冲刷过程中岸坡条件对塌岸淤床交互作用影响的试验研究

在弯道水槽中开展系列试验，研究不同的岸坡条件对岸坡稳定性以及崩塌体与河床交换作用所产生的影响。试验成果表明：岸坡崩塌及崩塌体的分解输移与近岸水流的紊动能关系密切。水流冲刷过程中岸坡破坏是水流淘刷岸坡坡脚、岸坡崩塌及崩塌体淤积坡脚并在河床上输移的反复循环过程。无论岸坡是黏性土组成还是非黏性土组成，坡脚附近河床并没有与崩塌土体发生掺混。在岸坡形态、河床组成及水力条件相同的情况下，黏性岸坡坡脚处河床冲刷量明显大于非黏性岸坡坡脚处河床冲刷量；黏性岸坡崩塌量小于非黏性岸坡崩塌量。在岸坡材料相近、河床组成及水力条件相同的情况下，较陡岸坡经水流淘刷后更易失稳，岸坡冲刷坍塌量及崩塌物质在河床上的淤积量明显大于较缓岸坡情况。

Experimental Study of the Influence of Bank Conditions on Bank Failure and Interaction with Riverbed Deformation During Scouring Process

A series of experiments were carried out in a bend flume to study the influence of different bank conditions on bank stability and the interaction between the failed substances and bed evolution. Experiment results indicate that bank erosion, the disintegration and transportation of a failed bank block and the mixing between the failed soil and bed evolution have close relations with the turbulent energy near the bank. Bank erosion is a process of repeated interaction between bank toe scouring and bank collapse along with the deposition and transportation of landslide material. Whether the bank material is cohesive or not, there is no mixing between riverbed near bank toe and failed bank block. With the same bank configuration and riverbed compositions and hydraulic conditions, riverbed scouring volume near the cohesive bank toe is larger than the one near the non-cohesive bank. The erosion volume of cohesive bank is smaller than that of the non-cohesive bank. With similar bank material and the same riverbed compositions and hydraulic conditions, steeper bank is prone to greater instability under water scouring. The erosion volume of steeper bank and the silting volume of failed block on the riverbed are larger than that of the bank with slower slope.