Multi-resolution wavelet analysis of blasting vibration signals
DU Rong-qiang · Rock and Soil Mechanics · 2009
With the methods of wavelet analysis and fast Fourier transform,actual original signals from engineering project in near,medium and far zones of blasting vibration are separately decomposed and reconstructed;and time signals and spectra of all sub-frequencybands are obtained.On this basis,distribution characteristics of spectra and energy of blasting seismic waves along all zones are studied with Matlab;and it is pointed out,that the values of dominant frequency in blasting vibration zones is in attenuation sequence: near zone,medium zone,far zone;as the scaled distance increases,low frequency bands share higher proportion of total signal energy,while high frequency bands share lower;signals in lower frequency bands have longer duration;in addition to the frequency band that the dominant frequency locates in,when the band is from 0 to 2.441 5 Hz(close to the natural frequency of the buildings),blasting vibration signals in the horizontal direction occupy an assignable proportion of the energy;and thus the aseismic construction in horizontal direction is especially important for building structure designs.