Abstract:To investigate decay law of acoustic emission and microseismic activities caused by disturbances associated with multilevel loading and mining blast, a new exponential decay (ED) law was proposed. The results show that the micro-fracture activity decay law after multistage stress loading and blasting disturbance conforms to the ED model, in which the sum of A and n represents the number of initial micro-fracture events, and n represents the level of background micro-fracture events. The ED model can describe the number of initial micro-fracture events with a deviation less than 10%. The ED model outperforms the traditional aftershock models in describing the micro-fracture event decay law in the three cases considered. The ED model can provide a reference for selecting the blasting interval in mines, which is of great significance to maintain the stability of the surrounding rock and ensure safe production in metal mines.

Key words: exponential decay law; blast disturbance; acoustic emission; microseismic activities; metal mine