基于MIKE21FM的某城际铁路跨河桥阻水分析

Analysis of Water-blocking of an Intercity Railway River-crossing Bridge Based on MIKE21FM

为分析铁路桥梁对河道行洪的影响程度,以北三河水系某河道上跨河城际铁路桥为例,搭建MIKE21FM水动力模型来模拟建桥后设计洪水的流场,基于模型计算结果提出了阻断流量比的概念和计算方法,并分别计算了桥梁阻水比、阻断流量比等指标。经分析可知,对于有主槽的复式断面河流,阻断流量比更能客观地反映桥墩建设对河道行洪的影响程度,分析结果对优化桥墩布置方案和防洪评价工作均具有重要的指导意义,可为同类防洪评价项目提供参考。

In order to analyze the influence of railway bridges on river flood discharge,the MIKE21FM hydrodynamic model was established to simulate the flow field of design flood after the construction of the bridge,taking the intercity railway bridge crossing a river in Beisanhe River System as an example. Based on the calculation results of the model, the concept and calculation method of flow-blocking ratio is proposed,and the water-blocking ratio and flow-blocking ratio are calculated. According to the analysis,the flow-blocking ratio can objectively reflect the influence of pier construction on river flood discharge for the multi-section river with main channel. The analysis results have important guiding significance for the optimization of pier layout scheme and evaluation on flood control,and can provide reference for similar evaluation on flood control.