【摘要】 以六塔斜拉桥型的嘉绍大桥为工程背景,研究了多塔斜拉桥采用纵向部分约束体系的地震反应特点,在此基础上详细考察了多塔斜拉桥纵向部分约束体系采用黏滞阻尼器的减震控制特性及其减振优化控制方法。研究结果表明:(1)多塔斜拉桥采用部分塔梁纵向固结的约束体系,其减震控制目标是减小塔梁部分固结造成的"内力集中效应";(2)多塔斜拉桥设置黏滞阻尼器可以显著减小塔梁固结处的塔底内力反应和桥塔与主梁间的纵向相对位移反应,但会明显增大塔梁自由处的塔底内力反应,并略微增大主梁与桥墩间的纵向相对位移反应;(3)黏滞阻尼器的阻尼系数与多塔斜拉桥塔底总内力的关系曲线为一单峰凹凸曲线,阻尼系数与塔底内力不均匀分布系数和阻尼器最大输出力的关系曲线为一单调变化曲线。根据这一变化特性,分别选取塔底总内力和塔底内力不均匀分布系数作为目标函数建立了多塔斜拉桥纵向部分约束体系的减震优化控制方法。更多还原

【Abstract】 With regard to a six-tower cable-stayed bridge-Jiashao Bridge,the characteristics of seismic responses of multi-tower cable-stayed bridges using partially constrained system under earthquake actions were analyzed,on the basis of which the vibration control effect and optimal control method on multi-tower cable-stayed bridges using partially constrained system were analyzed with the viscous damper. The analysis results reveal that:( 1) The objective of seismic control on multi-tower cable-stayed bridges using partially constrained system is to reduce the effect of internal force concentration due to the partially constraint between the bridge tower and girder;( 2) The installation of viscous damper can significantly reduce the internal force at the bottom of the bridge tower restrained with the girder and the longitudinal relative displacement between the girder and towers. However,the internal force at the bottom of the bridge tower unrestrained with the girder can be significantly increased and the longitudinal relative displacement between the girder and piers can be increased a little;( 3) The relationship between the damping coefficient of viscous dampers and total force at the bottom of all bridge towers is single concave convex curve. And the relationship between the damping coefficient and non-uniform distribution coefficient of bridge towers is monotone curve together with the maximum damping force of viscous dampers. According to these curves,the optimalseismic control method for multi-tower cable-stayed bridges using partially constrained system is presented using the objective functions of total force at the bottom of all bridge towers and non-uniform distribution coefficient of bridge towers,respectively.更多还原