桩群布置方式对阻流特性的影响  

Effect of Pile Group Configuration on Flow Resistance

作　　者：臧学平 蒋学炼[1] 庄茜[1] 杨伟超 ZANG Xueping;JIANG Xuelian;ZHUANG Qian;YANG Weichao(Tianjin Key Laboratory of Civil Structure Protection and Reinforcement,TCU,Tianjin 300384,China;BGI Engineering Consultants Ltd,Beijing 100038,China)

机构地区：[1]天津城建大学天津市土木建筑结构防护与加固重点实验室,天津300384 [2]北京市勘察设计研究院有限公司勘察工程分院,北京100038

出　　处：《天津城建大学学报》2021年第2期97-103,共7页Journal of Tianjin Chengjian University

基　　金：天津市教委科研计划重点项目(2019ZD16)。

摘　　要：建设在软土地基上的港口水工建筑物多以桩群作为支撑结构,其阻流特性是工程布置中的重要设计变量.基于RANS方程建立了桩群绕流数值模型,探讨了阻流特性随桩心距和迎流角的变化规律.结果表明,桩群阻力系数和流速折减率呈现同向变化,但两者的极值点对应的迎流角不一致.仅改变纵向桩心距时,桩群阻力系数的极值点出现在迎流角θ=60°,第1~2排桩的阻力分担率随迎流角的增大先减小后增大,第三排桩的波动很小,其余各排桩的变化趋势与第一排桩相反.仅改变横向桩心距时,桩群阻力系数的极值点出现在迎流角θ=30°,各排桩的阻力分担率随迎流角呈明显的波动变化,且波动幅度随桩心距的增大而增大.最后,从受力角度和阻流效果角度分别提出了工程设计中应避免的桩群布置形式.Pile groups are commonly used as the supporting member of port structures built on soft foundation.The flow resistance induced by pile group have substantial influence on the configuration of marine traffic engineering.A RANS model was developed to investigate the variation of flow resistance with the center distance between pile components and the inflow angle.The results show that the drag coefficient on and the velocity reduction behind the pile group show a similar trend with the inflow angle but their inflexions appear at different incident angles of flow.In the case of only changing the center distance between longitudinal pile components,the maximum value of the drag coefficient of pile group appears at the incident angle of 60 degrees.The contribution of the first and second pile rows to the drag coefficient of the pile group first decreases and then increases with the increase of the inflow angle.The contribution of the third pile row to the drag coefficient of the pile group shows a small variation and that of the other pile rows demonstrates opposite trend to the first pile row.In the case of only changing the center distance between transverse pile components,the maximum value of the drag coefficient of pile group appears at the incident angle of 30 degrees.The contribution of each pile row to the drag coefficient of the pile group clearly shows undulation with the inflow angle and the oscillation strengthens with the increase of center distance between pile components.Finally,the configurations of pile group which should be avoided in engineering design are suggested from the aspects of loading and flow resistance,respectively.

关 键 词：桩群 迎流角 桩心距 阻流特性 流速折减 

分 类 号：TU473.1[建筑科学—结构工程]