Energy dissipation of coal and rock during damage and failure process based on EMR

The physical and mechanical change processes of coal and rock are closely related to energy transformation, and the destruction and failure of coal and rock is an instability phenomena driven by energy change. However, the energy change of large-scale coal rock in the mine site is hardly calculated accurately, making it difficult to monitor coal-rock systematic failure and collapse from the perspective of energy. By the energy dissipation EMR monitoring system, we studied the damage and failure of coal and rock with bursting liability from the energy dissipation point using the geophysical method-EMR, and explored the energy dissipation characteristics during uniaxial compression and their main influencing factors. The results show that under displacement-control loading mode, there are 2 types of energy dissipation trends for both coal and rock with bursting liability. The type I trend is a steady increase one during the whole process, therein, the energy dissipation of rock samples is accelerated at the peak load. The type II trend energy is a W-shaped fluctuating one containing 6 stages. Under load-control loading mode, there is one energy dissipation trend of shock downward-steady rise. Besides that, rock samples also present a trend of 4 stages. The energy dissipation characteristics of coal and rock during loading failure process can be used as effective criteria to assess whether they are in a stable or destructive stage. The factors influencing energy dissipation in the loading failure process of coal and rock mainly include strength, homogeneity, and energy input efficiency. (C) 2015 Published by Elsevier B.V. on behalf of China University of Mining & Technology.