孤立波作用下单排桩附近床面冲刷实验研究  

Laboratory study on seabed scour around a single row of piles under solitary waves

作　　者：张壮壮 姚宇 许从昊[2] ZHANG Zhuang-zhuang;YAO Yu;XU Cong-hao(Hunan Provincial Key Laboratory of Key Technology on Hydropower Development, Changsha 410014, China;School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha 410114, China)

机构地区：[1]水能资源利用关键技术湖南省重点实验室,长沙410014 [2]长沙理工大学水利工程学院,长沙410114

出　　处：《水道港口》2021年第4期457-463,共7页Journal of Waterway and Harbor

基　　金：湖南省科技计划项目(2017RS3035);水能资源利用关键技术湖南省重点实验室开放研究基金项目(PKLHD201706)。

摘　　要：为揭示海啸波冲击下桩式防波堤的桩基附近泥沙冲刷特性,文章通过物理模型实验研究了孤立波作用下单排桩柱结构附近床面的局部冲刷问题,测试了入射波高和水深对冲刷坑形态发展的影响。结果表明:床面冲刷主要发生在相邻柱体的间隙处;在冲刷过程的前期阶段,排桩不同间隙附近床面冲刷的演变存在一定的差异;到冲刷后期,各间隙床面三维形态上的差异逐渐消失;达到冲刷平衡后,在间隙附近形成显著的冲刷坑,冲刷坑的下游则出现淤积的沙坝;沿间隙中心线剖面上的最大冲刷深度出现在柱中心偏下游位置,最大淤积高度出现在柱中心下游的几倍圆柱直径范围内。冲刷坑沿槽宽方向的发展随着波高的增大而增大,随着水深的增大变化不明显;平衡剖面上最大冲刷深度、最大淤积高度和冲刷坑水平长度亦随着波高的增大而显著增加。试验成果可为进一步建立相应的三维泥沙冲刷数值模型提供校核依据。It is reported in this paper an experimental study on the local scour of seabed around a single row of piles subjected to solitary waves.Solitary waves of varying water depth and wave height were used in the experiments and high-resolution three-dimensional scour profiles are sampled after a given number of solitary waves.The effects of both incident wave height and water depth on the evolution of scour profile were examined.The results show that most seabed scour occurs around the gap between adjacent piles.The evolution of scoured seabed varies around different gaps at the initial stage of the scouring process,but such three-dimensional discrepancy in the seabed morphology disappears eventually at the final stage.When the status of equilibrium scour is reached,visible scour pits form around the gaps while accreted sand bars appear downstream of the pits.For the seabed profile along the centerline of gap,the largest scour depth was found downstream closer to the pile center,while the largest accretion height was located within several diameter of the pile away downstream of the pile.The lateral dimension of scour pit grows with the increasing wave height,but it does not change significantly with the increasing water depth.The maximum scour depth,maximum accretion height and cross-shore width of the pit also increase with the increase of wave height,and the water depth seems to have little effect on them compared to the wave height.The result of the present research could also serve as a source of calibration for the development of relevant three-dimensional numerical models for sediment scour under wave condition.

关 键 词：孤立波 单排桩柱 桩基冲刷 三维床面地形 冲淤平衡 冲刷深度 

分 类 号：U656.2[交通运输工程—港口、海岸及近海工程]