设置黏滞阻尼器的纵飘斜拉桥地震响应简化分析方法

针对纵飘体系斜拉桥现有黏滞阻尼器参数设计方法的不足，提出了更为快捷有效的分析方法.首先基于钟摆原理，采用双质点模型简化模拟纵飘斜拉桥的动力响应特征；然后基于能量耗散等效原理，提出了黏滞阻尼器的等效线性模型；最后基于结构动力学原理，建立了设置黏滞阻尼器的纵飘斜拉桥地震响应简化分析方法.在此基础上，针对某主跨392 m的纵飘斜拉桥建立了全桥分析模型，在正弦波作用下，对比分析了全桥模型、双质点简化模型数值解和解析解的计算误差.结果表明:双质点模型数值解计算结果精度较高，可以代替全桥模型的有限元计算结果；解析解与双质点数值解计算结果吻合良好，验证了双质点模型简化分析方法在理论上的可靠性；在不同地震动特性和体系周期下，三者计算误差均满足工程精度要求，表明该简化分析方法具有良好的适用性，可为阻尼器参数优化提供更简便的模型.

A Simplified Analysis Method for Seismic Responses of Floating-System Cable-stayed Bridges With Viscous Dampers

In view of the deficiencies of the existing viscous damper parameter design methods for floating-system cable-stayed bridges, a more efficient and effective analysis method was proposed. Based on the pendulum principle, a double-mass model was used for simplified simulation of the dynamic response characteristics of floating-system cable-stayed bridges. Meanwhile, an equivalent linear model for viscous dampers was proposed according to the principle of energy equivalence. Finally, a simplified analysis method for seismic responses of floating-system cable-stayed bridges with viscous dampers was established based on the principle of structural dynamics. On this basis, a full-bridge numerical model was established for a cable-stayed bridge with a main span of 392 m. Under the action of sine waves, calculation errors of the full-bridge numerical model, the double-mass analytical model and the double-mass numerical model were compared in detail. The results show that, the double-mass numerical solution has high calculation accuracy, and can replace the full-bridge numerical solution; the double-mass analytical solution agrees well with the double-mass numerical solution, which verifies the theoretical reliability of the simplified double-mass analysis method. Calculation errors of the 3 models meet the engineering accuracy requirements under different ground motion characteristics and system periods, indicating that the proposed simplified analysis method has good applicability and provides a more efficient way for damper parameter optimization.