复式钢管混凝土墩柱轴压性能及承载力提高分析  

AXIAL COMPRESSION PERFORMANCE AND BEARING CAPACITY IMPROVEMENT OF COMPOSITE CONCRETE FILLED STEEL TUBE PIER

作　　者：张玉芬 郝圣旺[1,3] 李栋磊 方永坚 ZHANG Yu-fen;HAO Sheng-wang;LI Dong-lei;FANG Yong-jian(School of Civil Engineering and Mechanics,Yanshan University,Qinhuangdao 066099,China;School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China;Hebei Key Laboratory of Green Construction and Intelligent Maintenance for Civil Engineering,Qinhuangdao 066099,China)

机构地区：[1]燕山大学建筑工程与力学学院,秦皇岛066099 [2]河北工业大学土木与交通学院,天津300401 [3]河北省土木工程绿色建造与智能运维重点实验室,秦皇岛066099

出　　处：《工程力学》2025年第1期209-222,共14页Engineering Mechanics

基　　金：水沙科学与水利水电工程国家重点实验室开放基金项目(sklhse-2020-C01);国家自然科学基金面上项目(52078179)。

摘　　要：为提升矩形钢管混凝土独柱墩的工作性能,在其截面内套异心双圆钢管形成新型复式钢管混凝土墩柱。该文进行了7个墩柱轴压荷载试验,通过对比空钢管柱、矩形墩柱和夹层墩柱分析了新型墩柱的破坏形态、钢管应变发展及承载力和延性差异,最后利用钢管和混凝土的组合效应原理进行组合墩柱轴压承载力提高分析。研究得出新型复式钢管混凝土墩柱轴压破坏形态为鼓曲破坏,其极限承载力较夹层墩柱提高20%,较矩形墩柱提高22%,延性提高效果更为明显;新型墩柱内、外钢管应变发展充分,说明钢管较好地发挥了竖向承载和横向约束混凝土的能力;根据钢板的正则化宽厚比和屈曲后强度计算得出,内、外钢管在混凝土的支撑下承载力提高15%,混凝土在钢管的约束下承载力提高49%;根据约束组合效应得出,新型墩柱整体承载力提高31%;采用等效套箍系数计算的新型墩柱承载力与试验值绝对误差在4%以内,说明新型复式钢管混凝土墩柱符合钢管混凝土统一理论。研究结果表明,新型复式钢管混凝土墩柱在约束混凝土效应方面明显提高,构件的承载力较高、延性较好,具有较强的工程应用前景。In order to improve the mechanical performance of rectangular concrete-filled steel tubular(CFST)pier columns,double exocentric circular tubes are added inside to form a new composite CFST pier column.Seven specimens were tested under axial compression to analyze the new column’s failure mode,strain development,bearing capacity and ductility through comparisons with the hollow steel tubular column,rectangular CFST column and sandwich column.Then the axial bearing capacity improvement of the new composite CFST pier column was analyzed by investigating the confining effect between steel tubes and concrete.The results show that the new pier column under axial compression encounters the local bulging damage;its ultimate bearing capacity is 20% higher than that of the sandwich pier column,and 22% higher than that of the rectangular pier column;meanwhile the ductility increase is more obvious.The strain of inner and outer steel tubes was fully developed,which indicates that the steel tube realizes its vertical bearing capacity and transversely confines the concrete well in the composite CFST pier column.According to the normalized width-to-thickness ratio and post-buckling strength,the inner and outer tubes’bearing capacity is increased by 15% with the concrete’s support,and concrete’s bearing capacity is increased by 49% due to the steel tubes’confining,so the whole pier’s bearing capacity is increased by 31% owing to the confining effect.Compared with the test data,the absolute error of the bearing capacity calculated by the equivalent confinement coefficient is within 4%,indicating that the new composite CFST pier column also conforms to the unified theory of CFST.Therefore,the new composite CFST pier column has a significant improvement in confining concrete,bearing capacity and developing ductility,and thus has a strong engineering application prospect.

关 键 词：新型复式钢管混凝土墩柱 轴压性能 破坏形态 承载力 套箍系数 

分 类 号：TU398.9[建筑科学—结构工程] U443.22[建筑科学—桥梁与隧道工程]