多塔斜拉桥纵向约束体系地震反应及减震控制研究

Study on Seismic Response and Damping Control of Longitudinal Constraint System of Multi-tower Cable-stayed Bridge

以某4塔斜拉桥为研究对象,利用ANSYS有限元软件建立全桥模型并对其动力响应进行数值模拟分析。在此基础上,重点考察多塔斜拉桥采用两种塔梁纵向约束体系时应用粘滞阻尼器的减震控制特性,实验结果表明:部分固结体系(中间塔固结)易在被约束塔底产生内力极值,难以消能,减震效果不明显;全自由体系在塔顶和主梁均产生了较大的纵向位移,在抗震设计时需格外关注结构纵向位移。

With regard to a 4-tower cable-stayed bridge as the research object,the whole bridge model was established by ANSYS finite element software and its dynamic response was numerically simulated.On this basis,damping control characteristics of the applied viscous dampers is the main target to research,when two kinds of longitudinal restraint systems of tower girders are adopted for the multi-tower cable-stayed bridge.The experimental results show that:partial consolidation system (intermediate tower consolidation) is easy to produce an extreme value of the internal force at the bottom of the restrained tower.It is so difficult to dissipate energy that the damping effect is not obvious.The full free system produces large longitudinal displacement at the top of the tower and the main beam.In seismic resistance design,special attention should be paid to the longitudinal displacement of the structure.