高架快速路雨水径流近零排放控制目标研究

Study on Zero Discharge Target of Rainwater Runoff in Elevated Expressway

摘要:

针对年径流总量控制率一般仅解决小雨水平径流的问题，为提高道路雨水渗蓄量，降低市政管网进水量，以无锡高架快速路为研究对象，分别计算了不同横断面类型和0.5~5 a一遇降雨条件下，中分带、侧分带和人行道绿化带实现雨水径流零排放所需的海绵设施量。分析得到：对于大于等于6 m宽的中分带，通过设置生物滞留带可达到5 a一遇零排放；对于2.5 m宽侧分带，组合设置下凹式绿地和生物滞留带时可达到5 a一遇零排放，但每公里建设费用最大需要增加158 万元；对于2 m宽绿化带，如果仅设置生态树池或下凹式绿地，难以达到零排放，为实现5 a一遇零排放，最大需要利用红线外7.5 m宽绿地。最后，综合提出了无锡市各类型高架快速路的推荐雨水径流近零排放控制目标，为海绵城市建设升级提供参考依据。

Abstract:

The total annual runoff control rate generally only solves the problem of horizontal runoff of light rain. In order to improve the road rainwater infiltration and reduce the inflow of municipal pipe networks, taking the elevated expressways in Wuxi as the research object, the amount of sponge facilities required to achieve the zero discharge of rainwater runoff in the central median, lateral zoning and sidewalk green belt under the different cross-sectional types and 0.5~5 a rainfall conditions once are calculated. The analysis shows that for the central median with a width greater than or equal to 6 m, the 5 a zero discharge once can be achieved by setting up the biological retention zones. For the lateral zoning with a width 2.5 m, the 5 a zero discharge once can be achieved by setting up the combination of concave green space and biological retention zone. But the maximum construction cost per kilometer needs to increase by 1.58 million yuan. For the 2 m wide sidewalk green belt, it is hard to achieve the zero discharge if only setting up the ecological tree pools or concave green space. In order to achieve the 5 a zero discharge once, a 7.5 m wide green space outside the red line needs to be utilized. Finally, the recommended zero discharge control targets for rainwater runoff on various types of elevated expressways in Wuxi are comprehensively proposed, which provides a reference for the upgrading of sponge city construction.