Characteristics of blasting vibration induced by short-delay cylindrical charges based on Heelan model

As the electronic detonators can control the detonation error within 1 ms, short-delay blasting was nowadays proposed to replace multi-hole simultaneous blasting to reduce the vibration hazards. In this study, the Heelan model was used to study blast-induced vibration of short-delay cylindrical charges. The influence of delay time on the vector peak particle velocity (VPPV) of superimposed vibration waveforms was analyzed and the calculating formula of the shortest delay time between adjacent holes based on vibration reduction was established. It is found that as the delay time increases, the overlapping area of VPPV becomes further away from the explosion source. The main influencing factors for the shortest delay time between holes include the distance between the monitoring point and the explosion source, the difference between P wave and S wave velocities, and the duration of S wave in the first and second explosion holes. As the distance from the explosion source increases, the shortest inter hole delay time based on vibration reduction also increases. The research results have guiding significance for the control of blasting vibration in underground mines.