不同降雨条件下城市下垫面表面薄层水流的典型参数试验研究

以北京昌平未来科技城试验基地的降雨强度为降雨条件,通过室内降雨试验平台,研究了4种典型不透水下垫面(沥青、砼面、SBS改性沥青和砼方砖)和4种典型透水下垫面(草坪砖A、草坪砖B、风积砂砖A和风积砂砖B)分别在8种恒定雨强条件下形成薄层产流后的糙率系数、沿程阻力系数和径流系数的变化过程。结果显示:平面尺寸、表面光滑度、材质对不透水下垫面的糙率和沿程阻力系数影响较为明显;而结构、材质对透水下垫面的糙率和沿程阻力系数影响较为明显;两类下垫面的糙率值和沿程阻力系数均随雨强增加呈现减小的变化趋势,但变化的幅度较小,之后逐渐趋于稳定;两类下垫面的径流系数在不同雨强下保持相对稳定。

Experimental study on typical parameters of thin layer flow of urban underlying surface under different rainfall conditions

Based on the rainfall intensity of the future science and technology city in Changping, Beijing, the experiments were taken through the indoor rainfall test platform. The changes of roughness coefficient, resistance coefficient and runoff coefficient of four typical impervious underlying surface (asphalt, concrete surface, SBS and concrete square brick) and four typical permeable underlying surface (lawn brick A, lawn brick B, aeolian sand brick A and aeolian sand brick B) were studied under eight kinds of constant rain intensity. The results show that the plane size, surface smoothness and material have obvious influence on the roughness and resistance coefficient of impervious underlying surface, while structure and material have obvious influence on the roughness and resistance coefficient of permeable underlying surface. The roughness value and resistance coefficient of these two types of underlying surface decrease with the increase of rain intensity. But the variation range is small, and then tends to be stable gradually. The runoff coefficient of these two types of underlying surface keeps relatively stable under different rainfall intensity.