| 崩塌体水力输移与塌岸淤床交互影响试验 |
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| 引用本文： | 余明辉,郭晓.崩塌体水力输移与塌岸淤床交互影响试验[J].水科学进展,2014,25(5):677-683. |
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| 作者姓名： | 余明辉 郭晓 |
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| 作者单位： | 1.武汉大学水资源与水电工程科学国家重点实验室, 湖北武汉 430072; |
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| 基金项目： | 国家自然科学基金资助项目(51339001;11272240)~~ |
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| 摘 要： | 以二元结构河岸崩塌模式为研究背景，在弯道水槽中展开系列试验，研究凹岸坡脚处成型崩塌体在水力作用下输移过程及其对岸坡稳定性与河床冲淤的交互影响。试验成果表明，崩塌体经水力分解破碎呈块状、片状或颗粒状起动，部分随水流带至凸岸或下游，堆积在坡脚附近的崩塌体残留量随水力作用大小及土体特性不同而变化。崩塌体临水面周围尤其上下游端水流紊动强烈易形成较大剪切力区，临坡面上下游端附近剪切力较无崩塌体时减小；崩塌体体积越大，对剪切力区特征的改变也越明显。崩塌体的存在虽不能制止附近岸坡的再次崩塌，但可能抑制崩岸发展及附近河床淤积的程度，崩塌体的粘性或体积越大，这种抑制作用越显著；相同崩塌体抑制附近河床淤积的程度较抑制岸坡崩塌的程度大。
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| 关 键 词： | 岸坡崩塌体 水力输移 河床演变 水槽试验 二元结构河岸 |
| 收稿时间： | 2013-09-06 |
Experimental study on the interaction between the hydraulic transport of failed bank soil and near-bank bed evolution |
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| YU Minghui,GUO Xiao.Experimental study on the interaction between the hydraulic transport of failed bank soil and near-bank bed evolution[J].Advances in Water Science,2014,25(5):677-683. |
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| Authors: | YU Minghui GUO Xiao |
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| Institution: | 1.State Key Laboratory of Water Resources and Hydropower Engineering Sciences, Wuhan University, Wuhan 430072, China;2.Three Gorges Cascade Dispatch & Communication Center of China Yangtze Power CO., Ltd, Yichang 443133, China |
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| Abstract: | Bank failure is a typical process of lateral channel migration. As a huge sediment source, failed bank soil may directly cause the increase of sediment concentration and considerable channel evolution in a short time. Based on the failure mode of composite river bank, a series of experimental tests in flume was conducted to investigate the processes of disintegration and transportation of a failed bank block at the toe of concave bank, and the interaction between the failed soil, bank stability and bed evolution. Experimental results indicate that a part of disintegrated bank block will be transported to convex bank or downstream, and the amount of the residual part depends on the hydraulic scour force and the properties of bank material. Larger flow shear stresses occur in a local near-bank zone with violent turbulence and higher velocity, especially around the failed block. The shear stress at the near-bank end of the failed block is smaller, as compared with the condition without failed block. The larger the size of the failed block is, the greater the influence on shear stress is. Although the failed block cannot prevent the non-cohesive bank soil from collapsing, the processes of bank failure and bed deposition can be reduced. This reduction is more obvious for a larger failed cohesive bank block. Furthermore, the reduction degree in the rate of bed deposition caused by the failed bank block is much higher than that of the occurrence of bank failure. |
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| Keywords: | failed bank soil hydraulic transport bed evolution flume experiment composite bank |
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