大跨山区钢桁梁悬索桥动力特性理论分析和试验研究

选定一座主跨跨径为856 m的简支钢桁梁地锚式特大悬索桥,首先建立桥梁结构空间分析模型,同时考虑非线性因素对结构动力特性的影响,从理论上分析结构的基本动力特性响应。然后通过成桥状态下移动荷载模拟测试,将桥梁结构模态振动响应与相应理论分析结果进行比较分析,并分析结构在跳车和刹车状态下的响应。结果表明:现场各阶基频测试值大于理论计算值,即悬索桥的成桥实际刚度大于其理论值;桥梁结构抗冲击能力较强且具有较强的能量耗散能力。

Research on Dynamic Characteristics and Test of the Large Span Suspension Bridges in Mountain Zones with Steel Truss Girders

An 856m simple-supported steel truss-girder earth-anchored super-large suspension bridge is taken as the engineering project.Firstly,the influence of various nonlinear factors on the structural dynamic characteristics is considered,and an accurate spatial finite element theoretical analysis model of the bridge was established,in order to theoretically analyze its basic dynamic characteristics.Then,the actual bridge structure after the completion of the modal test,jump test and brake test,and compared with the theoretical analysis results.The results show that the measured values of each order fundamental frequency are slightly larger than the theoretical values,that is to say,the actual stiffness of the suspension bridge is slightly larger than the theoretical values.Bridge structure has strong impact resistance and energy dissipation ability.