Research on the energy attenuation characteristics of blasting vibration signals based on wavelet packet transformation

Abstract

Blasting vibration monitoring and analysis are the basis and premise of the research on the control of blasting vibration damage.Taking the blasting excavation of small spacing tunnel as the engineering background,Matlab was used to decompose the blasting vibration signals by 5 layers of wavelet packet transformation to obtain the wavelet packet frequency band energy of each node.The frequency band energy distribution characteristics of blasting vibration signal was studied,and the attenuation equation of total energy was proposed by regression analysis of total energy.The research shows that the energy of blasting vibration signal is mainly concentrated in the low frequency band(0~300 Hz).The higher the blasting vibration energy is,the faster the attenuation is.At the same time,energy exhibits that high frequency part attenuates faster and the low frequency part attenuates slower.Energy has a tendency toward low frequency with the increase of distance.The energy attenuation coefficient is twice of the peak velocity attenuation coefficient.When the distance from explosion center is in the range 0 to 30 m,energy attenuates rapidly,and energy attenuation tends to be gentle in the range of 30~53.5 m,while energy is almost zero after more than 53.5 m.The research results have important significance for the further study on the dynamic stability of the existing highway tunnels.

Keywords

• blasting vibration
• wavelet packet transformation
• energy distribution
• energy attenuation