湘江干流长株潭段桥梁建设对河道行洪能力影响研究

Study on the influence of bridge construction on flood discharge capacity of Changsha-Zhuzhou-Xiangtan section of the Xiangjiang river

湘江长株潭段桥梁众多,以往开展桥梁兴建对河道行洪能力影响分析时,大多考虑单座桥梁的影响,而河道众多跨河桥梁会对河道行洪能力产生累积效应.本研究依托实测河道地形和水文资料,建立湘江干流长株潭河道平面二维水动力模型,在对模型进行验证的基础上,对比分析了4组不同来流条件下桥梁兴建前、后对水位的影响.研究表明,流量越大,产生的水位雍高愈大;单座桥梁对河道水位雍高有一定的影响范围,在已有桥梁河道上,兴建新的桥梁,需合理规划桥梁位置.

There are many bridges over the Changsha-Zhuzhou-Xiangtan section of the Xiangjiang river. In the past,when analyzing the influence of bridge construction on flood discharge capacity of the river,the influence of single bridge is mostly considered,while many river-crossing bridges will have a cumulative effect on flood discharge capacity of the river. Based on the measured river topography and hydrological data,a two-dimensional hydrodynamic model of Changsha-Zhuzhou-Xiangtan section of the Xiangjiang river is established. Based on the validation of the model,the influence of four groups of different inflow conditions on water level before and after bridge construction is compared and analyzed. The results show that the larger the flood discharge,the higher the water level is;single bridge has a certain influence range on the increasement of water level. In order to build new bridges over the river which already has many bridges,it is necessary to plan the location of bridges reasonably.