建桥对河流洲边滩的影响

Influences of bridge building on bottomland evolution in rivers

依据有关桥梁的河工模型试验结果及实测资料,分析了建桥后建桥河段的水流、泥沙的冲淤变化,探讨了建桥对洲边滩的影响.结果表明,建桥后桥址附近河段的水位、流速流向、单宽流量均会发生变化,且距桥址愈近变化愈大;不同桥型对洲边滩的影响不同,对目前多采用的主跨大、边跨墩数多的桥型,建桥后易形成边滩或使原有边滩淤大淤高.

Based on the experimental results of river model and measured data of related bridges, variations of discharge and sediment movement in the bridge reach after bridge building are analyzed, and influences on bottomland are discussed. Results show that after the bridge building, the water level, velocity, flow direction and unit discharge in the reach near the bridge have changed, i.e. the closer to the bridge, the bigger the influence, and that different bridge types have different effects on the bottomland. For the bridge with a big main span and dense piers in side spans, which is usually adopted at present, it is easy to form new side bottomland or cause the existing side bottomland to become bigger and higher.