Time-frequency characteristic analysis of blasting vibration based on wavelet transform

The time-frequency process of blasting vibration is a nonstationary random one with short duration, and analysis is made on the process by means of wavelet transform technique. According to the multiresolution decomposition of discrete wavelet transform, the time history signal of blasting vibration may be expressed by different level reconstructed signals of wavelet decomposition. By using these signals, the relative energy distributions of blasting vibration in different frequency bands and the regularity of vibration strength varying with time can be obtained. Blasting vibration measurement shows that the time-frequency characteristic analysis based on wavelet transform yields more accurate information details of blasting vibration, compared with the frequency spectra analysis on the conventional Fourier transform. The suggested method provides a new approach for analyzing the structural safety under blasting vibration conditions.