Objective The multistage sedimentary and tectonic evolution of coal seams in China has led to the formation of environments with the coexistence of multiple disasters including gas outbursts, water inrushes, and rock bursts. To address the chain evolution of these disasters induced by the coupling of high in situ stress, high water pressure, and intense mining under the condition of deep coal mining, this study systematically investigated the coupling mechanisms and collaborative prevention and control techniques of multiple dynamic disasters in coal seam roofs.
Methods Based on the regional tectonic characteristics and the delineation of coal-bearing tectonic units, this study systematically revealed the coupling mechanisms of multiple dynamic disasters in coal seam roofs by integrating geomechanical analysis, disaster evolution analysis, and technical mode construction. Accordingly, this study innovatively developed the technology system for collaborative prevention and control of multiple disasters.
Results and Conclusions The results indicate that with an increase in the coal mining depth, disasters in coal seam roofs have evolved from a single mode to a composite mode consisting of gas outbursts, rock bursts, and water disasters. In deep environments characterized by high in situ stress, high formation temperature, high water pressure, and strong mining disturbance, the chain effects of stress redistribution, fracture propagation, and energy accumulation induce the coupling effects of disasters such as rock burst initiation and water-gas interactions. By transcending the traditional binary coupling framework of rock bursts and gas outbursts, this study systematically developed a coupling model of multiple disasters including significantly thick aquifer-induced rock bursts and the linkage between water in the detachment layer and thick, hard coal seam roofs. Using this model, this study clarified the cross-disaster coupling mechanisms due to the gas and liquid migration and energy release induced by the interconnection of mining-induced fracture networks. This study innovatively proposed a technique path integrating source-based identification, classification-based control, and collaborative prevention and control. Furthermore, it developed five prevention and control modes characterized by surface-underground linkage and regional-local collaboration, involving critical technologies like multistage fracturing using directional long boreholes and the modification of L-shaped surface well groups. The results of this study will provide a theoretical basis and technical path for addressing the challenge of the collaborative prevention and control of multiple disasters in deep coal mining.
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