行波输入下大跨斜拉桥减震控制分析

Analysis of Seismic Response Control for Long-span Cable-stayed Bridge under Traveling Wave Input

为了研究行波效应对斜拉桥减震控制效果的影响,以一座大跨斜拉桥为例,建立其有限元模型,计算分析其主动控制、半主动控制和被动控制对飘浮体系斜拉桥的减震效果,并计算了行波输入下斜拉桥的地震反应。半主动控制和被动控制对该斜拉桥的大部分地震反应均能取得良好的控制效果,但是使得桥梁塔底剪力等部分地震反应增大;不同频谱成分的地震动输入显著影响斜拉桥的地震反应和控制方法的减震效果。考虑行波效应后,半主动控制对于该斜拉桥整体地震反应的控制效果优于始终提供最大阻尼力的被动控制;行波效应对斜拉桥主梁具有不利影响,但对桥塔抗震有利,并且对三种控制方法的减震效果没有明显的不利影响。

In order to study the influence of traveling wave effect on control effectiveness of seismic mitigation for cable-stayed bridge, the vibration-suppressed effectiveness of active control, semi-active control and passive control for a long-span floating cable-stayed bridge is calculated and analyzed with its finite element model. The seismic responses of cable-stayed bridge under traveling wave input are calculated. Semi-active control and passive control can get good control efficiency for the most seismic responses of the cable-stayed bridge, but they can make some seismic responses including bottom shearing force of the bridge tower lager. The seismic inputs with different frequency spectrums can evidently influence seismic responses of the cable-bridge and vibration-suppressed effectiveness of the control methods. Semi-active control is better than passive control with most damping force all along for vibration-suppressed effectiveness of the integer seismic responses after considering the traveling wave effect. Traveling wave effect can make bad influence on the beam of cable-bridge, but can be propitious to bridge tower. Bad influence of traveling wave effect on vibration-suppressed effectiveness of the three control methods is not remarkable.