行波效应对大跨斜拉桥减震控制的影响

为了研究行波效应对斜拉桥减震控制地震反应的影响, 推导了多点地震动输入下的大跨桥梁减震控制计算方法, 以一座大跨飘浮体系斜拉桥为实例, 在桥塔和桥墩处设置阻尼器, 建立其三维有限元模型, 分析了行波输入下半主动控制和被动控制对斜拉桥的减震效果。计算结果表明: 半主动控制比较缓和地控制桥梁的地震反应, 而被动控制则急剧地控制桥梁的地震反应, 因此, 要慎用被动控制; 行波效应对无控制、半主动控制和被动控制斜拉桥的桥塔均具有很小的不利影响, 仅使桥塔内力增大约10%, 对主梁均具有显著不利影响, 使主梁内力增大近8倍; 行波效应对半主动控制和被动控制减震效果的不利影响很小, 没有出现明显的控制效果变差的现象。

Influence of traveling wave effect on seismic mitigation control for long-span cable-stayed bridge

In order to study the influence of traveling wave effect on the seismic response of vibration mitigation control for cable-stayed bridge,a calculation method of seismic mitigation control for long-span bridge was presented under multiple ground motion inputs,and the vibration-suppressed effectivenesses of semi-active control and passive control for a long-span floating cable-stayed bridge with dampers set on towers and piers were calculated and analyzed by its 3D finite element model. Calculation result indicates that semi-active control method can gently control the seismic response of bridge,passive control method can sharply control the response,so passive control method should be used carefully. Traveling wave effect makes little bad influence on the tower of cable-stayed bridge for uncontrol,semi-active control and passive control with the maximal augment of 10% for internal force,but it can make serious bad influence on the beam with maximal augment of about 8 times for internal force. The bad influences of traveling wave effect on the vibration-suppressed effectivenesses of semi-active control and passive control are little with no obvious bad control effectivenesses. 14 figs,10 refs.