通过试验,系统研究了边墩下游各种糙率条件下的泥沙淤积特性,分析了泥沙淤积的发展过程和变化规律。泥沙主要在矢量流速小于0.1m/s的主流与回流区交界带淤积。试验初期泥沙的淤积速度很快,2.0h后淤积减缓,3.0h基本达到淤积平衡,淤积体的沙脊达到水面。在泥沙淤积大致平衡的条件下,得出了泥沙淤积厚度、淤积面积和淤积体积与水流阻力系数的回归关系,三者均随糙率的加大而增加。
The fluvial process downstream an abutment of 50cm wide under different bed roughness condition was observed by laboratory experiments.The measured data show that most of the sediment deposition is along the border belts of the circulation region,where the flow velocity is less than 0.1m/s.Sediment deposition is very quick at the initial stage of experiment,about two hours later it slows down,and about three hours later the deposition body is approximately in equilibrium.The experiment continues until or unless the deposition body tops the water surface.The regression relationships of the depth,area and volume of the sediment deposition with the coefficient of bed resistance are presented in this paper.It is found that all these three parameters increase with bed roughness.