Study on Seismic Wave Propagation Characteristic of Deep-hole Loose Blasting in Coal Mine

摘要

According to the distribution of faults in coal face, deep-hole loose blasting scheme is formulated and vibration monitoring is conducted. Obtained seismic wave attenuation rule of deep-hole loose blasting, HHT method is adopted for vibration signal decomposition to research the characteristic of spectrum and the energy distribution of the signal. Research results show that seismic wave propagation characteristic of deep-hole loose blasting accords with hard rock spread rule in Safety Regulation for Blasting, the linear component of the ligature between survey point and explosion source is the largest in the three direction components of vibration velocity, which is resulted from the difference of energy loss between different kinds of seismic wave in propagation process; the duration of blasting vibration is about 150 ms, main energy is concentrated in the low-frequency area of less than 100 Hz, and energy can be divided into several "sub-bands" with frequency distribution. According to attenuation law, the biggest single shot charge of deep-hole loose blasting in the site can be calculated inversely, and measures for reducing blasting seismic hazard in construction are proposed, which would provide a reference for the construction.