The probability distribution of the fluctuating velocity in three dimensions and the near-bed shear stress (NBSS) of a channel with a deposit body were studied using mathematical statistics and the turbulent kinetic energy method, respectively. This analysis of the longitudinal and plane distributions of the NBSS under varying discharges, width ratios and lateral slopes will help further understanding of the laws of sediment incipient motion and transport in channels. It was found that the probability distribution of the near-bed vertical fluctuating velocity was closer to a normal distribution than that in the longitudinal and transversal directions. The NBSS did not change much in the upstream sections of the deposit body, but the difference between the left bank (near the deposit body) and the right bank (far away from the deposit body) was obvious in the sections near the deposit body and downstream. A high shear stress area was located in the transition zone between the main flow and the backflow. Introducing the backwater parameter β, an exponential relationship between the relative NBSS and β was determined, which will help in quick estimates of the NBSS in future practical projects.

中文翻译：

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沉积体对近床剪应力的影响

采用数理统计和湍流动能法分别研究了含沉积体河道的三维脉动速度概率分布和近床剪应力(NBSS)。分析不同流量、宽度比和横向坡度下的 NBSS 的纵向和平面分布，将有助于进一步了解河道中沉积物初始运动和输送的规律。发现近床垂向脉动速度的概率分布比纵向和横向更接近正态分布。NBSS在存款主体的上游部分没有太大变化，但左岸（靠近矿体）和右岸（远离矿体）的区别在靠近矿体和下游的地段明显。主流和回流之间的过渡区位于高剪应力区。引入回水参数β ，确定了相对 NBSS 与β之间的指数关系，这将有助于在未来的实际项目中快速估算 NBSS。