从管道尾流区泥沙颗粒的受力平衡着手,探讨了管道冲刷的临界压力差。在此基础上,提出了一种防止或减少管道冲刷的新方法,即在管道下方安装柔性阻流器。通过物理模型试验,研究了单向恒定流及规则波作用下,柔性阻流器对管道两侧床面压力、冲刷深度的影响。试验结果表明:柔性阻流器的安装能明显减小管道两侧床面的压力差。在单向恒定流作用下,管道的冲刷深度随阻流器长度的增加而减小;当阻流器达到临界长度时,冲刷消失。规则波时,因阻流器的扰动作用,冲刷深度有所增加;但随阻流器长度的增加,其扰动作用减小,对床面的防护作用增加,因而冲刷深度减小。
The analysis of forces acting on the sand particle in the wake region of pipeline gives the critical pressure difference. Then, a new method to prevent or reduce the scouring is proposed. A flexible spoiler is placed between the seabed and pipelines, and its effect on the pressure along the bed and the scour depth are experimentally investigated. Experimental results show that flexible spoiler can significantly reduce the pressure difference between upstream and downstream bed. For the flow test, the scour depth decreases with the increasing of spoiler length. When the length reaches a critical value, the bed scour disappears. For the wave condition, the swing of flexible spoiler disturbs the sediment beneath the pipe which increases the scour depth. By increasing the spoiler length, the effect of disturbing decreases but the effect of protection increases, leading to the reduction of scour depth.