以某三塔悬索桥为背景,采用有限元计算分析,研究了中塔塔梁间设置弹性索对三塔悬索桥地震响应的影响,以及设置柔性中央扣对桥梁地震响应的影响,提出可采用弹塑性减震装置作为悬索桥中央扣,并分析了弹塑性中央扣对桥梁地震响应的影响,探讨了不同减震体系下三塔悬索桥减震效果。结果表明,中塔塔梁间设置弹性索对中塔地震受力不利；柔性中央扣是地震作用下悬索桥易损构件,可采用弹塑性减震装置作为悬索桥中央扣；弹塑性中央扣能有效控制三塔悬索桥纵向地震位移,并改善中塔地震内力；采用弹性索和弹塑性中央扣组合减震体系后,悬索桥位移减小更明显,且中央扣减弱弹性索对中塔内力的不利影响,弹塑性中央扣应用于三塔悬索桥中能有效提升桥梁抗震性能。

Based on a triple-tower suspension bridge, using the finite element analysis method, the influence of elastic cable on the seismic response of the suspension bridge was studied, the seismic response of the bridge with the flexible central buckle was analyzed, the elastic-plastic seismic mitigation device was taken as the central buckle, and the influence of the elastic-plastic central buckle on the bridge seismic response was investigated, the seismic mitigation effectiveness of the bridge with different seismic mitigation systems was discussed. The results show that the elastic cable between the tower and deck is unfavorable to the seismic forces of the middle tower, the flexible central buckle is vulnerable to the suspension bridge under earthquake loads. The elastic-plastic device can be used as the suspension bridge central buckle. By installing the elastic-plastic central buckle, the longitudinal seismic displacement of deck can be effectively controlled and the seismic forces of the tower can be improved. When the combination of elastic cable and elastic-plastic central buckle was installing, the displacement of the suspension bridge is reduced more obviously, the adverse effect of the elastic cable on the middle tower can be mitigated. The seismic performance of the triple-tower suspension bridge can be effectively improved by the application of elastic-plastic central buckle.

U442.25

国家自然科学基金项目