Study on electric potential response’s spatial distribution characteristics to damaging localization evolution of gas-bearing coal under load

For mining engineering and geological engineering, the deformation and fracture of coal and rock are the essential causes of dynamic disasters. In this paper, the loading experimental system was established on gas-bearing coal, to study the internal relationship between the spatial distribution of EP and the development process of damaging localization on coal mass. The results indicated the temporal response of EP signal could reflect the stress state and damage degree of gas-bearing coal, showing the precursor feather when coal mass failed. Particularly, when the stress dropped suddenly, the EP signal has a sudden mutation, and the acoustic emission (AE) signal suffered the pulsed increase, while the crack grew and expanded rapidly. Furthermore, when local severe damage occurs inside the coal mass, there was abnormal EP spatial distribution with high-value or dense contours in these zones, where simultaneously AE rupture events frequently occurred, and cracks expanded and gathered. The characteristics of EP spatial distribution can reveal the development process of coal mass damaging localization. Meanwhile, the mentioned zones with abnormal EP distribution above are hazard sources inducing coal mass’s instability and failure. The study results provide the foundational research work of fine forecasting on coal and gas outburst disaster hazard.