地铁列车运行对路基激振力频率特性研究

Frequency Characteristic of Exciting Force Acting on Metro Subgrade

通过轮轨相互作用关系,建立由上部车辆与下部轨道两子系统组成的地车辆―轨道垂向耦合系统模型,分析了地铁列车运行引起的轨道路基激振力频率特性,讨论了其与建筑结构振动响应的关系以及相关的减振措施.分析结果表明,地铁列车运行对路基产生荷载一般在10 Hz以下,特别集中在5 Hz以内,主要表现为低频段,其频谱范围与一般建筑结构前几阶自振频率接近,容易诱发建筑结构的共振,从而放大结构的振动响应.

The vehicle-rail vertical coupling model, which consists of vehicle and rail systems, is established through the interaction between wheel and rail. The frequency characteristic of the motivation force acting on the subgrade induced by Metro vehicle, its relationship with the self-vibration characteristic of building structure, and the correlative damping measures are discussed. The results show that the motivation force ranges chiefly within 10 Hz, especially within 5 Hz. The frequency range is consistent with the natural vibration-frequency range of conventional building structure which is likely to induce the resonance of building structure and magnify the vibration responses.