基于格林函数的浮置板参数对高架桥梁垂向振动的影响

Influence of floating slab parameters on vertical vibration of elevated bridge based on Green function

根据城市轨道交通高架桥梁轻型浮置板线路的结构特点,建立车辆-轻型浮置板轨道-高架桥梁垂向耦合振动模型,利用格林函数得到浮置板轨道与桥梁垂向振动响应的解析表达式,分析在轨道不平顺振动载荷激励下浮置板参数对轨道系统振动的影响。结果表明:浮置板参数的变化对高架桥梁垂向振动的影响主要集中在70 Hz以下的低频段;减小钢弹簧刚度对降低桥梁垂向振动功率、增大振动传播的衰减有利;浮置板厚度对桥梁垂向振动的影响较为复杂,需要根据情况区别对待。

According to the structure characteristics of elevated bridge of urban rail transit with light floating slabs,the vertical coupling dynamics model of the vehicle and light floating slab track and elevated bridge is established.The analytical function of vertical vibration response of the floating slab track and elevated bridge is solved by Green function.The influence of the floating slab parameters on the track system vibration when it is excited by the irregularity vibration loading is analyzed.The results show that the influences of floating slab parameters on the vertical vibration of elevated bridge concentrates on the low frequency(below 70 Hz);the reduction of the steel spring stiffness is beneficial to reduce the vertical vibration power and to increase the attenuation of vibration propagation;the effect of the floating slab thickness on the vertical vibration of elevated bridge is complex,which should be treated differently according to the situation.