长江上游卵石输移运动规律研究及数值模拟*

基于长江上游东溪口卵石滩段的物理模型,开展了典型系列年卵石输移特征的试验。根据不同水动力条件下卵石输移的实测数据,从动力机理出发确定砾石输移速度。以此为基础,改进了二维数值模型,并将其应用于东溪口河段卵石输移过程模拟。将计算的卵石输沙分布及泥沙冲淤过程与实测值进行对比,卵石走沙轨迹与河道内走沙基本吻合,模拟泥沙冲淤变化与该河段实测分布一致。说明改进后的平面二维卵石推移质运动模型能较为真实地反映河道内卵石输移特性,可为解决长江上游卵石河段泥沙问题与航道整治工程提供理论与数据支撑。

Research and numerical simulation of mechanism of gravel transport in upstream of the Yangtze River

Based on the physical model of the Dongxikou gravel beach in the upstream of the Yangtze River,a series of experiment on the characteristics of annual gravel transport were conducted.According to the measured data of the gravel transport under different hydrodynamic conditions,the velocity of the gravel is established from the dynamic mechanism.The 2D numerical model is improved considering the above research results,and then applied to simulate the process of the gravel transport in the Dongxikou gravel beach.The calculated distribution of gravel transport and the process of sediment scouring and silting are compared with the measured values,and the track of gravel walking is basically consistent with the sand walking in the channel.It is shown that the improved two-dimensional gravel model can reflect the characteristics of gravel transport in the river,and can provide theoretical and data support for solving the sediment problem in the upstream of the Yangtze River and waterway regulation project.