大型薄壁钢管桩支架屈曲失稳研究  

Research on the Buckling Instability of Large Thin-walled Steel Pipe Pile Brackets

作　　者：张萌 彭泽豹 陈宇航 屈捷 王建[1] ZHANG Meng;PENG Ze-bao;CHEN Yu-hang;QU Jie;WANG Jian(College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,Jiangsu Province,China;Zhejiang Ninghai Pumped Storage Co.,Ltd,Ninghai 315600,Zhejiang Province,China)

机构地区：[1]河海大学水利水电学院,江苏南京210098 [2]浙江宁海抽水蓄能有限公司,浙江宁海315600

出　　处：《中国农村水利水电》2023年第12期234-240,247,共8页China Rural Water and Hydropower

基　　金：国家自然科学基金项目(51779084)。

摘　　要：薄壁钢管桩支架是大跨度渡槽等工程施工中常用的临时支撑结构,因其长细比较大,压杆稳定问题较为突出,因此准确计算其结构安全系数是设计中的关键。为研究应力集中对薄壁钢管桩支架屈曲失稳的影响,结合某大型渡槽工程,同时采用梁单元和壳单元建立钢管桩支架模型,利用有限元软件ABAQUS对比分析了不同径厚比和支架高度下钢管桩支架的屈曲临界荷载。结果表明,两种模型下钢管桩支架的屈曲失稳模态存在明显差异,梁单元因无法较好地反应局部应力特征,得到的结构安全系数偏大,计算结果偏危险。对于薄壁钢管桩支架,两种模型下屈曲临界荷载的相对差值与径厚比和初始缺陷成正相关。当钢管径厚比大于20时,两者之间的相对差值大于11.4%,实际工程中建议采用壳单元进行稳定验算。The thin-walled steel pipe pile bracket is a temporary support structure commonly used in the construction of large-span aque⁃ducts and other projects.Because its slenderness ratio is relatively large,the buckling instability problem is more prominent.Therefore,the accurate calculation of its structural safety factor is the key in the design.In order to study the effect of stress concentration on buckling insta⁃bility of steel pipe pile bracket,combined with a large-scale aqueduct project,the beam elements and shell elements are used to establish steel pipe pile bracket models,and the buckling critical load of steel pipe pile bracket under different diameter-thickness ratios and bracket heights are compared and analyzed through the finite element software ABAQUS.The results show that there are obvious differences in the buckling instability modes of steel pipe pile bracket under different models.Because the beam element cannot reflect the local stress charac⁃teristics well,the obtained structural safety factor is relatively important,and the calculation result is dangerous.For the thin-walled steel pipe pile bracket,the relative difference of buckling critical loads under the two models is positively correlated with diameter-thickness ratio and initial imperfection.When diameter-thickness ratio is greater than 20,the relative difference between the two is greater than 11.4%.In actual engineering,we recommend using shell element for stability checking.

关 键 词：钢管桩支架 屈曲失稳 单元类型 径厚比 初始缺陷 

分 类 号：TV34[水利工程—水工结构工程]