明渠砂质床面桩柱冲刷与导流防护试验研究Experimental study on scouring around pile-column in sand-bed of open channel and relevant flow guiding protection measure
黄雄合,许栋,及春宁,白玉川,刘洪昌
摘要(Abstract)：
为了研究明渠砂质床面桩柱冲刷的水沙动力机理,分析极限平衡冲刷深度和范围随水流雷诺数的变化规律以及抗冲刷导流防护措施的效果,利用动床模型水槽试验,再现了桩柱周围局部床面从平整发展到冲刷坑的发育过程,测量了各工况下冲刷坑的形态参数,并利用PIV技术观测粗颗粒泥沙局部悬扬运动。结果表明:桩柱冲刷范围(相对于桩径D)随雷诺数ReD增大呈减小趋势。当雷诺数ReD在4 500~18 000之间变化时,冲刷深度变化范围为2.4D~1.3D,冲刷坑半径变化范围为4.5D~2.5D。砂质床面桩柱冲刷除存在显著的推移质运动外,还存在局部粗泥沙颗粒悬扬,且悬扬输沙的范围和强度随冲刷坑发展而强烈变化。在桩柱后方设置导流板能够有效抑制柱后卡门涡街的生成,桩后冲刷深度最大减小幅度为27.7%,但对柱前冲刷深度的影响不大。
关键词(KeyWords)： 桩柱;局部冲刷;水槽试验;推移质;输沙模式;泥沙悬扬;卡门涡街;泥沙冲淤平衡
基金项目(Foundation): 国家自然科学基金创新研究群体项目(51621092);国家自然科学基金项目(51579175,51779172);; 天津市科技支撑计划项目(16ZXCXSF00020)
作者(Author): 黄雄合,许栋,及春宁,白玉川,刘洪昌
DOI: 10.13928/j.cnki.wrahe.2017.11.022
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