Abstract:

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.

Key words: blasting, blasting vibration, wavelet analysis, energy