摘要
为研究吊杆初期轴力和拱肋内倾角对钢管混凝土提篮拱桥的影响,以一座人行桥为研究对象,开展了实桥基本动力特性测试和有限元数值分析。结果表明:通过环境脉动试验测得实桥试验模态,面内反对称一阶模态实测频率为0.859 Hz;面外对称一阶模态实测频率为1.092 Hz;建立空间杆系有限元模型求得桥梁理论模态,面内反对称一阶模态理论频率为0.868 Hz;面外对称一阶模态理论频率为1.071 Hz,从而验证了建立的有限元模型的正确性。以吊杆初期轴力和内倾角为主要参数,进行的拓展参数有限元分析表明:吊杆初期轴力对刚度的影响不大;内倾角从0°到10°逐渐增大,面内频率基本不变,面外低阶频率增加;与平行拱相比,内倾角为10°的钢管混凝土提篮拱桥既增加了面外刚度,又保持了面内刚度,从而说明内倾角的取值是经济合理的。
In order to study the influence of initial axial force on the stiffness of the suspender and inclination angle of arch rib on CFST basket arch bridge,the dynamic characteristics test and finite element numerical analysis of the real bridge were carried out based on a foot bridge.Furthermore,the initial axial force and inclination of the angle were taken as parameters,the extended finite element parameter analysis was carried out.The results indicated that the basic dynamic characteristics of the bridge were as follows:the frequency of the in-plane anti-symmetric first-order mode was 0.859 Hz.The frequency of the out-of-plane symmetric first-order mode was 1.092 Hz.The finite element model was built by the software of NL_Beam3 D,and the theoretical frequency of in-plane anti-symmetric first-order mode was 0.868 Hz.The theoretical frequency of the out-of-plane symmetric mode was 1.071 Hz,which verified the validity of the model.The effect of the initial axial force on the stiffness of the suspender was small.The inclination angle increased gradually from 0 degree to 10 degree,the in-plane frequency was basically unchanged,and the out-of-plane low-order frequency increased.Compared with parallel arch bridge,the in-plane stiffness of concrete-filled steel tubular arch bridge with basket type increased,but the in-plane stiffness is maintained.It was economical and reasonable to take an inclination angle of 10 degrees for concrete-filled steel tubular basket arch bridge.
作者
胡金海
HU Jinhai(Fuzhou Communications Construction Group Co.,Ltd.,Fuzhou 350000,China)
出处
《南昌大学学报（工科版）》
CAS
2019年第2期144-148,156,共6页
Journal of Nanchang University(Engineering & Technology)
关键词
桥梁工程
钢管混凝土
提篮拱桥
动力特性
内倾角
bridge engineering
concrete filled steel tube
arch bridge with basket type
natural vibration prop- erties
inclination angle
