Meitan xuebao (Mar 2024)
Mine microseismic and electrical coupling monitoring technology
Abstract
With the increase of the depth, mining intensity and area of coal resource, the mining disturbances in the mining face can easily induce mine water inrush accidents, seriously threatening the safe mining of coal resources in China. Mine water disasters are mainly caused by the joint action of rock mass rupture and mine water seepage. The research results show that the parameters such as the longitudinal and transverse wave time, amplitude, frequency, and other microseismic signal parameters can effectively characterize the fracture location and intensity, as well as the source mechanism of rock mass. The parameters such as resistivity, excitation current and self-potential in geoelectric field signals can effectively characterize rock mass seepage evolution process. The characteristics of microseismic field indicate the formation of permeable channels, while the characteristics of geoelectric field indicate groundwater seepage. Therefore, the coupling of microseismic and electrical method has the function of monitoring and early warning for the development process of mine water hazards, which can accurately capture three elements of water hazards including water inrush channel, water source location and seepage process formed in the process of mining failure. It reduces the multiple solutions of a single geophysical method, and improves the monitoring accuracy of water disaster, which is of great significance to the prevention and control of water in coal mines. At present, the microseismic and electrical coupling monitoring technology has begun to be applied in the real-time dynamic monitoring of water hazards in coal mines. Breaking through the limitations of traditional microseismic and electrical data collected independently, the research group has developed the first coal-certified microseismic and electrical coupling parallel monitoring system. With the microseismic field and geoelectric field parallel acquisition base station as the core, this system integrates the passive source micrvoseismic wave field and active and passive geoelectric field. By connecting the mine Internet of Things, the acquisition control, transmission and cloud storage of the remote data are realized. Its integrated network server host can connect multiple acquisition base stations, so as to realize the optimal arrangement of the multi-field observation system in the limited space of the underground and borehole with the separation of microseismic sensor, current electrode and potential electrode while parallel acquisition. It can obtain the spatial and temporal cloud map of microseismic event density and energy level distribution, resistivity distribution and self-potential distribution to monitor and predict the three elements of water hazards. The microseismic and electrical coupling monitoring technology still needs more research particularly in intelligent identification and location of microseismic events, three-dimensional resistivity inversion of geoelectric field and self-potential seepage inversion. Combined with the microseismic and electrical data sets of parallel monitoring, the joint inversion of microseismic and electrical data and intelligent monitoring and early warning method need to be further studied. As a new method of active early warning and monitoring of mine water disaster, the microseismic and electrical coupling monitoring technology will play an important role in the construction of intelligent mine in China.
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