Reduction of blast-induced vibration in the direction of tunneling using an air-deck at the bottom of a blasthole

The present study proposed an air-deck method for reducing blast-induced vibration in the direction of tunneling. The air-deck method involves the use of a thin paper-tube at the bottom of a blasthole. The vibration-reduction effect and excavation efficiency of the air-deck method were quantitatively investigated through numerical and experimental studies. The parameter considered in the numerical and experimental studies was the length of the air-deck at the bottom of a blasthole. The numerical and experimental results agreed well with each other. It was revealed that the air-deck at the bottom of a blasthole reduced blast-induced vibration in the direction of tunneling. The air-deck method was also found to be more effective than the conventional method of reducing the advance per round. Finally, design conditions for reducing blast-induced vibration in the direction of tunneling were proposed by introducing the concept of factor of safety.