延河包西铁路大桥冲刷规律及其防护措施

Study on Scour Law and Protection Measures of Baoxi Railway Bridge over Yanhe River

研究包西铁路大桥冲刷规律及其防护措施,对于减少灾害,保护大桥安全意义重大。基于延河庙沟堤防工程的动床河工模型试验,观测了不同流量工况下包西铁路大桥的群桩基础局部冲刷情况,着重分析了局部冲刷成因。在此基础上,简化群桩基础模型,提出以四面六边透水框架群作为防护措施,并采用Fluent软件进行三维数值模拟,对比分析了有无防护措施两种情况下的流速分布特征。结果表明,四面六边透水框架群可大幅降低群桩基础前部及两侧行进流速,可达到减速落淤效果,该防护措施可行。

It is significant for disaster reduction and bridge protection to research the scour law and protection meas- ures of Baotou-Xi＇an railway bridge. By the movable bed model test of embankment engineering in Miaogou, Yanhe Riv- er, local scouring of pile group foundation of Baotou-Xi＇an railway bridge are observed under different flow conditions. And then the cause of local scouring is mainly analyzed. Besides, the tetrahedron penetrating frame groups are suggested to be the protection measures with simplifying the model of pile group foundation. Fluent software is used to carry out three-dimensional numerical simulation. The characteristics of velocity distribution with and without protective measures are compared. The results show that the tetrahedron penetrating frame groups can significantly decrease the flow velocity on the front and both sides of pile group foundation, which plays a role in decelerating flow velocity and dropping deposit, and the protective measure is feasible.