透水性铺装地面的壤中流特征

人行道、步行街、自行车道、休闲广场和庭院等静负荷和动负荷较低、结构要求不高的硬化地面,改造为透水性铺装地面可以提高地表雨水下渗能力,减少地面积水,削减洪峰并延迟洪峰出现时间.利用人工模拟降雨试验,降雨均匀度超过80％,降雨强度分别为31.38、42.32、50.60、58.88、69.82、78.09 mm/h,对构筑的透水性铺装地面降雨入渗产流过程进行模拟研究.结果表明：在降雨历时60 min、降雨量小于78 mm的试验条件下,壤中流是透水性铺装地面总径流的主要组成形式,透水性铺装地面壤中流占总降雨量的比例随降雨强度的增大而增大,透水性铺装地面的铺设是导致地面壤中流发生和发展的主要原因.研究结果可为基于透水性铺装地面的雨水利用提供参考.

Characteristics of subsurface flow in porous pavement

Impervious surfaces have since a long time been held responsible for the destruction of watershed integrity in urban and urbanizing areas as cites are being covered by airtight concrete surfaces like roads and buildings. In order to improve surface infiltration capacity, it is necessary to transform hardened grounds like sidewalks, bicycle tracks, leisure squares and courtyards to porous pavements. For studying the runoff characteristics of porous pavements, a series of simulated rainfall experiments under different rainfall intensities （31.38,42. 32,50.60,58.88,69.82, and 78.09 mm/h） were conducted. The runoff generation process and the percentages of the subsurface runoff as part of the total precipitation are discussed in this paper. The results show that subsurface flow is the dominant runoff generation process. The percentages of the subsurface runoff vary with different rainfall intensities. Under the same pavement type, the ratio of the subsurface runoff to the total precipitation increases with an increase in the rainfall intensity. The infiltration capacity of the underlying surface of a city will be improved by increasing the proportion of permeable bricks and porous concrete block with a lower sand proportion.