地震行波效应对大跨连续刚构桥主动控制的影响

INFLUENCE OF SEISMIC TRAVELING WAVE EFFECT ON ACTIVE CONTROL FOR LONG-SPAN CONTINUOUS RIGID-FRAMED BRIDGE

为了探讨地震行波效应对大跨桥梁主动控制地震反应和减震效果的影响规律,推导了地震动多点输入下大跨度桥梁的主动控制计算方法,对一座四跨连续刚构桥梁进行了具有不同视波速的行波输入下的主动控制计算分析,并与地震动一致输入下的计算结果进行比较。结果表明,行波效应对该大跨连续刚构桥梁的主动控制地震反应和减震效果影响显著,对主梁和桥墩均会在较低视波速地震行波输入时表现出不利影响,且对高墩的不利影响大,对低墩的不利影响小。行波效应对纵桥向主动控制的减震效果具有较大不利影响。为此,建议在确定主动控制系统的参数时应考虑地震行波效应的影响以确保控震效果。

In order to study the influence rule of seismic traveling wave effect on seismic response and vibration control effect of active control for a long-span bridge,the calculation approach of active control for long-span bridge is deduced under seismic multiple supported ground motion input.The active control calculation and analysis are performed for a four-span continuous rigid-framed bridge under seismic traveling waves input with different apparent surface velocities,and comparison is made between the calculating results and those under uniform ground motion input.The results indicate that traveling wave effect remarkably influences the active control seismic responses and vibration control effects for the long-span continuous rigid-framed bridge.It is disadvantageous to the beams and the piers under the traveling wave input with lower apparent surface velocity.The bad influence on high piers is great and bad influence on low piers is little.Seismic traveling wave effect is disadvantageous to the longitudinal vibration control effects greatly.Therefore,it is suggested that the traveling wave effect should be considered for the selection of the parameter values of active control system in order to get the designing control effect.