CFRP索大跨斜拉桥的非线性地震响应控制分析

Nonlinear Seismic Response Control Analysis of Long-span Cable-stayed Bridge with CFRP Cables

为探讨碳纤维增强塑料(CFRP)索斜拉桥与普通钢索斜拉桥的地震响应控制优劣性,基于现有试验,以苏通长江公路大桥为参考建立有限元模型,采用等轴向刚度准则换索,并在墩梁、塔梁处设置弹性连接装置和阻尼器作为减震装置;基于弹塑性抗震理论和地震响应分析结果,通过对目标函数作参数敏感性分析,获得不同配索斜拉桥对应于各减震装置的合理设计参数,并比较2种索斜拉桥减震控制的优劣。结果表明:选取相同减震设计参数时,CFRP索斜拉桥可获得较优的减震效果;阻尼器的减震效果比弹性连接装置更优,尤其在内力控制方面。

In order to explore and discuss advantages and disadvantages of seismic response control of the long-span cable-stayed bridge with carbon fiber reinforced plastics（CFRP） cables and conventional cable-stayed bridge with steel cables,taking Sutong Yangtze River Bridge as a reference,the finite element model was established on the basis of existing test.Steel cables were replaced with the CFRP cables by using the axial stiffness equivalent principle in the model.The elastic link device and the damper were set as seismic reduction devices in pier-girder and pylon-girder.Based on the theory of elastic-plastic seismic resistance and the results of seismic response analysis,the parameter sensitivities of object functions were analyzed to obtain rational design parameters of each seismic reduction device.The advantages and disadvantages of seismic reduction control of the cable-stayed bridges with two kinds of cables were compared.The result shows that the bridge with CFRP cables has better seismic reduction effect than the steel cable-stayed bridge with the same seismic reduction design parameters,and the seismic reduction effect of the damper is more effective than that of the elastic link device especially in the aspects of control of internal forces.