非黏性岸坡崩塌与河床冲淤的交互影响初步试验研究

Study on interaction between non-viscous bank collapse and river bed deformation

本文在弯道水槽中展开系列试验,研究非黏性泥沙颗粒组成的岸坡坍塌模式及其与河床冲淤的交互影响过程。试验结果表明,水流冲刷过程中河岸破坏是水流淘刷河岸坡脚、岸坡崩塌及崩塌体淤积坡脚并在河床上输移的交互作用反复循环过程。河岸崩退模式、速度以及稳定后的形态与近岸流速分布及河床边界条件等关系密切。近岸流速越大,稳定后的岸坡越趋平缓,崩塌体在河床上的淤积率越小;河床的可动性加剧了岸坡的崩退速度以及崩塌体在河床上的淤积率。

This paper presents a study on collapse patterns of non-viscous bank and its interaction with riverbed erosion and deposition through a series of experiments conducted in a bend flume. The experimental results reveal that bank destruction is a process of repeated interaction between bank foot scour and bank collapse along with the deposition and transportation of landslide material. The collapse process of bank and its stable forms are largely affected by riverbed boundary conditions and flow velocity distribution, particularly flow velocity near the bank. The faster the velocity near the bank is, the gentler the stable bank slope and the lower the deposition rate of landslide substances will become. Furthermore, movable riverbed increases the rates of bank erosion and collapsing objects deposition.