2021年郑州“7·20”特大暴雨五龙口停车场内涝及地铁隧洞进水分析

Analysis of waterlogging in Wulongkou parking lot and subway tunnel flooding of"7·20"extreme rainstorm in Zhengzhou City in 2021

五龙口停车场位于郑州市贾鲁河流域的五龙口明沟排水片区,区内涝水主要通过五龙口明沟排泄。经过调查勘测与资料分析,停车场场区地势较周边道路及街区明显低洼,郑州“7·20”特大暴雨过程场区积水主要为停车场场区及明渠起点上游汇水范围内涝水。研究构建了五龙口停车场内涝分析模型,由五龙口明沟排水范围地表二维水动力模型、五龙口明沟的河道一维水动力模型以及隧洞进水模型构成,并利用郑州“7·20”水灾调查结果对模型进行了合理性分析。为全面分析五龙口停车场挡墙倒塌、五龙口明沟西侧堆土与明渠起点盖板对五龙口停车场及周边积水、地铁隧洞进水影响,研究利用五龙口停车场内涝分析模型对4种工况情景展开模拟分析,分析结果表明,若五龙口明沟明渠起点附近不存在临时堆土、盖板,五龙口停车场挡墙不发生倒塌,环保路与蓝天路交汇口最大积水深度可降低0.35 cm,五龙口停车场进出场地铁隧洞的最大进水流量可减少约50%,进水总量可减少约60%。

Wulongkou parking lot is located in the drainage area of Wulongkou open ditch of Jialu River Basin in Zhengzhou City,and the waterlogged water of the drainage area is mainly discharged through Wulongkou open ditch.After field investigation and data analysis,the terrain of Wulongkou parking lot is significantly lower than the surrounding roads and blocks.The ponding of the parking lot area in the"7·20"heavy rainstorm is mainly from the parking lot area and the upstream catchment area of the starting point of the open ditch.The waterlogging analysis model of Wulongkou parking lot is constructed,which is composed of 2D surface hydrodynamic model of Wulongkou open ditch drainage range,1D hydrodynamic model of Wulongkou open ditch and subway tunnel flooding model.The rationality of the model is analyzed by using the"7·20"flood investigation results in Zhengzhou City.In order to analyze the impact of the collapse of the retaining wall of Wulongkou parking lot,the soil pile on the west side of Wulongkou open ditch and the starting cover plate of the open channel on the waterlogging in Wulongkou parking lot and its surroundings and the subway tunnel flooding,the waterlogging analysis model of Wulongkou parking lot is used to simulate and analyze four calculation scenarios.The calculation results show that if there is no temporary soil pile and cover plate near the starting point of Wulongkou open ditch,and the retaining wall of Wulongkou parking lot does not collapse,the maximum ponding depth at the intersection of Huanbao road and Lantian road can be reduced by 0.35 cm.The maximum inflow of the subway tunnel entering and leaving of the Wulongkou parking lot can be reduced by some 50%,and the total inflow can be reduced by some 60%.