大跨度高墩连续刚构桥黏滞流体阻尼器参数敏感性分析

Parameter Sensitivity Analysis of Viscous Fluid Damper for Long-span Continuous Rigid Frame Bridge with High Pier

为研究桥梁两侧交界墩上布置黏滞流体阻尼器对桥梁地震响应的影响,以某处于高烈度震区的典型大跨度高墩连续刚构桥为研究对象,利用数值模拟方式分析了黏滞流体阻尼器的力学参数与桥梁地震响应之间的数学关系,探讨了大跨度高墩连续刚构桥中黏滞流体阻尼器力学参数的合理取值。结果表明,黏滞流体阻尼器的使用会显著减小该大跨度高墩连续刚构桥的受力与变形,进而显著提高了该连续刚构桥的抗震性能;该连续刚构桥各肢墩墩顶位移、墩顶与墩底弯矩与阻尼系数呈反比关系,与速度指数成正比关系;综合考虑黏滞流体阻尼器的减震效果与经济效益,建议采用阻尼系数为1 200 kN/(m/s)^(ξ)、速度指数为0.2的黏滞流体阻尼器,选用该参数的阻尼器后,各肢墩的位移与受力减震率在30%~50%之间。

To study the influence of viscous fluid damper on the seismic response of bridge,a typical long-span continuous rigid frame bridge with high piers in high intensity earthquake area is taken as the research object,and the mathematical relationship between the mechanical parameters of viscous fluid damper and the seismic response of bridge is analyzed by numerical simulation.The reasonable value of the mechanical parameters of the viscous fluid damper in the long-span and high-pier continuous rigid frame bridge is discussed.The results show that,the application of viscous fluid damper can significantly reduce the stress and deformation of the long-span and high-pier continuous rigid frame bridge,and then significantly improve the seismic performance of the continuous rigid frame bridge.The displacement of pier top,bending moment of pier top and bottom are inversely proportional to damping coefficient and proportional to velocity index.Considering the damping effect and economic benefit of the viscous fluid damper,the viscous fluid damper with damping coefficient of 1200 kN/(m/s)^(ξ)and velocity index of 0.2 is recommended.After using the damper with the parameters,the seismic-reduction rates of the displacement and stress of each pier are between 30%and 50%.