Analysis And Research Of The High-speed Train Seismic Signal

Inversion of subsurface structures using seismic observation records is an important geophysical method to detect crustal structures.With the increasing demand for underground structure detection in urban areas,the demand for green environmental protection source is also increasing,so a variety of conventional artificial sources,including explosives source,will gradually be no longer applicable.Therefore,using train vibration as seismic source to detect underground structure has become a new significant exploration in the field of underground structure research.High-speed trains produce strong vibration signals,which are different in different operating environments.These vibration signals not only contain structural information of trains,but also structural information of tracks and foundations.In this paper,the short time Fourier transform,the wavelet transform,the synchronous compression STFT trasform and the synchronous compression wavelet trasform are firstly applied to the synthesized signal and the measured high-speed train seismic signal,through the time-frequency comparison analysis,the superiority of the synchronous compression wavelet trasform is found,that is,it has higher time-frequency resolution.Then the time-frequency analysis of the measured high-speed train seismic signals in baoding area is carried out by means of the synchronous compression wavelet trasform,and the signal characteristics of the measured high-speed train seismic signals in different operating states are obtained.The generation mechanism of the equal-interval characteristic lines of the measured high-speed train seismic signals in the state of uniform motion is discussedIn this paper,the characteristics of the high-speed train seismic signals under different operating environments in shenzhen are analyzed by using the synchronous compression wavelet trasform,and the characteristic differences of the high-speed train seismic signals under different operating environments are obtained,which indicates that the high-speed train seismic signals contain information of underground structure and geological environment.In this paper,the wavelet threshold denoising and the synchronous compression wavelet trasform threshold denoising are firstly applied to the synthesized signal.Through comparative analysis,the superiority of synchronous compression wavelet trasform threshold denoising is shown,Then uses the synchronous compression wavelet trasform threshold denoising technology to separate the background noise signals and the actual high-speed train seismic signals.The results show that this threshold denoising technique can accurately separate the background noise signals and the actual high-speed train seismic signals from the measured high-speed train seismic signals.