In-Plane Bearing Capacity of CFST Truss Arch Bridges with Geometric Defects  

作　　者：Chao Luo Zhengsong Xiang Yin Zhou Dingsong Qin Tianlei Cheng Qizhi Tang 

机构地区：[1]State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing,400074,China [2]Sichuan Road and Bridge Construction Group Co.,Ltd.,Chengdu,610093,China [3]China Railway First Group Eighth Engineering Co.,Ltd.,Chongqing,401147,China [4]Chongqing Expressway Group Co.,Ltd.,Chongqing,401120,China

出　　处：《Structural Durability & Health Monitoring》2025年第3期683-703,共21页结构耐久性与健康监测(英文)

基　　金：National Natural Science Foundation of China(Grant No.52408314);Science and Technology Project of Sichuan Provincial TransportationDepartment(GrantNo.2023-ZL-03);Science and Technology Project of Guizhou Provincial Transportation Department(Grant No.2024-122-018).

摘　　要：Failure tests were conducted on two concrete-filled steel tubular(CFST)truss arch bridges with a span of approximately 12 m to investigate the influence of initial geometric defects on the in-plane bearing capacity of CFST truss arch bridges.The effects of antisymmetric defect on the ultimate bearing capacity,failure mode,structural response,and steel–concrete confinement effect of CFST truss arch bridges under quarter-point loading were analyzed.On this basis,numerical simulations were conducted to investigate the in-plane bearing capacity of CFST truss arch bridges further under different scenarios.The initial defect formof the archwas obtained by using theoretical deduction,and the theoretical basis for the weakening of the ultimate bearing capacity of the arch bridge caused by geometric defects was clarified.Results indicate that the antisymmetric defect does not change the four-hinge failure mode of the model arch under quarter-point loading but increases the local cracking area and crack density of the concrete inside the pipe.The sine geometric defect with an amplitude of L/250 resulted in a 44.4%decrease in the yield load of the single hinge of the model arch,a 10.5%decrease in the failure load of the four hinges,and a 40.9%increase in themaximum vertical deformation during failure.At the initial stage of loading,the steel pipe and the concrete inside the pipe were subjected to relatively independent forces.After reaching 67%of the ultimate load,the catenary arch ribs began to produce a steel pipe concrete constraint effect.The initial geometric defects resulted in a decrease in the load when the constraint effect occurred.The antisymmetric defects with the same amplitude have a greater impact on the in-plane bearing capacity of the CFST arch bridge than the initial geometric defects with symmetry.The linear deviation at L/4 caused by constructionmust be controlled to be less than L/600 to ensure that the internal bearing capacity of the CFST arch bridge reaches 95%of the design bearing capacity.The str

关 键 词：Geometric defects CFST arch bridge ultimate bearing capacity model test numerical simulation theoretical derivation 

分 类 号：TU3[建筑科学—结构工程]