Propagation waveform characteristics of vibration and sound pressure due to single hole blastings in NATM tunnel

Takamura, Hiroaki*; Hamada, Hajime*; Sato, Toshinori  

In the stage blasting of a mountain tunnel, the condition of single hole initiation in which the effect of other stage does not enter was made by increasing the interval of initiation time between front and rear stages using an electron detonator, and the waveform of vibration and sound pressure at that time was measured. The knowledge obtained from the analysis of sound pressure waveform of single hole blasting is considered to be effective to be utilized for the examination of sound pressure reduction effect of controlled blasting and the analysis of error of noise prediction formula.