[关键词]
[摘要]
为探究桥梁雍水与桥洞堵塞对洪泛区淹没情况的贡献,以山区河道梅溪上的八座桥梁为例,借助FLOW3D模型构建了精细化三维河道与桥梁模型。模型经验证,模拟值的绝对误差平均值小于0.05 m,Nash系数大于0.77,表明模拟结果良好。分别计算了各桥不同重现期下的雍水值,模拟了桥洞堵塞程度的影响。结果表明:整体来看,上游桥梁雍水值大部分大于下游桥梁点位。七号桥的雍水影响最大,在20 a,50 a和100 a重现期,对桥前洪泛区最大淹没水深的贡献比分别达到了15.1 %,18.5 %与22.7 %;桥孔堵塞程度增加的比例与桥前水位增量基本呈线性关系。相对于50 a无堵塞的情况,七号桥堵塞20 %对桥前洪泛区最大淹没水深的贡献比又增加了21 %,桥前平均水位甚至大于100 a无堵塞的洪水水位。本研究可以为防洪减灾与桥梁安全防护提供参考。
[Key word]
[Abstract]
In order to illustrate the contribution of bridge backwater of piers and bridge clogging to flooding, eight bridges on the Meixi river in Honglai town were selected. A refined 3D model was built by FLOW3D model. It is verified that the average absolute error of the simulation values is less than 0.05 m, and the Nash coefficient is greater than 0.77. The results show that, most of the upstream bridges backwater values are greater than the downstream bridges. Among them, the backwater of bridge No.7 has the greatest impact. When the return period is more than 20 a, its contribution to the floodplain maximum inundation depth is more than 15 % in front of the bridge No.7. The increasing proportion of the bridge hole clogging degree is basically linear with the increase of water level in front of the bridge. Compared with the situation without clogging, the contribution ratio with 20 % clogging to the floodplain maximum inundation depth in front of the bridge will increase 21 %. Average water level in front of bridge No.7 with 20 % clogging in 50 a is larger than that in 100 a without clogging. This study can provide reference for flood control, disaster reduction and bridge safety.
[中图分类号]
TV871
[基金项目]
“十三五”国家重点研发计划项目(2016YFC0401308);国家自然科学基金面上项目(51779007, 41671018)Funds: National Key Research and Development Program of China during the 13th Five-year Plan Period (2016YFC0401308); National Natural Science Foundation of China (51779007, 41671018)