自锚式悬索桥动力特性及地震反应特点

Dynamic Analysis of a Self-Anchored Suspension Bridge

结合一座自锚式悬索桥的工程设计实例,研究了该桥的动力特性及地震反应的特点。采用反应谱和时程法对该桥进行了线性地震反应分析,初步探讨了自锚式悬索桥地震反应的特点。分析了冲刷深度、高阶振型和竖向地震动对该桥抗震性能的影响。结果表明:局部冲刷情况减小了塔底的弯矩响应;高阶振型对自锚式悬索桥的地震反应有一定的影响,特别是对主塔的剪力响应;而竖向地震动对主梁弯矩和主塔的动轴力贡献很大。

Based on an engineering design case of a Self-anchored suspension bridge, the linear seismic response analysis was performed by employing response spectrum and time history analysis method, respectively. The characteristic of seismic response of the bridge was discussed, and the effect of scour depth, higher modes and vertical earthquake on the bridge was researched. The results indicate that local scour condition decrease the moment response in the bottom of pylons, the higher modes have some contribution to seismic responses of the bridge, especially to the shear force response of pylons, vertical earthquakes have significant influence on moment of girder and axis force of pylons