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河岸崩塌是河道横向变形的重要表现形式,崩塌体作为陡增的泥沙源反作用于河床演变,进一步影响岸坡的二次崩塌。在弯道水槽中展开系列试验,研究水力作用下非黏性及黏性均质岸坡冲刷崩塌力学机理、塌岸淤床交互作用过程及其影响因素。试验表明,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,并在河床上分解、输移掺混中交互作用的反复循环过程。岸坡崩塌、崩塌体与河床发生掺混最剧烈处位于弯道出口水流顶冲点附近,非黏性岸坡崩塌更容易发生在水面附近较浅的地方,而黏性岸坡崩塌更倾向于在坡脚附近较深的地方发生。近岸流速及河床可动程度越大,岸坡总冲刷坍塌量也越大,对于非黏性土其岸坡崩塌体在河床上的总淤积量也越大。研究成果初步揭示了塌岸与河床冲淤的交互作用模式,为进一步深入的研究奠定了基础。
River bank collapse is an important manifestation of the lateral deformation of the river course. The collapse body as a sharp increase of sediment source reaction to the riverbed evolution, further affecting the second collapse of the bank. A series of tests were carried out in a curved flume to study the mechanism of collapse and collapse mechanics of non-viscous and viscous homogeneous slope under hydraulic stress, and the interaction process of sediment collapse and its influencing factors. Experiments show that the bank slope erosion during the process of water scouring is the process of water flow scouring the foot of bank slope, bank collapse and the foot of silting slope of collapse body, and decompose on the river bed and transfer the cyclic process of interaction during the mixing. Collapse of bank slope, collapse body and riverbed occurred most intensively at the corner exit flow top flushing point, non-viscous slope collapse more likely to occur in the shallow water near the surface, and viscous slope collapse is more inclined to Occurs deep in the foot of the slope. The greater the coastal flow rate and river bed movement, the greater the total erosion and collapse of the bank slope. For the non-cohesive soil, the total siltation of the bank collapse body in the bank slope is also larger. The research results reveal the interaction mode of bank collapse and riverbed scouring and sedimentation, which lays the foundation for further research.