清水条件下桥墩局部冲刷坑底部粗化效应研究  

Research on Coarsening Effect of Local Scour Pit Bottom on Bridge Piers Under Clear Water Conditions

作　　者：武煜伦 吴龙华[1] 杨校礼[1] 方陈卓 WU Yu-lun;WU Long-hua;YANG Xiao-li;FANG Chen-zhuo(College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水利水电学院,江苏南京210098

出　　处：《水电能源科学》2023年第12期125-128,141,共5页Water Resources and Power

摘　　要：在非均匀沙河床上,桥墩局部冲刷坑底部粗化覆盖层会影响到桥墩的最大局部冲刷深度。通过水槽试验研究分析了单层非均匀沙河床上桥墩局部冲刷坑底部粗化覆盖层的级配、相对粗化度和不均匀程度。结果表明,粗化覆盖层中泥沙的中值粒径随桥墩局部冲刷深度的增加而增加,其相对粗化度随来流弗劳德数的增加而增加,而不均匀程度则随来流弗劳德数的增加而减小。并在此基础上提出了桥墩局部冲刷坑底部粗化覆盖层泥沙的级配计算公式,并利用实测资料验证了该公式具有良好的适用性和可靠性。On the non-uniform sand river bed,the armor layer at the bottom of the bridge pier local scour pit will affect the maximum local scour depth of the bridge pier.Through a flume model experiment,the sediment gradation,relative coarseness,and non-uniformity of the armor layer at the bottom of the local scour pit on the bridge pier were studied.The results indicate that the median particle size of the sediment in the armor layer at the bottom of the local scour pit on the bridge pier increases with the increase of the local scour depth on the bridge pier,and its relative coarsening degree increases with the increase of the Froude number,while the degree of non-uniformity decreases with the increase of the Froude number.A formula for calculating sediment particle grading in the armor layer at the bottom of the local scour pit on the bridge pier has been proposed.The applicability and reliability of the proposed formula is verifies by the measured data.

关 键 词：桥墩 最大局部冲刷深度 粗化覆盖层 泥沙颗粒级配 相对粗化度 不均匀程度 

分 类 号：TV142[水利工程—水力学及河流动力学]