跨河桥防洪壅水计算及关键因素分析  

Analysis of prediction methods of backwater at cross-water bridges and impact factors

作　　者：高洪岩 杨栋 齐梅兰[2] 董言哲 杨小刚 GAO Hongyan;YANG Dong;QI Meilan;DONG Yanzhe;YANG Xiaogang(China Road and Bridge Corporation,Beijing 100011,China;Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]中国路桥工程有限责任公司,北京100011 [2]北京交通大学,北京100044

出　　处：《水利水电技术（中英文）》2022年第4期157-164,共8页Water Resources and Hydropower Engineering

基　　金：国家重点研发计划(2018YFB1600102)。

摘　　要：跨河桥引起的水位壅高是重要的洪水灾害风险因素之一,而目前关于各种壅水计算方法的准确性还众说不一。重点针对壅水计算的我国经验公式和一维水面线能量方程,研究影响计算精度的关键问题。对各方法的基本原理、关键影响因素及处理方式作了理论分析,并基于工程案例测试了局部损失系数和弗劳德数等的影响。研究发现:桥孔水流收缩和扩大系数应取随断面流量压缩比增大的值;弗劳德数小于0.4且流量压缩比小于0.3的情况下,两种方法计算的壅水高度偏差比较小;我国经验公式的经验系数与压缩比有明确的定量关系,但有必要进一步细化;弗劳德数大于0.3时,我国经验公式可能会低估壅水高度。研究认为,通过正确分析适用条件、合理定量经验参数,这两种方法在壅水计算中可达到较好的精度,且便于工程应用。The rise of flood level caused by cross-river bridges is one of the important impacts on flood disaster risk,while there are inconsistent opinions on the accuracy of various backwater calculation methods.This work focuses on comparison of the empirical formula for backwater calculation in China and the one-dimensional energy equation,and explores the key issues influencing the calculation accuracy of backwater.The basic principles and the dominant parameters are analyzed for each method.Based on a case,the impacts of local energy loss coefficients and the flow Froude number on backwater are tested.It is found that the values of contraction and expansion coefficients should be increased as the contraction ratio becomes larger;relative deviation of the backwater height calculated by the two methods is less under the conditions of the Froude number less than 0.4 and the flow contraction ratio less than 30%.The empirical coefficient in the formula of China can be quantitatively determined based on the contraction ratio,however,the relationship needs further improving.The backwater height would be underestimated by the formula of China if the Froude number is larger than 0.3.Through proper analysis of applicable conditions and reasonable determination of the value of empirical coefficients,the calculation accuracy of backwater can be improved via either the empirical formula or the one-dimensional equation.The two methods are convenient for application in engineering.

关 键 词：跨河桥 壅水高度 壅水计算方法 压缩比 收缩系数 扩大系数 

分 类 号：U442.33[建筑科学—桥梁与隧道工程]