A self-anchored suspension bridge balances forces internally without external anchorage requirements, making it suitable for sites where anchorages would be difficult to construct. It often adopts either a full-floating or a semi-floating tower-girder connection system, which may result in large displacement responses along bridge longitudinal direction during earthquakes. This study investigated the efficacy of using the fluid viscous damper (FVD) for seismic control of a single-tower self-anchored suspension bridge. First, the energy dissipation behaviors of the FVD under sinusoidal excitations were studied. It revealed that besides the damper parameters (i.e. damping coefficient and velocity exponent) of an FVD itself, the energy dissipation capacity also relies on the characteristics of external excitations. Therefore, optimum damper parameters added to a structure should be determined on a case-by-case basis. Parametric study was then carried out on the prototype bridge, which indicated a tendency of decreasing the longitudinal deck/tower displacements and tower forces with increasing damping coefficient [Formula: see text] and decreasing velocity exponent [Formula: see text]. Compared with the linear FVD, the nonlinear FVD with a smaller velocity exponent can develop more rectangular force-displacement loops and thus achieve better energy dissipation performance. With selected optimum damper parameters (i.e. [Formula: see text][Formula: see text]kN[Formula: see text]m[Formula: see text][Formula: see text]s[Formula: see text] and [Formula: see text]) for the two FVDs added between the deck and the tower, the longitudinal deck and tower displacements could be reduced by 54%, while the peak bending moment and shear force at the tower base could be reduced by 30% and 19%, respectively. It is concluded that the nonlinear FVD can provide a simple and efficient solution to reduce displacement responses of self-anchored suspension bridges while simultaneously reducing the bending moment and shear force in the tower.

中文翻译：

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使用流体粘性阻尼器的自锚式悬索桥的抗震控制

自锚式悬索桥内部平衡力，无需外部锚固要求，使其适用于锚固难以施工的场地。常采用全浮式或半浮式塔梁连接系统，在地震时可能导致沿桥梁纵向的较大位移响应。本研究调查了使用流体粘性阻尼器 (FVD) 对单塔自锚式悬索桥进行地震控制的效果。首先，研究了正弦激励下 FVD 的能量耗散行为。结果表明，除了FVD本身的阻尼器参数（即阻尼系数和速度指数）外，能量耗散能力还依赖于外部激励的特性。所以，添加到结构中的最佳阻尼器参数应根据具体情况确定。然后对原型桥进行了参数化研究，表明纵向桥面/塔架位移和塔架力随着阻尼系数的增加[公式：见文本]和速度指数的降低[公式：见文本]而减小的趋势。与线性FVD相比，速度指数较小的非线性FVD可以发展出更多的矩形力-位移回路，从而获得更好的能量耗散性能。使用选定的最佳阻尼器参数（即[公式：见文本][公式：见文本]kN[公式：见文本]m[公式：见文本][公式：见文本]s[公式：见文本]和[公式：见文本]）对于添加在甲板和塔之间的两个 FVD，纵向甲板和塔架位移可减少 54%，而塔基处的峰值弯矩和剪力可分别减少 30% 和 19%。得出的结论是，非线性 FVD 可以提供一种简单有效的解决方案，以减少自锚式悬索桥的位移响应，同时降低塔的弯矩和剪力。