小间距并行桥梁联合壅水影响评价分析
Evaluation and Analysis of the Joint Damming Effect of Small Spacing Parallel Bridges

针对并行桥梁现行防洪评价规范中采用的壅水计算经验公式并未考虑小间距并行桥梁联合壅水的影响，本文以实际工程为例，通过数值模拟与规范公式对比计算，分析了并行桥梁桥位间距、桥梁跨径对联合壅水高度与范围的影响。结果表明：相较于单个桥梁的桥墩布置对壅水的影响，并行桥梁的桥墩布置会产生更高的壅水高度和更广的壅水范围，小间距并行桥梁对河道防洪能力的影响不可忽视；经验公式和流速水头差法的壅水计算结果与数值模拟所得结果差距较大，需要考虑并行桥梁背景下的壅水计算公式修正。本文的研究成果为并行桥梁的设计提供了防洪计算依据，对确保并行桥梁本身和河道的安全具有现实意义。
In response to the empirical formula for calculating backwater used in the current flood control evaluation standards for parallel bridges, which does not take into account the influence of small-spacing parallel bridges on the joint damming, this paper takes actual engineering as an example and compares numerical simulation with the standard formula to analyze the influence of the spacing and span of parallel bridge positions on the height and range of the joint damming. The results show that compared to the impact of the arrangement of bridge piers for a single bridge on backwater, the arrangement of bridge piers for parallel bridges will result in higher height and wider range of backwater. The impact of small-spacing parallel bridges on the flood control capacity of the river can not be ignored. The difference between the calculation results of the empirical formula and the head difference method for backwater and the numerical simulation results is significant, and it is necessary to consider the correction of the backwater calculation formula under the background of parallel bridges. The research results of this article provide a flood control calculation basis for the design of parallel bridges, which has practical significance for ensuring the safety of parallel bridges themselves and rivers.