山区河流卵石推移质强冲刷输移特性试验研究

【作者】 王愈；

【导师】 范北林；

【作者基本信息】 长江科学院 ， 水力学及河流动力学， 2009， 硕士

【摘要】 本文首先论述了山区河流卵石推移质的国内外研究现状,并选取了屏山至重庆河段为典型的山区河段,分析了山区河流的地质构造、河床特征、河床边界条件、床沙组成及其形成原因。其次,在对卵石床沙推移质输沙率研究现状分析的基础上,选用基本上能符合山区河流卵石河床的天然试验沙,通过清水强冲刷实验,对卵石河床在清水强冲刷条件下输移的规律及形成机理进行了分析。在已有的研究成果的基础上,探索了考虑卵石形状和隐暴作用的输沙率公式,利用试验实测资料,对所推求的输沙率公式进行了回归分析,确定了有关参数。该公式能充分反映山区河流卵石床沙的形状及级配对输沙率的影响。并探讨了山区河流卵石推移质强冲刷的粗化问题,初步分析了粗化过程的规律及粗化后床沙级配的变化规律。最后,研究了山区河流卵石推移质强冲刷时,水流结构的分布特性,并探讨了水流横对面流速分布及水流相对脉动强度变化的规律。更多还原

【Abstract】 In this paper the status quo at home or abroad of gravel bedload on mountain river had been discussed first. Take the reach from Pingshan to Chongqing as an example, the geological structure、characteristic of riverbed、boundary condition of riverbed、the composition of sediment and the corresponding form reason had been discussed.Then, the bedload transport rate of gravel bed had been learned. Choose the reasonable nature experimental sediment of gravel bed on mountain river, and take the strong scour experiment. Based upon this experiment, the mechanics of sediment transport had been analysis. Considering the shape of gravel bed and hiding and exposing action, moreover, the sediment transport rate equation had been set. At last, the equation had been systematical analysis and defined the parameters with the method of regression analysis. The equation can reflect the effect of gravel profile and gradient on sediment transport rate. And the strong scour had been discussed. The law of coarsening process and gradient had been analysis preliminary.At last, under the condition of strong scour of gravel bed of mountain river, the distribution characteristics of flow structure and the velocity distribution of cross section and the law of turbulence intensity of flow had been studied.更多还原