高架交通沿线地面环境振动测试频域分析

In situ measurement and analysis for environmental vibration induced by urban traffic in time domain

为综合研究城市交通所引起的环境振动问题,对基于广州火车站附近高架路诱发进行了沿线地面振动的现场实测;通过对实测数据在频域内进行深入分析,总结出高架路诱发环境振动在频域内的分布特点和传播规律,在最小二乘准则条件下,给出了更加符合环境振动实际传播特征的竖向加速度振级经验衰减公式.结果表明:高架路诱发环境振动和动车组诱发环境振动均呈现脉冲响应特征;高架路诱发环境振动随距桥墩距离增加,脉冲响应特征快速消失;功率谱密度曲线表明随着距离的增加,竖向加速度的频率范围越来越窄,高频成分所占比例越来越小,在15 m处高架路诱发环境振动的高频区域有放大现象,存在局部振动放大区域.与传统振级经验衰减公式相比,文章提出的环境振动振级经验衰减公式更能反映实际环境振动的传播特点.

To study increasingly severe vibration problem induced by urban traffic, field tests of ground vibration were carried out near an elevated bridge at Guangzhou railway station, the propagation laws of environmental vibration were summarized. The mathematical statistics method under the criterion of least-squares was employed to establish the empirical attenuation formula of vertical ground vibration. It is shown that the ground vibration induced by the elevated bridge have the characteristic of impulse. There is a local amplification region when the vibration induced by urban traffic propagates. Compared to the traditional empirical attenuation formula of ground vibration, the empirical attenuation formula proposed by the author can reflect the actual attenuation characteristics of the ground vibration induced by urban traffic.