Near-field vibration induced by single-hole blasting under different initiation modes

In drilling and blasting, initiation modes determine the propagation direction of detonation wave, which affects the distribution of blast vibration field. In this study, the near-field distribution characteristics of peak particle velocity (PPV) induced by different initiation modes were obtained based on the solution model of the Heelan equivalent elements. The influence law of the initiation mode on the transmission of explosion energy was determined. Through onsite single-hole blasting experiments, the PPV resulting from different initiation modes, such as top initiation, bottom initiation, midpoint initiation, and two-point initiation, were compared and analyzed. The influence of the initiation mode on the transmission of explosion energy was also discussed. The results revealed that the PPV are positively proportional to the blasting load amplitude and the charge length, but inversely proportional to the duration and rising time of the blasting load. The PPV induced by the different initiation modes has the following relationship: bottom initiation > midpoint initiation > two-point initiation > top initiation. The effect of initiation mode on PPV gradually decreased with increasing distance from the blasting centre.