地铁引发环境振动的时频能量评价方法

Time-Frequency Energy Evaluation Method of the Vibration Induced by Underground Subway

摘要: 振动测试与评价是现代城市轨交建设环评工作不可或缺的工作内容之一，如何合理有效的对振动进行评价是近年来的研究热点。基于振动信号时频分析，提出了地铁引发场地振动响应的时频能量评价方法。优选Margenau-Hill-Spectrogram时频分布作为基本时频分布类型，对地铁实测信号的时频特性进行了统计分析，而后对地铁振动信号进行了局部化时频能量和累积时频能量的深入分析，并与传统评价方进行了对比。研究结果表明，地铁引发的场地振动信号具备显著的局部化时频特性，其局部化时频能量和累积时频能量均具有较好的统计稳定性，时频能量评价指标可较好涵盖传统评价指标表征特点的同时，对信号能量的描述更为准确和全面，时频能量评价方法适用于地铁引发场地振动的环境评价。

Abstract: Evaluation of environmental vibration is essential to environmental dynamic testing and analysis. How to reasonably evaluate the vibration is a widely concerned issue. This paper proposed the time-frequency energy analysis method. Firstly, the Margenau-Hill-Spectrogram time-frequency distribution was selected as the optimal analysis distribution and statistical analysis of the time- frequency characteristics of the measured vibration signals was given. Secondly, further analysis of the local time-frequency energy and accumulated time-frequency energy was done. By comparing with traditional evaluation methods, the results show that the vibration induced by underground subway has remarkable local time-frequency characteristics, and that both the local and accumulated time-frequency energy has statistics stability. The time-frequency energy evaluation can be used to replace the traditional evaluation method and to describe the energy accurately and comprehensively. Time-frequency energy evaluation is suitable for the vibration induced by underground subway.