基于SWMM耦合模型的道路行泄通道设计方法与应用

针对现有道路行泄通道的设计方法仅适用于道路单独排水、忽略道路明渠流与管道压力流之间水动力相互作用的问题,提出了一种基于SWMM构建道路明渠流与管道压力流耦合的水力排涝模型,来进行道路行泄通道设计以应对极端降雨事件的方法。并以某山地城市为例,构建SWMM雨水管道水力模型,进行50年一遇降雨情景下的内涝模拟,获得易涝点分布。在此基础上,根据内涝区域的竖向分析和水文分析,结合管道排水能力,设置道路行泄通道系统,构建水力耦合排涝模型。并利用耦合排涝模型优化行泄通道设计参数,对比不同方案下情景模拟结果,获得符合实际情况的行泄通道,最终确定行泄通道设计方案。案例分析表明,基于水力耦合排涝模型的道路行泄通道设计方法,考虑了道路明渠流与管道压力流之间水动力相互作用以及流量交换,反映了极端暴雨条件下道路与管道联合排涝系统的实际运行状态,使得行泄通道的设计更为系统、合理。

Design Method and Application of Roadway Drainage Path Based on Coupled Hydraulic SWMM Model

The existing design method of roadway drainage path is only applicable to separate drainage of road and neglects hydrodynamic interaction between open channel flow in the roadway and pressure flow in the underground drainage pipes. Therefore,a hydraulic drainage model of roadway open channel flow coupled with pipe pressure flow based on SWMM was proposed to design the roadway drainage path to cope with extreme rainfall events. In a case study in a mountain city,a hydraulic model of stormwater pipeline based on SWMM was constructed to simulate waterlogging in a 50-year rainfall scenario,and the distribution of waterlogging prone points was identified. On this basis,according to the vertical analysis and hydrologic analysis of waterlogging area and combined with the drainage capacity of the pipeline,the roadway drainage path system was set up to build the hydraulic coupled drainage model.The coupled drainage model was then used to optimize the design parameters of the drainage path,and the simulation results under different scenarios were compared to obtain the drainage path in line with the actual situation. Finally,a design scheme of the drainage path was determined. The case study indicated that the design of the roadway drainage path based on the coupled hydraulic model considered hydrodynamic interaction between open channel flow and pipeline pressure flow and their flow exchange,reflected the actual running state of the combined drainage system of road and pipeline under the condition of extreme heavy rain,which maked the design more systematic and reasonable.