Blast-induced vibration produces very complex signals, and it is very important to work out environmental problems induced by blasting.
Some researchers applied wavelet analysis theory to the signal process of blasting vibration to determine the delay time of short-delay blasting, and suggested variation characteristics of blasting vibration frequency. Some others analyzed the time-frequency distribution characteristics of blasting vibration to determine their main frequency and peak vibration velocity.
Wavelet analysis has been widely used to understand the frequency characteristics of blasting vibration by estimating vibration energy characteristics applied to civil structures, to identify time errors during blasting, and to appreciate vibration characteristics of geological structures and so on.
Pak Thae Un, a section head at the Faculty of Mining Engineering, has made a wavelet analysis of measured blasting vibration signals to identify frequency bands reflecting the changes of blasting vibration parameters such as vibration velocity and energy in different frequency bands. Then, he has discussed frequency characteristics in view of blast source distance and charge weight per delay.
From the analysis results, it can be found that peak velocity and energy of blasting vibration in frequency band of 62.5~125Hz are larger than those in other bands, indicating the similarity to the characteristics in the distribution band (31~130Hz) of main vibration frequency. And most frequency bands are affected by blasting source distance, and the frequency band of 0~62.5Hz reflects the change of charge weight per delay.
If further information is needed, please refer to his paper “Prediction of characteristic blast-induced vibration frequency during underground excavation by using wavelet transform” in “Frontiers of Structural and Civil Engineering” (SCI).
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