基于产汇流与洪泛模型的下穿式高速公路积水分析与思考

Analysis and reflection on ponding of underpress expressway based on models of runoff flow and flood

为了查明北京2012年"7.21"暴雨中严重积水的京港澳高速南岗洼路段的致灾原因并提出解决对策,在分析当地水文情况的基础上建立了该地区的降雨—径流—洪泛—积水数学模型。分析和模拟结果表明,当日南岗洼路段积水主要源于外流域洪水泛滥,其次为本地区及路面涝水。但即使不考虑外流域洪水影响,该路段本身的防洪排水系统也无法在"7.21"暴雨中保障下洼路段安全。建议对于类似低洼地区的下穿式公路,其防洪排涝工程需统筹考虑外洪、内涝、自产流诸多因素的相互影响,采取阻蓄抽排多种手段保障安全。

To find out the pavement ponding reason of Beijin-Hongkong-Macao expressway Nangangwa section caused by storm on July 21th, 2012 and figure out measures, a rainfall-runoff-flooding-ponding mathematical model was established on the basis of analysis of the local hydrology. Analyse and simulation results showed that the main source of ponding water in Nangangwa section was flood from other catchment, then the waterlogging of local region and pavement. However, even there was no impact of flood from other catchment, the stagnant water drainage system in this section would still fail to keep expressway safe in the 7.21 rainstorm. It was suggested that for the similar underpress expressway in low-lying area, the flood control and drainage project might take into consideration of interaction of the factors of outside flood, inside logging, and runoff flow and multiple measures, such as flood prevention and flood storage and drainage, might be taken for security.