地震作用下大跨自锚式悬索桥动力响应分析

以雾凇大桥为研究对象,基于通用有限元软件MIDAS/CIVIL,分别通过反应谱法和时程分析法计算了自锚式悬索桥的地震反应规律.分析结果表明：纵向地震作用下主梁梁端位移较大,应采用纵向限位装置或减震装置;横向地震作用与纵向地震作用不存在耦合现象,但是塔底弯矩及剪力动力响应均较大,为控制设计截面;竖向地震作用与纵向地震作用存在耦合现象,主梁及主缆应考虑纵向与竖向地震的共同作用;通过拟合规范反应谱得到的人工波进行时程分析得到的结果整体上大于反应谱计算得到的结果,对构件进行详细抗震设计时应以时程分析为主.

Dynamic Response of Large Span Self-Anchored Suspension Bridge under Earthquake

The seismic response of the Wusong bridge is analyzed though the response spectrum method and the time-history method by adopting the MIDAS/CIVIL. The analysis results show that the longitudi- nal displacement of the main girder is much larger under longitudinal seismic input, so some inhibiting device or dampers should be used to avoid impacting. There is not coupling between longitudinal and lateral seismic excitations, while the seismic response of moment and shear force at the bottom of the main tower is much larger. On the contrary the seismic response of main beam and the main cable should be calculated under the longitudinal and vertical seismic excitations because of the coupling between both of them. Furthermore, the artificial seismic wave fitting standard response spectrum was generated to conduct the time-history analysis and the results are much larger than the results from the response spectrum method. Seismic design of components should be based on the time-history analysis.