护圈厚度对圆柱桥墩局部冲刷防护效果的影响  

Influence of Collar Thickness on the Local Scour Reduction around the Cylindrical Bridge Pier

作　　者：吝哲峰 袁天刚 李家春[2] 仇荔斐 LIN Zhe-feng;YUAN Tian-gang;LI Jia-chun;QIU Li-fei(Shaanxi Nuclear Industry Engineering Survey Institute Co.,Ltd.,Xi′an 710054,Shaanxi Province,China;Key Laboratory for Special Area Highway Engineering of Ministry of Education,Chang′an University,Xi′an 710064,Shaanxi Province,China)

机构地区：[1]陕西核工业工程勘察院有限公司,陕西西安710054 [2]长安大学特殊地区公路工程教育部重点实验室,陕西西安710064

出　　处：《中国农村水利水电》2023年第10期9-14,共6页China Rural Water and Hydropower

基　　金：国家重点研发计划资助项目(2022YFC3002600)。

摘　　要：桥墩基础长期承受水流荷载的作用,极易产生基础周围的局部冲刷。桥墩基础局部冲刷是桥梁水毁的重要原因之一,严重影响桥梁的安全稳定运行,因此开展桥墩局部冲刷防护措施的研究显得尤为重要。护圈作为一种经典的防护措施,可有效减弱桥墩基础的局部冲刷。为了研究护圈厚度对桥墩局部冲刷防护效果的影响,基于数值模拟软件Flow-3D建立桥墩-水流-泥沙三维数值模型,采用Melville经典实验数据验证了模型的可靠性,并运用已验证的模型研究护圈厚度的改变对桥墩局部冲刷深度和桥墩局部冲刷坑形态的影响。结果表明:护圈对桥墩前后方的防护效果优于桥墩两侧,护圈厚度的增加会加剧桥墩周围的局部冲刷,尤其是桥墩两侧。在所选取的工况条件下,护圈厚度为0.05D(D为桥墩直径)时桥墩周围的局部冲刷深度最小,防护效果最好,此时防护效率可达54.4%。研究成果可为桥墩局部冲刷防护提供参考。Under the long-term effect of the flow load,the local scour around the bridge pier foundation is extremely prone to occur.Local scour of bridge pier foundation is one of the important factors of bridge failures,and seriously affects the safety and stability of bridges.Therefore,it is especially important to study the local scour reduction measures for bridge piers.As a classical scour reduction measure,the collar can effectively weaken the local scour around the bridge pier foundation.In order to study the local scour reduction around cylindrical bridge piers affected by the collar thickness,a three-dimensional numerical model of pier-flow-sediment is established based on the numerical simulation software Flow-3D.Then the reliability of the model is verified by the Melville classical experimental data,and the validated model is used to study the effect of the change of collar thickness on the local scour depth of bridge piers and the local scour pit morphology of bridge piers.The results show that the scour reduction effect of the collar on the front and rear of the bridge pier is better than that on both sides of the pier.The increase in collar thickness will aggravate the local scour around the bridge pier,especially on both sides of the pier.Under the selected test conditions,the local scour depth around the bridge pier is the smallest,and the scour reduction effect is the best when the collar thickness is 0.05D(D is the diameter of the bridge pier).The scour reduction efficiency can reach 54.4%at this time.The research findings serve as a reference for the local scour protection of bridge piers.

关 键 词：桥梁工程 局部冲刷 冲刷防护 护圈 数值模拟 

分 类 号：TV14[水利工程—水力学及河流动力学]