工程堆积体陡坡坡面径流水动力学特性

Hydro-dynamic Characteristics of Steep Slope Runoff of Engineering Accumulation Under Simulated Runoff Conditions

通过野外放水试验,对高速公路沿线典型堆积体陡坡(36°)在模拟径流冲刷条件下的坡面径流水动力学特性进行了研究,结果表明,平均流速与径流深均随流量的增加呈幂函数增加,不同坡面径流状态下(薄层水流和细沟流)流量的指数不同,且各自与室内研究结果有所差异;不同坡段的平均流速随坡长增加呈"S"形曲线变化。堆积体陡坡坡面径流属急流范畴,由过渡流向紊流转变的临界放水流量在20～25L/min之间。Darcy-Weisbach阻力系数(f)与径流雷诺数(Re)之间存在幂函数正相关关系,与弗罗德数(Fr)之间存在幂函数负相关关系,不同坡段的平均阻力系数与坡长呈双曲线函数关系。

A set of field pouring water scouring experiments were carried out to investigate the hydro-dynamic characteristics of slope runoff in steep slope(36°)on typical engineering accumulation along the line of'shenfu' freeway.The results showed that the relationship between average flow velocity and flow depth could be well described by apower function of flow discharge.The exponent of flow discharge differs under different flow states(sheet and rill).Average flow velocity of different slope segments showed'S'curve trend with the increase of slope length.The flow regime of slope flow belonged to the supercritical flow condition.The critical discharge controlling the transformation of flow regime from transition to turbulence was between 20 L/min and 25L/min.There were power positive correlation between Darcy-Weisbach resistance coefficient(f)and Reynolds number(Re),and power negative correlation and frode munber(Fr).Average resistance coefficient of different slope sections could be described as a hyperbolic function of slope length.