flows into the canal,so the treatment plan mainly solves the problem of“regulating water flow+energy dissipation”.Diversion levees,diversion piles and bottom inclined permeable separation levee are arranged at the interchanges,and energy dissipation measures such as deadling pool and dissipation sill are adopted in the tributaries.A series of scheme comparison tests are carried out.It is found that the navigable water flow under optimization schemeⅢmeets the navigable requirements and does not affect the railway bridge in the tributaries.