大跨度斜拉桥非线性粘滞阻尼器参数研究

为研究地震作用下非线性粘滞阻尼器参数的不同选取对漂浮式大跨度斜拉桥纵向限位性能的影响。通过非线性动力时程分析法对某大跨度斜拉桥中非线性粘滞阻尼器的阻尼系数C和阻尼指数ξ进行参数敏感性分析,与该桥在未设置粘滞阻尼器状态下的地震响应进行比较分析和安全评价。提出选取阻尼系数C和阻尼指数ξ的控制方法和公式。结果表明:斜拉桥纵桥向设置粘滞阻尼器后,通过调节粘滞阻尼器的参数能有效降低结构在地震作用下关键部位的相对位移;非线性粘滞阻尼器在限制主梁纵向位移时对跨中竖向位移有放大作用;合理的阻尼参数对提高地震作用下斜拉桥安全性有重要影响。

Parametric Study on Nonlinear Viscous Damper of Long-Span Cable stayed Bridge

To investigate the influences on longitudinal limit performance of floating-type long-span cable stayed bridge because of the different nonlinear viscous damper parameters under the action of seismic force,by using nonlinear dynamic time-history analysis method,the article carried out the sensitivity analysis for the different damping coefficient C and damping exponent ξ of nonlinear viscous damper which was used in a long-span cable stayed bridge.Afterwards,the results of sensitivity analysis were compared with the seismic response without viscous damper in this bridge,and the safety evaluations for both situations were also carried out.Furthermore,the control methods and formulas of selecting the damping coefficient C and damping exponent ξ were provided in this article.The results of parametric sensitivity analysis indicate that after setting the nonlinear viscous damper in longitudinal direction of cable stayed bridge,the relative displacements at key positions of the bridge can be reduced effectively by adjusting the parameters of the viscous damper;but important amplification effect on the vertical displacement at the midspan of the bridge occurs when limiting the longitudinal displacement of main girder by nonlinear viscous damper.So,it is significant to reasonably select the damping parameters for the purpose of improving the safety performance of cable stayed bridge under the action of seismic force.