地震作用下高速公路立交桥桥桩对渠道倒虹吸结构的影响

针对跨线桥在地震作用下对相交的倒虹吸结构的影响，以南水北调中线工程中某相交的倒虹吸与高速公路钢管拱桥为例，根据地质、倒虹吸结构、公路桥桥桩等资料，利用ADINA有限元分析软件建立了平面有限元模型。利用时程分析法分析了水平地震作用下桥桩与土体及倒虹吸结构体系的相互作用，以及静荷载与地震荷载作用下桥桩对倒虹吸结构工作性态的影响，并对结构安全作出评价。结果表明，跨线桥对倒虹吸结构的位移值影响不超过15%，与不考虑跨线桥作用的工况相比最大加速度放大系数减少到15%，且加速度误差在工程误差范围之内；最大拉应力为混凝土最大抗拉强度的2倍多，可能出现拉裂破坏。

Impact of Bridge Pier of Highway Grade Separation Bridge on Canal Inverted Siphon under Earthquake

Aiming at the impact of flyover on intersectant inverted siphon structure under earthquake, a plane finite element model is built via the ADINA software. The data come from an example of the middle route in the south to north water transfer project, which include geologic structure, inverted siphon structure and highway bridge pier. Interaction among bridge pier, soil and inverted siphon structure system under horizontal earthquake is studied through time history method, and so is the influence of bridge pier on inverted siphon structure under static load and earthquake. Finally, it gives the evaluation of structural safety. The results show that the impact of flyover on the displacement of inverted siphon structure is less than 15%, the maximum acceleration amplification factor decreases to 15% compared to the working station without considering impact of overfly, and acceleration error is in project scope; the highest tensile stress is more than twice as likely to the highest resistant tensile stress, and cracking damage may occur.