江湖汇流段桥墩布设对行洪安全的影响研究

Study towards the Influence of Bridge Pier Layout on Flood Carrying Safety in River-Lake Confluence Section

摘要: 江湖汇流段历来是防洪较为敏感河段，在此修建的桥梁工程，需采取桥墩布设尽量减少数量、规避主泓区域的设计措施，降低对行洪安全的影响。采用数学模型及物理模型两种方法分别分析了采用这一新理念设计的特大桥工程对江湖汇流区河道行洪的影响程度，并对两种模型的成果进行对比分析。结果表明，工程建设对主槽水位、流速影响较小，断面流速分布形态改变甚微，工程前后水流主流线没有发生变化。经比较两种方法计算结果差别不大，定性结论一致。两种方法取得成果无本质区别，均可以作为工程影响程度分析的基础数据，为设计及河道管理提供参考。

Abstract: The confluence section of the Yangtze River and the Dongting Lake has always been a sensitive section for flood control, where schemes need to be adopted to calculate the impact of the project on flood dis-charge and river regime. In this paper, both mathematical and physical models are compared in analyz-ing the impact of the construction of a super-large bridge on river flood discharge in the confluence area of rivers and lakes. The results show that the construction has little effect on the water level and velocity of the main channel and the distribution pattern of cross-section velocity changes little, and the main flow line has not changed before and after the project. The comparison shows that the results between the two methods are not much different and the qualitative conclusions are consistent. There is no essential difference between the results obtained by the two methods, which can be used as the basic data for the analysis of Engineering impact degree and provide reference for design and river management.