连续急弯对河段输沙能力的累积效应试验研究.

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. [ABSTRACT FROM AUTHOR]