通过剖析地下空间与城市洪涝灾害环境的关系,确定影响地下空间洪涝灾害的关键因素为地形高程值、降雨强度、地表不透水率及泵站规模等,并对其进行单因素、双因素及三因素影响性分析。结果表明:地形高程和降雨是城市地下空间受洪涝灾害影响的决定性因素,选址处地形高程或设防高程应高于所在区域洪涝防御能力下的地形高程;地表积水深度和降雨频率呈幂函数分布特征,超过特征临界降雨频率,积水深度呈非线性指数级增长;积水深度和地表不透水率呈对数关系,透水率越小,积水影响范围越大;通过优化地下空间出入口选址和提高防御高程、排水系统改造及区域除涝能力提升可以降低内涝风险;通过韧性城市建设降低城市地表不透水率是应对降雨影响的重要途径,可减少降雨初期积水汇集速度;距防洪堤防较近的地下空间出入口应做好溃堤淹没的应对措施。

By analyzing the relationship between underground space and urban flood disaster environment, the key factors affecting underground space flood disasters are determined to be terrain elevation value, rainfall intensity, surface impermeability rate, and pump station scale, and single factor, double factor, and three factor impact analysis are conducted. The results indicate that: Terrain elevation and rainfall are the decisive factors affecting urban underground space under flood disasters. The terrain elevation or fortification elevation of the site should be higher than the terrain elevation under the flood defense capability of the area; The depth of surface water accumulation and the frequency of rainfall exhibit a power function distribution. Beyond the critical rainfall frequency, the depth of water accumulation increases nonlinearly exponentially; There is a logarithmic relationship between the depth of accumulated water and the surface impermeability rate. The smaller the permeability rate, the larger the impact range of accumulated water. By optimizing the selection of underground space entrances and exits, increasing defense elevations, renovating drainage systems, and enhancing regional flood control capabilities, the risk of waterlogging can be reduced; Reducing urban surface impermeability through resilient city construction is an important way to cope with the impact of rainfall, especially to reduce the speed of water accumulation in the early stages of rainfall; Measures should be taken to deal with the collapse and inundation of underground spaces near flood control embankments.