非均质河床双排桥墩局部冲刷数值模拟研究  

Numerical simulation for local scour around double-row bridge piers in uneven sandy riverbed

作　　者：段海澎 刘武[2] 朱大勇 魏松[2] 胡甜 DUAN Haipeng;LIU Wu;ZHU Dayong;WEI Song;HU Tian(Anhui Transportation Holding Group Co.,Ltd.,Hefei 230088,China;College of Citil Engineering,Hefei University of Technology,Hefei 230009,China;Zhejiang Unirersity Ningbo Institute of Teclmology,Ningbo 315000,China)

机构地区：[1]安徽省交通控股集团有限公司,安徽合肥230088 [2]合肥工业大学土木与水利工程学院,安徽合肥230009 [3]浙江大学宁波理工学院,浙江宁波317500

出　　处：《水资源与水工程学报》2020年第2期155-160,共6页Journal of Water Resources and Water Engineering

基　　金：国家自然科学基金项目(51709072);安徽省自然科学基金项目(1808085QE145);安徽交通控股集团科技项目(2017010650);国家级大学生创新创业训练计划项目(201810359029)。

摘　　要：精确模拟山区河流非均匀沙质河床桥墩的局部冲刷对桥梁设计和安全运行具有重要的意义。以黑石渡大桥河床床沙特征为背景,采用Flow3D软件开展非均匀沙质河床上双排圆柱形桥墩冲刷三维数值模拟研究。为考虑河床非均匀泥沙的悬移质运动、泥沙挟带、推移质输运等过程,在数值模拟过程中,根据非均匀沙质河床的颗粒分布曲线,对所筛取的各个级配范围内的颗粒采用其对应的中值粒径来表征。模拟得到了双柱排桥墩局部流场结构、河床的冲淤变化和上下游桥墩周围冲刷坑形态。研究表明:受桥墩阻水作用影响,墩前壅水、墩后跌水现象明显。墩周冲刷坑基本贯通整个墩周区域,受上游墩保护作用影响,下游墩冲刷坑的发育深度和规模小于上游墩。将数值模拟结果与试验结果进行了对比分析,二者吻合较好。研究成果可为深入开展非均匀沙质河床桥墩局部冲刷研究提供参考。Accurate simulation of the local scour around bridge piers in the rivers of mountainous area with uneven sandy riverbed is of great significance for the design and safe operation of the bridges.In this study,the Flow3D software was used to numerically simulate the scour around the double-row piers of Heishidu Bridge,which is built in uneven sandy riverbed.With the consideration of the suspended sediment movement process,sediment entrainment process and bed load transport process of uneven sediments in the riverbed,we marked the screened particles within each gradation range with their corresponding median particle sizes based on the particle distribution curve of the riverbed in the numerical simulation process.The obtained numerical results include detained flow field around the bridge piers,changes of riverbed scour and sedimentation,scour pits terrain morphology around the upstream and downstream piers.Under the influence of the water-blocking effect of the bridge piers,the phenomenon of water level rising in front of the piers and water level falling behind the piers can be clearly observed.Furthermore,scour pits are distributed all around the pier area,due to the protection effect of the upstream piers;the depth and scale of the pits around the downstream piers are smaller than those of the upstream piers.The numerical simulation results are in good agreement with the laboratorial test data,demonstrating the accuracy and effectiveness of the numerical calculation.The research results can contribute to the further research of local scour around bridge piers in uneven sandy riverbed.

关 键 词：双排桥墩 局部冲刷 数值模拟 非均匀沙质河床 

分 类 号：TV135[水利工程—水力学及河流动力学] U442.32[建筑科学—桥梁与隧道工程]