考虑吊杆断裂动力作用的钢管混凝土拱桥等效静力计算方法  

Equivalent static calculation method for concrete filled steel tubular arch bridges considering dynamic effect of hanger fracture

作　　者：陈康明[1,2] 吴庆雄[1,3] 罗健平 王欢围 Chen Kangming;Wu Qingxiong;Luo Jianping;Wang Huanwei(College of Civil Engineering,Fuzhou University,Fuzhou 350116,China;Key Laboratory of Fujian Universities for Engineering Structures,Fuzhou University,Fuzhou 350116,China;Fujian Provincial Key Laboratory on Multi-Disasters Prevention and Mitigation in Civil Engineering,Fuzhou University,Fuzhou 350116,China)

机构地区：[1]福州大学土木工程学院,福建福州350116 [2]福州大学福建省高校工程结构重点实验室,福建福州350116 [3]福州大学福建省土木工程多灾害防治重点实验室,福建福州350116

出　　处：《土木工程学报》2023年第6期63-74,共12页China Civil Engineering Journal

基　　金：国家重点研发计划(2017YFE0130300);国家自然科学基金(52078137,51678154);福建省自然科学基金杰青项目(2019J06009)。

摘　　要：为简化吊杆断裂后拱桥剩余结构动力响应计算过程,提升中、下承式钢管混凝土(CFST)拱桥断索时的强健性,采用动力系数考虑断索过程的动力效应,建立一种考虑断索动力作用的中、下承式CFST拱桥等效静力方法;设计并制作跨径20m的下承式CFST拱桥大比例缩尺试验模型,研发一种电磁铁断索触发装置实现了吊杆瞬间断裂模拟,开展吊杆断裂后拱桥剩余结构的动力响应试验研究;采用ANSYS/LS-DYNA软件建立可考虑吊杆断裂过程的有限元模型,并进行试验与有限元结果的对比分析。构建11种不同跨径的中、下承式CFST标准拱桥,通过不同动力系数下标准拱桥断索时静力效应与动力效应的对比分析,确定各标准拱桥在不同吊杆断裂时的动力系数取值。研究结果表明:研发的电磁铁断索触发器可实现0.1s内断索,准确模拟实际吊杆断裂过程;吊杆断裂对纵梁位移与应力的影响远大于对拱肋的影响,长吊杆断裂对纵梁和拱肋的位移与应力的影响大,次短吊杆断裂对相邻吊杆索力的影响大。采用等效静力计算方法进行中承式CFST拱桥受力分析时,纵梁和吊杆的动力系数均可取1.8,进行下承式CFST拱桥受力分析时,纵梁和吊杆的动力系数可分别取1.8和1.7。In order to simplify the calculation process for the dynamic response of residual structure after hanger failures,and to improve the robustness of the through and half-through concrete-filled steel tube(CFST)arch bridge when the hanger is fractured.The dynamic effect of hanger fracture process is considered by using dynamic coefficient,and an equivalent static calculation method for through and half-through CFST arch bridge considering the dynamic effect of hanger fracture is presented.A large-scale test model of 20 m span CFST arch bridge is conducted,an electromagnet trigger device of hanger fracturing is developed to simulate the hanger fracturing instantly in the real bridge,the dynamic response test of the remaining structure of the arch bridge after the hanger fracture is carried out.A finite element(FE)model in consideration of the hanger fracture dynamic process has been established by using ANSYS/LS-DYNA,and in addition the results of test and FE analysis are compared.Eleven kinds of CFST standard arch bridges with different spans are constructed,and by comparing the static and dynamic effects of standard arch bridge with different dynamic coefficients,the dynamic coefficients of standard arch bridge with different hanger fracture are determined.The research results show that the proposed electromagnet trigger device of hanger fracturing can realize the hanger fracturing within O.1 s,which accurately simulates the fracture process of an actual bridge hanger.The influence of hanger fracturing on the displacement and stress of girder is much greater than those of the arch rib.In particular,the fracturing of long hanger has the greatest influence on the displacement and stress of girder and arch rib.The fracture of the secondary short hanger has relatively great influence on the cable force.When the equivalent static calculation method is used to analyze the force of the middle through CFST arch bridge,the dynamic coefficients of both the girder and hanger can be taken as 1.8,while when analyzing the mechan

关 键 词：中、下承式钢管混凝土拱桥 吊杆断裂 断索试验 动力响应 等效静力法 动力系数 

分 类 号：TU392.3[建筑科学—结构工程]