连续急弯对河段输沙能力的累积效应试验研究  

Experimental Study on Cumulative Effect of Continuous Sharp Bends on Sediment Transport Capacity of River Section

作　　者：吴岳昆 孙一[2] 侯志军[2] 伊晓燕[2] WU Yuekun;SUN Yi;HOU Zhijun;YI Xiaoyan(Zhengzhou University,Zhengzhou 450001,China;Yellow River Institute of Hydraulic Research,YRCC,Zhengzhou 450003,China)

机构地区：[1]郑州大学,河南郑州450001 [2]黄河水利委员会黄河水利科学研究院,河南郑州450003

出　　处：《人民黄河》2023年第2期28-32,37,共6页Yellow River

基　　金：国家自然科学基金资助项目(51809107);中央级公益性科研院所基本科研业务费专项(HKY-JBYW-2020-10);国家重点研发计划项目(2018YFC0407801)。

摘　　要：连续急弯在天然河道中广泛存在,研究其水沙运动规律,对急弯河段河道整治及灾害防治具有重要的指导意义。针对黄河下游连续急弯河段,以非恒定流动床物理模型试验为基础,探讨了连续急弯对河段输沙能力的累积效应,结果表明:连续急弯造成额外的能量损失,在特定水沙条件下导致河道整体上呈淤积状态;连续急弯河段输沙能力沿程减弱,整体上呈现出流量越大输沙能力减弱幅度越大的特征;急弯的平面几何特征可用中心角(θ)和曲率半径与河宽之比(rc/B)的乘积表示;涨水阶段,弯道平面几何特征与输沙能力负相关;退水阶段,当漫滩流量接近平滩流量时,输沙能力在局部弯道稍有恢复,水流归槽后,弯道平面几何特征与输沙能力又恢复为负相关关系。Continuous sharp bends exist widely in natural rivers. Studying the law of water and sediment movement has important guiding significance for the regulation and disaster prevention of sharp bends. Based on the movable bed physical model test of unsteady flow bed, this paper discussed the cumulative effect of continuous sharp bends on sediment transport capacity of the lower Yellow River reach. The results show that the continuous sharp bends cause additional energy loss, which leads to the overall deposition of the river channel under specific water and sediment conditions. The sediment transport capacity of the continuous sharp bend sections declines along the river and presents a characteristic of the greater the discharge, the greater the reduction of sediment transport capacity. The horizontal geometric characteristics of sharp bends can be expressed by the product of the ratio of center angle and curvature radius to river width. In the flood stage, the cumulative effect of continuous bends on sediment transport capacity is that the horizontal geometric characteristics of sharp bends are negatively correlated with sediment transport capacity. In the recession stage, when the floodplain discharge is close to the bankfull discharge, the sediment transport capacity slightly recovers in local bends, and after the flow returns to the channel, the horizontal geometric characteristics of the bends and the sediment transport capacity return to a negative correlation again.

关 键 词：连续急弯 输沙能力 累积效应 动床模型 黄河下游 

分 类 号：TV131.2[水利工程—水力学及河流动力学] TV882.1