中国铁道科学2017，Vol.38Issue(4)：33-39,7.DOI:10.3969/j.issn.1001-4632.2017.04.05
底坎对减缓采沙河床桥墩冲刷的效果及机理研究
Study on Effect and Mechanism of Pier Scour Mitigation by Sill in Riverbed with Sand Excavation
摘要
Abstract
Concerning about the issues of pier scour induced by sand excavation in riverbed,hydraulic analysis and flume experiments were conducted to study the effect of sill setting on the scour mitigation of upstream pier.The variation of flow turbulence structure was measured by particle image velocimetry technology to explore the correlation between sill scale,the redistribution of water flow and the efficiency of pier scour mitigation.Results indicate that under the same flow condition,the efficiency of pier scour mitigation varies with the sill height above riverbed and the distance between the sill and pier.The efficiency of pier scour mitigation decreases with the increase of inflow intensity.Within experiment range,if the ratio of sill height and water depth is equal to 1/5～1/3 and the sill is located downstream of the pier with a space of 1 ～ 1.5 times of pier diameter,the scour mitigation effect on pier is the best and the efficiency of pier scour mitigation is up to 20～30％.The scour mitigation mechanism by bed sill is to decrease turbulence intensity,shear stress and turbulence vorticity of water flow,and to reduce the sediment transport capacity of water flow,so as to realize pier protection.关键词
桥墩冲刷/采沙河床/底坎/紊流强度/桥墩防护Key words
Pier scour/Sand excavation on riverbed/Bed sill/Turbulence intensity/Pier protection分类
交通工程引用本文复制引用
齐梅兰,杨熠琳,郐艳荣..底坎对减缓采沙河床桥墩冲刷的效果及机理研究[J].中国铁道科学,2017,38(4):33-39,7.基金项目
国家自然科学基金资助项目(51578062) （51578062）
中国铁路总公司科技研究开发计划项目(2014G009-H) （2014G009-H）
