陡坡排水管道防洪模拟及潮位效应耦合分析OA

Under the condition of rainstorms,the operation safety of the urban drainage pipe network system is faced with severe challenges.Especially,under the coupling influence of pipe slope and external tide level of the drainage outlet,backflow are very easy to occur,which poses a threat to the safety of the pipeline structure and significantly weakens the overall drainage capacity of the city.To investigate the complex dynamic response mechanism of water flow inside the drainage network,this paper established a mathematical model based on the one-dimensional Saint Venant equation system.The model could accurately simulate the water flow process inside the branch pipe network under the combined action of simulated slope and tide level,including the spatiotemporal variation characteristics of flow rate,flow velocity,and water level.On this basis,based on the actual project of"high water and high drainage"in Jiangbei urban area of Fuzhou City,a complete hydrodynamic coupling model was constructed to quantitatively analyze the flood drainage efficiency and operation status of the project system under different tide level conditions and rainfall intensity combination conditions under the set rainstorm scenario,so as to assess its ability to cope with extreme rainstorm flood risk.The results show that the numerical model built in this paper successfully reproduces the hydraulic characteristics of open flow and full flow and the backwater effect of the pipeline in the large-slope hydraulic simulation and slope-based backwater effect of tide coupled hydraulic simulation,and the simulation results do not show numerical oscillation,indicating that the model can be used to simulate the internal flow change process of the drainage network under the slope tide level coupling effect.At the same time,the dynamic water pressure and total head of each main branch junction node decrease along the way under the 50-year return period rainstorm condition of the above project.Bayi Reservoir can play a safety regulation role during the rainstorm,and the flow velocity and flow in the main pipe section meet the safety requirements for flood drainage.This study conducts a panoramic simulation diagnosis of the system through a model,which can accurately identify weak links and redundant capacity in the network,thereby tapping into the potential of existing facilities.The related results can provide a scientific basis for the planning and design of flood discharge projects and direct technical reference for the fine management and optimized operation of existing urban flood discharge systems.