长周期地震动作用下大跨径斜拉桥响应分析
Analysis on Response of Long Span Cable-stayed Bridge ？？Under Long-period Ground Motion

为研究长周期地震动对大跨径桥梁地震响应的影响，分别选取了若干长周期地震波和普通地震波进行频谱特性对比；以某特大跨径斜拉桥为例，建立了有限元模型，采用非线性时程分析方法对比分析了2类地震动作用下该桥的地震响应。为控制大跨径斜拉桥在2类地震动激励下梁端的位移响应，选用了弹性连接装置和液体粘滞阻尼器2种措施对比研究了其减震效果。结果表明：长周期地震动对大跨径桥梁的位移及内力响应影响显著；在长周期地震动作用下，弹性连接装置的位移控制效率较低，并会导致结构内力的大幅增加；参数合理的液体粘滞阻尼器的控制效果具有较好的广谱性，即在普通地震动和长周期地震动作用下均有较好的减震效果。
In order to study the influence of long？？period ground motion on seismic response of long span bridges, some long？？period ground motions and conventional ground motions were selected, and the comparative analysis on spectral characteristics of these motions were carried out. A long span cable？？stayed bridge was taken as an example to analyze the seismic response of the bridge under two types of ground motions by using nonlinear time？？history method. Elastic connection device and fluid viscous damper were used to mitigate the seismic response of the bridge under two types of the ground motions. In addition, the effects of the two kinds of devices were analyzed. The results show that long period ground motions have great influence on seismic response of the bridge. Elastic connection device has lower efficiency and will introduce more seismic force into the bridge under long？？period ground motion. While, the effect of fluid viscous damper is broad？？spectrum, that is, it has wonderful and stable effect under both long？？period ground motion and conventional ground motion with proper damping parameters