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As a disaster-bearing body, coal mines are vulnerable to the threats of flood disasters and are prone to serious impacts of floods. Floods will not only directly lead to flooding accidents and industrial square destruction, but also indirectly induce abnormal water gushing underground, water permeability, groundwater pollution and other chain disasters. In order to quantitatively assess the risk of coal mine flood accidents caused by flood disasters and strengthen the prevention and control of coal mine flood disasters. Based on the classic theory of three elements of disaster risk science: disaster-causing factors, disaster-pregnant environment, and disaster-bearing body, and the current situation of coal mine flood disaster prevention and control, the investigation index system of flood disaster prevention in coal mine is constructed, and the risk assessment model for flood disaster-induced coal mine water disaster accidents was established, and the application was verified in a coal mine in Tongzi County of Zunyi City. The research shows that the risk assessment of flood-induced coal mine water disasters is a comprehensive assessment of the system risk based on the assessment of the risk of disaster-causing factors, the stability or sensitivity of disaster-pregnant environment and the vulnerability of disaster-bearing body. The time distribution, spatial distribution and intensity of disaster-causing factors are considered in the hazard evaluation of disaster-causing factors. The stability evaluation of disaster-pregnant environment is to evaluate the sensitivity of disaster-pregnant environment to disaster-inducing factors by considering terrain, water system and other factors. The vulnerability of hazard-affected body is determined by two factors and one is the level of flood disaster prevention. The higher the level of prevention is, the lower the vulnerability of hazard-affected body is. The other is the number of people and assets exposed to the disaster-causing factors in the disaster-pregnant environment. And the greater the number is, the higher the vulnerability of the disaster-affected body is. Through the application of the proposed risk assessment model in this Coal Mine, it can be concluded that the risk level of flood-induced coal mine water disasters and accidents in this Coal Mine is low risk. In this paper, the establishment of risk assessment model provides a method for quantitatively evaluating the risk of coal mine water disaster caused by floods. It can provide a new reference for the prevention and control of flood disasters in coal mines.

As an important basic energy and industrial raw material in China, the safe mining of coal is the key to ensuring the national energy security and supporting the stable development of economy and society. With the gradual depletion of shallow coal resources, deep mining has gradually become the new normal of coal resource development in China, and the risk of coal- rock dynamic disasters has risen, which seriously restricts the safety and efficiency of coal mining, and has caused adverse effects on the sustainable development of coal industry. Accurate and reliable monitoring methods are considered as the prerequisite for the prevention and control of coal-rock dynamic disasters. Geophysical methods are widely used in the early warning of coal and rock dynamic disasters by sensing the acoustic, electrical, magnetic and other physical signals released during the deformation and failure process to retrieve the damage and failure state of coal and rock mass. Among those methods, the electromagnetic radiation method is a non-invasive, non-destructive, real-time and strong precursory technique suitable for the development requirements of mine informatization and intellectualization. Therefore, the development of electromagnetic radiation monitoring technology is of great significance for the prevention and control of coal and rock dynamic disasters and can provide important technical support for the construction of intelligent mines. The research achievements of electromagnetic radiation theory and technology are summarized in three aspects: experimental phenomena, mechanism models and technical methods. The discovery process of electromagnetic radiation phenomenon is reviewed. The signal characteristics, influencing factors, electromechanical coupling effects and other electromagnetic radiation characteristics of coal-rock are analyzed. According to the correlation between typical electromagnetic radiation mechanism models, stress action and crack propagation process, a classified review is made. The existing coal and rock electromagnetic radiation monitoring and early warning equipment and technical methods are then briefly introduced. On this basis, the new progress made in recent years is described in detail, including the research on vector characteristics of electromagnetic radiation, micro-scale verification of electromagnetic radiation mechanism, and electromagnetic positioning technology of coal-rock fracture. It summarizes the two current theoretical and technical research bottlenecks that the mechanism is not fully revealed and the location of disaster-prone areas cannot be achieved. Finally, a new target for the future development of electromagnetic radiation theory and technology is proposed.

Mining is one of the key safety production industries that are seriously affected by earthquake disasters and prone to disasters. After many earthquakes such as “Tangshan earthquake” and “Wenchuan earthquake”, there have been serious disasters such as shaft and roadway engineering damages and sharp increase in water inflow, resulting in varying degrees of casualties and economic losses. Aiming at the lack of impact assessment methods of earthquake-induced coal mine secondary disasters, based on the theories of earthquake disaster, safety engineering and system science, and taking the mine lifeline system as the main line, this paper studies and proposes a comprehensive impact assessment method of earthquake-induced coal mine secondary disasters, which is as follows: firstly, the possibility of earthquake-induced coal mine secondary disasters in coal mines is evaluated from the level of earthquake disasters in the area where the mine is located, the risk of earthquake-induced coal mine secondary disasters, the disaster caused by coal seam gas occurrence, the disaster caused by hydro-geological conditions, and the standard setting of earthquake disaster bearing body; secondly, the severity of the consequences of earthquake-induced coal mine secondary disasters is evaluated from three aspects: casualties, economic losses and social impact of disasters; finally, the risk level of coal mine disaster induced by earthquake is determined by constructing the risk level matrix of mine disaster bearing body. The assessment method covers many factors, such as the current situation of pre-disaster fortification, the level of earthquake disaster at the time of disaster, the ability of post disaster emergency disaster reduction and relief, and realizes the full coverage of all key influencing factors before, during and after disaster.

In order to give an accurate warning of coal and gas outburst disaster, a triaxial compression wave velocity test system of coal and rock with gas outburst was built. The coupling relationship between the axial pressure, confining pressure, the gas pressure and wave velocity of coal and rock with gas was studied under the laboratory conditions, and the mathematical model of wave velocity and pressure was established. The results show that: when the load of the sample is constant, with the increase of the gas pressure, the longitudinal wave velocity will decrease sharply at the beginning, and then tend to be stable, showing a linear negative correlation; when the confining pressure and the air pressure conditions are constant, the wave velocity of the sample will increase rapidly after the axial pressure is applied at the beginning, and then the wave velocity tends to be flat and increases linearly, showing an exponential function relationship; when the air pressure and the confining pressure strip, with the increase of confining pressure, the longitudinal velocity of the specimen increases uniformly and linearly, and the mathematical model fitted by the three test results has a high correlation coefficient.

A multisignal nanosecond synchronous acquisition system to measure acoustic emission (AE) and electromagnetic radiation (EMR) generated during the process of loading and failure of coal and rock samples is established. The correlation between the energy of the AE and EMR signals and the loading stress of outburst coal-rock samples was studied, and the characteristics of the AE and EMR signals during the process of loading and fracturing the outburst coal and rock samples were analyzed. The results show that (1) before the failure of the outburst coal and rock samples, the fluctuation of the AE and EMR signals is the largest, with the same rising and falling trend, and the intensity is not strictly positively correlated, with the phenomenon of low EMR when the AE intensity is high; (2) the EMR and AE deviation degree and frequency exhibit a good response to coal and rock fracturing. The correlation between EMR and stress drop is stronger than that of AE, and the AE signal is richer than the EMR signal. The results show that it is feasible to develop combined AE and EMR early warning technology to improve the early forecasting accuracy of coal and gas outbursts. [ABSTRACT FROM AUTHOR]