道路生物滞留带径流削减效果的试验研究

道路积水是当前我国城市发展面临的突出问题,而设置生物滞留带是典型的道路雨水减排措施之一。为研究不同降雨强度和溢流高度条件下道路生物滞留带的径流削减效果和渗流规律,利用人工降雨装置和模拟道路-生物滞留带平台设计试验,并根据试验结论,结合实际案例进行水文效应计算,对道路生物滞留带设计提出优化建议。结果表明:试验条件下重现期P≤10年时,滞留带可延迟6～10 min的径流峰值时间;不同试验条件的径流削减率和峰值削减率分别为41%～100%和38%～100%;提升溢流高度对径流总量削减效果明显,并对渗流过程有较大影响;渗流流量与滞留带表面水头高度存在一定函数关系。基于试验结果,对道路-生物滞留带系统径流削减率公式进行了推导,为部分参数选取提供了参考值。

Experimental study on runoff reduction effect of road bio-retention zone

Ｒoad water-logging is a prominent problem during the urban development in China，while the arrangement of bio-retention zone is one of the typical road rainwater reduction measures as well. In order to study the runoff reduction effect and seepage law of road bio-retention zone under the conditions of various rainfall intensities and overflow heights，the experiment is designed with artificial rainfall device and simulated road bio-retention platform，and then the hydrologic effect is calculated in combination with the actual case concerned for proposing the relevant optimization suggestions on the design of the road bio-retention zone in accordance with the experimental conclusion. The result shows that under the experimental condition，when the return period is P≤10a，the time of the peak runoff can be delayed by 6 ～ 10 min with the bio-retention zone. The runoff reduction rate and the rate of the peak value are 41% ～ 100% and 38% ～ 100% respectively under different experiment conditions，while increasing the overflow height has an obvious effect on the reduction of the total runoff and a larger influence on the seepage process. A certain functional relation is there between the seepage flowrate and the height of the surface water head of the bio-retention zone. Based on the experimental result，runoff reduction rate formula of road bio-retention zone system is deduced，thus provides the relevant reference values for the selection of part of the parameters concerned.