地震作用下全浮漂大跨斜拉桥耗能减震控制研究

以某实际全浮漂大跨斜拉桥为研究应用对象，探讨了全浮漂大跨斜拉桥阻尼器的布置原则，考虑桩-土的相互作用，建立了全桥空间有限元分析模型，针对该非比例阻尼体系，通过基于应变能理论的振型阻尼分别考虑上部结构阻尼、下部结构阻尼和阻尼器阻尼，从而实现结构不同部分不同阻尼引入到有限元分析模型。然后进行了粘滞阻尼器参数优化，得到了最优阻尼系数和最优阻尼速度指数，并进行减震效果分析。研究结果表明：采用粘滞阻尼器可有效控制结构的地震响应，主塔顶位移、主梁位移和主塔底弯矩分别减小为普通全浮漂体系的60.4%、56.7% 、71.8%，各个桥墩支座位移减震效果；随着阻尼系数增加和阻尼速度指数的减小，梁端位移、塔顶位移和阻尼器位移减小，主塔墩底弯矩单调减少，当达到阻尼系数增加和阻尼速度指数的减小到一定值时主塔墩底弯矩控制效果基本稳定。

Energy dissipation control for long span cable-stayed bridge adopting floating system under earthquake

The arrangement principle of damper for long span cable-stayed bridge adopting full-floating system is discussed based on one actual long span cable-stayed bridge, and considering the pile-soil interaction, the spatial finite element model of was build. According to modal damping of strain energy theory, the effect of damping of superstructure, substructure and damper was evaluated, so difference damping of difference component can be induced in FEM of bridge. Then, parameter optimization of fluid viscous damper was processed and the optimal damping velocity index and damping coefficient were obtained, at the same time, effect of energy dissipation for response of bridge under earthquake was analyzed. Researched result show the displacement of main tower, displacement of girder, bending moment at the bottom of main tower of bridge adopting viscous dampers is decreased to 60.4%, 56.7%, 71.8% of ordinary bridge adopting floating system respectively. With the increase of damping coefficient and decrease of damping velocity index, displacement of girder, main tower and damper is decreased and bending moment at bottom of main tower is monotone decrease. The control effect of bending moment at bottom of main tower will be unchangeable when the increase of damping coefficient and decrease of damping velocity index receive a certain value.