Analysis of surface transient charge and the interdependent response of microseismic signal during the deformation of coal

Abstract

The stress changes, transient charges and microseismic signals of briquette samples during uniaxial compression failure were monitored and analyzed by using the self-made experimental system for measuring transient charges and microseismic signals on the surface of briquette.The experimental results show that the surface of briquette sample will produce transient charge during uniaxial compression failure, and the charge signal changes instantaneously and monopulse, and lasts for a long time, about 5~12 s.However, the microseismic signals show obvious paroxysmal occurrence with a short duration of about 0.2~0.4 s.Surface transient charges and microseismic signals are strongly correlated with stress changes, and their overall trend of change has a high synchronization in time scale.The time difference between the peak values of the two signals is about 0.08~0.5 s.There is a critical point of energy release in the process of sample failure, which corresponds to the time of sudden stress change.By using the time scale consistency of surface transient charge and microseismic signal and the characteristics of the critical point of energy release, the process of coal and rock mass failure can be predicted and analyzed more accurately.

Keywords

• briquette sample
• surface transient charge
• microseismic signal
• synchronization