大型输水管桥动力特性及水锤效应作用下动力响应研究

Study on Dynamic Characteristics of Large Water Pipe Bridge and Dynamic Response under Water Hammer Effect

输水管桥在水-管-桥三者的耦合作用下结构受力十分复杂,虽然国内外已建不少类似工程,但大流量、大跨度的斜拉压力输水管桥设计、建设工程案例少,可资借鉴的研究成果匮乏。以陕西省引汉济渭二期工程北干线跨越渭河的大型斜拉输水管桥为研究对象,建立了三维有限元数值分析模型,计算了斜拉桥结构与输水管道在完建和正常运行时的固有频率,分析了斜拉管桥的动力特性,进行了管、桥共振安全性复核;对管桥施加了水锤效应冲击荷载,分析了主要构件的动力响应。结果表明:斜拉桥与输水管道的固有频率相差较大,二者不会产生共振现象;水锤冲击下荷载会引起管桥局部构件的动力响应,但不会对构件产生破坏性作用,研究成果可为类似工程提供技术参考。

Under the coupling action of water-pipe-bridge,the structure of the water pipeline bridge is very complicated.Although many similar projects have been built in China and abroad,there are few cases in the design and construction of cable-stayed pressure water pipeline bridge with large-flow and large-span and there lacks of research results that can be used for reference.Taking the large-scale cable-stayed water pipeline bridge across the Weihe River on the northern trunk line of the Hanjiang-to-Weihe River Diversion Project in Shaanxi Province as the research object,the finite element numerical analysis model is established to calculate the natural frequencies of cable-stayed bridge structure and water transmission pipe during completion and normal operation,analyze the dynamic characteristics of cable-stayed pipe bridge,and review the resonance safety of pipeline and bridge;the study applies the water hammer impact load to the pipeline bridge and analyzes the dynamic response of the main components.The results show that the natural frequencies of cable-stayed bridge and water pipeline are quite different,and they will not produce resonance;the load under water hammer impact will cause the dynamic response of local components of pipe bridge,but it will not have destructive effect on the components.The study results can provide technical reference for similar projects.