Study on blast-induced vibration of single-hole cylindrical charge

Abstract

It is essential to study the blast-induced vibration of cylindrical charge so as to reduce ground vibration level and protect the surrounding environment. In this paper, the Heelan model is used to study the generation and propagation mechanisms of blasting vibration induced by single-hole cylindrical charge. It shows that the superposition of vibration waves induced by explosives in different positions of the cylindrical charge causes the increase of peak particle velocity (PPV) in the region along the propagation direction of detonation waves. The vector peak particle velocity (VPPV) versus distance for different stemming lengths (SL) indicates that the linear attenuation between the VPPV and the exponential of distance appears only over a certain distance. Hence, the traditional formula for PPV prediction is suitable just in the middle and far field, not in the near field. The influences of charge length, detonation velocity and initiation pattern on the blast vibration are also investigated. The generation of Mach waves is determined by the relationship of scale between velocity of detonation (VoD), P-wave velocity, and S-wave velocity. Over a certain value, the charge length doesn’t affect maximum VPPV, but affects the range of VPPV with relatively large values. Moreover, the bottom and top detonator positions have similar consequences on vibration control in the far field as the influence of limited charge length on blast vibration can be ignored. The VPPV of the middle initiating is almost twice as much as the other two detonator positions in the far field. Thus, in practical blasting, the middle initiating needs to be avoided.