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Blast Densification Method: Sound Propagation and Estimation of Psychological and Physical Effects
Journal of Low Frequency Noise Vibration and Active Control, (2003)
Аннотация
Experimental results on the propagation of blasting sounds from underground
explosions for preventing liquefaction of ground are described. Psychological
and physical effects of blasting sounds are estimated by comparison
with previous studies on the effects and evaluation of continuous
low-frequency sounds. The blasting sounds generated by underground
explosions were impulsive low-frequency sounds, which predominantly
involved frequencies of several Hz. Frequencies above 100 Hz tended
to attenuate to a greater degree during propagation from the blasting
area. Sound pressure levels at frequencies above 20 Hz exceeded the
hearing threshold level as well as the threshold for rattling of
building fittings for low-frequency sounds even at a point about
400 m distant from the blasting area. To predict the attenuation
of the blasting sounds and estimate the appropriate distance for
reducing the possibility of complaint, results of numerical calculations
by the parabolic equation method together with meteorological data
are shown.
