城市轨道交通桥梁抗震设计与研究

Seismic Design and Research of Urban Rail Transit Bridge

以城市轨道交通设计实例为主要依据,结合相关规范,根据能量转换原理对轨道交通桥梁抗震设计进行研究。结论为:减小结构体系刚度和加大能量输出是降低结构地震动响应的有效方法。通过控制结构尺寸、设置塑性铰和减隔震支座等方法可以有效降低结构体系刚度;通过设置防震挡块,高阻尼支座等能够加大能量输出。实际震害表明,罕遇地震作用下,抗震计算无法得到结构响应的精确值,结构的内力和变形特征难以把握。根据桥梁破坏机理,通过概念设计才是达到罕遇地震作用下结构抗震性能目标的首选方法。

Based on the urban rail transit design and relevant specifications, this paper studies the rail transit bridge seismic design in the light of the principle of energy conversion. The results conclude that reducing the stiffness of the structural system and increasing the energy output is an effective way to reduce the structural seismic response. Structural system stiffness can be effectively reduced by controlling the size of the structure and mounting plastic hinge and seismic isolation bearing. The energy output can be increased by placing high damping bearing and shock proof block. The actual earthquake damages show that it is hardly possible to get accurate structural response value and difficult to understand the structure internal force and deformation characteristics simply by seismic calculation in case of rare earthquakes. According to the failure mechanism of the bridge, concept design should be prioritized to achieve the structural seismic performances in case of rare earthquake.