基于双向流固耦合的倒虹吸管道水击压力波与拱式桥架组合结构动力响应分析

Dynamic response of water-hammer pressure wave and arch bridge composite structure of inverted siphon pipeline based on two-way fluid-structure coupling

在大跨度倒虹吸管道中有压闸阀关闭时通常伴随着水击现象,当水击发生时,流体与固体的耦合作用同时存在。为研究发生水击时,不同关阀时间下的压力波与考虑耦合作用时结构的动力响应情况,以大跨度倒虹吸管道与拱式桥架结构为研究对象,进行整体水力计算,基于流固耦合分析理论,将整体水力模型计算得到的水击压力波作为流体部分加载条件,在workbench平台上进行双向流固耦合分析求解桥架结构的位移、内力及应力动力响应结果。结果表明:不同关阀时间工况下,水击压力波曲线的变化趋势大致相同,结构各监测点的位移时程曲线同水击压力波曲线规律基本吻合;阀门匀速关闭时,增加闸阀的关闭时间可以作为降低倒虹吸管道水击压强的有效措施;水击力对桥架管道的影响最大,盖梁次之,拱圈最小,结构以发生顺桥向动力响应为主。

When the pressure gate valve is closed in the large-span inverted siphon pipeline,it is usually accompanied by the phenomenon of water hammer.At the same time,the coupling effect of the fluid and the solid exists.In order to study the pressure wave under different valve closing time and the dynamic response of the structure with considering the coupling effect,the overall hydraulic calculation is carried out with taking the large-span inverted siphon pipeline and the arch bridge structure as the research objects.Based on the fluid-structure coupling analysis theory,the water hammer pressure wave calculated by the overall hydraulic model is used as the loading condition of the fluid part,and the two-way fluid-structure coupling analysis is carried out on the workbench platform to solve the displacement,internal force,and stress of the bridge structure.The results show that under different valve closing time conditions,the change trend of the water hammer pressure wave curve is roughly the same,and the displacement time history curve of each monitoring point of the structure is basically consistent with the law of the water hammer pressure wave curve.When the valve is closed at a constant speed,increasing the closing time of the gate valve can be an effective measure to reduce the water hammer pressure;the water hammer force has the greatest effect on the bridge pipe,followed by the cover beam,and the arch ring is the smallest,and the dynamic response of the structure mainly occurs along the bridge direction.