Energy Distribution Law of Dynamic Failure of Coal-Rock Combined Body

The rock burst must be generated by energy. In order to explore the distribution law of energy in coal-rock system, based on the structural characteristics of coal and rock and the mechanical characteristics analysis of coal-rock combined body model, the calculation formula of energy distribution was given before the damage of same diameter coal-rock combine body and nonsame-diameter coal-rock combined body; the uniaxial compression experiments were carried out on the combined body, and the energy distribution before the failure of the combined body was calculated by using the energy distribution calculation formula. The results show that the greater the difference in hardness between the components of the combined body, the stronger the outburst proneness; the energy mainly accumulates on the weak component before the combined body is destroyed, and the hard components act as a clamping device. When the soft layers and the hard rock layers are interbedded, the energy accumulation ability of the soft rock layer is stronger than that of the hard rock layer, and the weak rock layer is the main carrier of energy accumulation. According to this, from the perspective of energy accumulation layer, for the energy-bearing structure, direct release energy and indirect release energy two kinds of rock burst prevention and control concepts and corresponding antiburst measures were proposed. At the same time, engineering practice, microseismic monitoring, and on-site measurement were conducted in Junde Coal Mine. The results show that the blasting pressure relief for the weak coal seam and the hard roof destroys the energy-bearing structure formed by the fine sandstone-coal-fine sandstone and effectively releases the energy and has a remarkable antiscour effect.

Automated summary

This study explored the distribution law of energy in coal-rock system by analyzing the mechanical characteristics of coal-rock combined body, demonstrating that components of greater hardness difference are more prone to rock burst. Before destruction, energy mainly accumulates on the weaker component while the harder components act as clamping devices.