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

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 compar- ing with traditional evaluation methods, the results show that the vibration induced by under- ground 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.