滑坡堵江弯道床沙分选及河床变形试验研究

Experimental Study on Bed Material Sorting and Channel Deformation Under Landslide Damming

为了对地震后弯曲河流的灾害防治提供科学依据,通过弯道不同水流条件清水冲刷试验,分析了弯道水流结构、床沙分选及其河床变形特征,得到结论:弯道进口顶冲位置具有较大的横向流速;对于非均匀床沙弯道,河段不同位置床沙粗细化现象极为显著;弯道河段地形冲淤变化不同区域存在较大的差异。深入揭示了弯道底沙运动、冲淤变形与水流特性的相互作用机制。

In order to provide experimental basis for the reconstruction of river bend after the earthquake,a series of clear-water scour with the same initial bed material were done in a U-shape bend.The variations of flow structure,sediment sorting coefficients and bed deformations were analyzed.The results showed that,there was large transverse velocity at the blunt position of the bend＇s inlet,bed sediment sorting was remarkable for non-uniform bed sand,and bed deformations had a large difference in different domains which were favorable to further understand the interactions among flow structure,sediment movement and channel deformation in bends.