京港澳高速公路跨北京佃起河桥防洪影响计算与分析

Calculation and analysis of flood influence across Dianqi River Bridge of Beijing-Hong Kong-Macao Expressway

结合京港澳高速公路跨佃起河桥梁改造工程实例,根据工程范围,确定计算范围与条件,在考虑河道漫溢的情况下,采用Mike21模型对桥梁改造前后河道的壅水水位及流速进行平面二维数值模拟。根据模拟计算结果,分析了河道在遇到20年一遇标准洪水时,桥梁改造前后河道壅水水位及流速的变化情况,同时分析了桥梁在设计防洪标准下(100年一遇)河道的水位及漫溢情况。经综合分析,该桥梁改造后可以明显提高河道的行洪能力,对河道自身及周边建设区的安全是有利的,可以为本项目的建设提供可靠依据,同时也为类似工程的建设提供一定的参考。

Combined with the reconstruction project of Beijing-Hong Kong-Macao Expressway bridge crossing Dianqi River,this paper adopted Mike21 model to conduct two-dimensional numerical simulation of backwater level and flow velocity of the river before and after the bridge reconstruction considering the overflow of the river.According to the calculation results,the change of backwater level and flow rate of the river before and after the bridge rebuilding is analyzed when the standard flood occurs once in 20 years.The water level and overflow of the river under the design flood control standard of the bridge(once in 100 years)are also analyzed.After comprehensive analysis,the reconstruction of the bridge can significantly improve the flood discharge capacity of the river,which is beneficial to the safety of the river itself and the surrounding construction area.It can provide a reliable basis for the construction of this project,and also provide a certain reference for the construction of similar projects.