高架轨道桥梁新型橡胶减振支座的减振效果分析

为减小列车在高架轨道桥梁上运行引起的环境振动,开发了一种新型橡胶减振支座。此新型支座采用高阻尼厚层橡胶块倾斜布置的设计方案,在实现竖向减振的同时还可以提供较大的横向水平刚度;为研究这种新型支座的减振效果,建立了上部质量块-橡胶减振支座-桥墩体系有限元模型,采用竖向扫频激振的方式对其减振效果进行数值模拟;设计了一系列工况对影响新型支座减振效果的因素进行分析。研究表明:激振力幅值对新型支座的振动插入损失无影响,但增大桥墩高度会导致新型支座的振动插入损失减小;当激振力幅值取140 kN、桥墩高度取6 m时,新型支座的振动插入损失为17.53 dB;在满足承载力的情况下,增大橡胶块的倾角、增大橡胶块中橡胶层总厚度、减少橡胶层数的划分,可以降低新型支座的压缩刚度,进而提高新型支座的减振效果。

Vibration reduction effect of a novel rubber anti-vibration bearing for rail transit viaduct

A novel rubber anti-vibration bearing was developed to reduce the environmental vibration caused by train running on the rail transit viaduct.This novel bearing adapts a design of arranging high damping thick rubber block with slope, which can reduce vertical vibration and provide a large horizontal stiffness.The finite element model of the upper mass block-rubber bearing-pier system was established to study the vibration reduction effect of the novel bearing through vertical sweep excitation.Then, a series of working conditions were designed to analyze the factors which can influence the vibration reduction effect of the novel bearing.Results indicate that the amplitude of excitation force has no effect on the vibration insertion loss of the novel bearing, but the vibration insertion loss will be reduced if the pier height increases; when the excitation force is 140 kN and the pier height is 6 m, the vibration insertion loss of the novel bearing is 17.53 dB; when the bearing capacity is met, increasing the inclination angle of rubber blocks and the total thickness of rubber layer, and reducing the number of rubber layer, can reduce the compression stiffness of the novel bearing and then improve the vibration reduction effect.