为解决南水北调中线工程在加大流量输水期间出现跨渠桥梁密集段水位壅高、影响工程输水能力问题，选 取双洎河倒虹吸-梅河倒虹吸约 13.233?km 渠段为输水试验段，以试验段内 5 座典型桥梁为试点，运用流体力学理 论进行流线型导流罩基础体型与结构设计并对设计方案进行比选优化，运用数值模拟及原型观测试验研究方法 进行桥梁墩柱导流罩应用效果研究。通过原型观测试验，分析验证 5 座桥梁加装导流罩后试验段的流态及过流 能力。结果表明：5 座桥梁安装导流罩后，桥梁墩柱附近流态显著改善，试验段水头损失减少 64.4%，综合糙率减 少 8.0%，试验段内过流能力提高 8.71%。研究成果可为长距离明渠输水工程中已建桥梁墩柱加装导流罩体型设 计以及附近流态原型观测方法提供参考与技术支撑。

In order to solve the engineering problem that the high water level in the intensive section of the cross-channel bridge affected the water transport capacity of the project during the period when the operating flow of the Middle Route of the South-to-North Water Transfers Project exceeded the maximum designed flow for the first time in 2020, the 13.233 km section from Shuangji River inverted siphon to Mei River inverted siphon was selected as the test section, and five typical bridges of the test section were selected as the test objects. The numerical simulation and prototype observation test research methods were used to design and study the application effect of the bridge pier guide dome. The basic type of the guide dome was designed according to the hydraulic theory. The 3D hydrodynamic model parameters were calibrated using the prototype observation data of the unguided dome. Meanwhile, the schemes of different guide dome sizes were further compared and selected by numerical simulation, and the optimal scheme was obtained. Through the prototype test, the optimization of the flow pattern and the improvement of the water transport capacity of the test section of five bridges after installation of the guide domes were analyzed and verified.The results showed that after the installation of the guide dome, the flow pattern near the pier of the five bridges was obviously improved, the head loss of the test section was reduced by around 64.4%, the comprehensive roughness was reduced by around 8.0%, and the flow capacity of the test section was increased by around 8.71%, which further verified the reliability of the numerical simulation.The method of bridge pier guide dome design and prototype observation can also be effectively applied to other similar long-distance open channel water transmission projects.