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In order to effectively solve the problems of independent construction of various systems in the existing coal industry, lack of sharing of multi-system data, low utilization of intelligent analysis and data mining, this paper uses the Internet of Things, big data, artificial intelligence and other information technologies, and on the basis of in-depth integration of coal mine safety management business, we proposed the construction scheme of the whole process traceable coal mine safety intelligent management and control cloud platform, focusing on the analysis of risk management and control, hidden danger trouble shooting, team task processing business processes such as violation correction. The platform realizes the storage, integration and analysis of multi-source heterogeneous monitoring data through the data center, integrates the nine subsystems involved in coal mine safety management into the safety intelligent management and control platform, and uses the data to share a chart for collaborative management and control and effective analysis and display of data. The application results show that the platform has realized coal mine data fusion, collaborative control, business linkage and decision-making, and has a good effect in improving safety control efficiency, reducing control costs and maximizing enterprise interests.

Xinzhuang Coal Mine is a typical kilometer-deep rockburst mine in the Ningzheng mining area of China Huaneng Group, which is still in the capital construction period. At present, there are a few studies on the rockburst mechanism and prevention of this mine. In order to explore the occurrence mechanism and main influencing factors of rockburst under the complex geological conditions of large buried depth, thick topsoil, and hard overburden in Xinzhuang Coal Mine, this paper, based on the analysis of the basic geological data of the mine, deeply explores the comprehensive disaster factors of Xinzhuang Coal Mine; then, uses the analytic hierarchy process to carry out quantitative analysis of each disaster factor, and finally, it obtains the impact type and occurrence mechanism of the mine. Through research, it is found that the main disaster factors of Xinzhuang Coal Mine are mining depth, coal seam thickness, coal seam thickness change, tectonic stress field, hard overburden, roadway layout, bottom coal reservation, and tunneling activities. The key to the process of the rockburst disaster in Xinzhuang Coal Mine is the superimposed effect of static and dynamic loads on the roadway surrounding the rock system. The potential rockburst type during excavation and mining is the “high static and dynamic load disturbance” type.

With the background of gangue rib formed by fine sandstone roof of 6302 working face in Baoshan Coal Mine, the field measurement method of bulking coefficient and its influence on roof deformation of roadway are studied. By analyzing the mechanism of bulking coefficient and combining with engineering practice, the model of measuring bulking coefficient by natural calibration alignment method is established and the method of measuring broken expand coefficient in field is confirmed. And the field measurement shows that there are three stages of roof from collapse to compaction in goaf: the bulking coefficient decreases from 1.83-1.88 to 1.37-1.42 in rapid compaction stage; and in the initial stable stage, which slows down to 1.35 to 1.39. Then in the stage of slow compaction, and the change value of coefficient of fragmentation and expansion is less than or equal to 0.01. Furthermore, there is a certain correlation between the deformation law of roadway surrounding rock and the variation law of gangue bulking coefficient in goaf, which also has three sections, and the final movement amount of roadway roof and floor is 296 mm and 135 mm respectively. According to the gangue bulking coefficient in goaf and the surrounding rock deformation law of roadway, temporary reinforcement support is needed in the roadway during the gob-side entry retaining, and the supporting distance shall be at least 120 m.

The 110 mining method is a high-efficiency entry-retaining technology without coal pillars or filling materials. At present, there is no precedent for its application in the Huaneng Group. In order to introduce this technology, it is planned to carry out experimental application research in the Yuwang NO.1 Coal Mine of the Huaneng Diandong mining area. The Yuwang NO.1 Coal Mine is a typical coal and gas outburst mine with a coal seam group. In view of the introduction of the 110 mining method under these conditions, first, the geological conditions of the Yuwang NO.1 Coal Mine in the Huaneng Diandong mining area are analyzed, the geological characteristics of the test mining face are summarized, and the practical feasibility of the 110 mining method is analyzed according to the geological characteristics of "one soft, one low, two high, and two complex". Then, according to the engineering experience, calculations, and analysis, the key parameters of roof cutting of the test mining face in the Yuwang NO.1 Coal Mine are obtained, and with the help of a numerical simulation, the roof-cutting height, the roof-cutting angle, and the blasting parameters are numerically simulated and analyzed. The roof-cutting key parameters of the test face are obtained as follows: the roof-cutting depth is 7 m, the roof-cutting angle is 15°, and the blasting method is continuous hole blasting with 500 mm spacing. After that, according to the coal and gas outburst and the occurrence conditions of coal seams in the Yuwang NO.1 Coal Mine, a variety of gob closure design schemes and gob gas drainage design schemes are put forward, and the field effect investigation scheme is given. After the tunnels and open-off cut of the test coal mine's first mining face are connected, under the guidance of the above research results, the field blasting test and the 110 mining method entry-retaining test are further carried out to verify the rationality of the design of the roof-cutting parameters and the feasibility of the gangue wall closure and gas drainage design. Furthermore, in the process of the field practice, continuous research is carried out on the stope pressure law and the adjacent layer gas drainage technology under the 110 mining method, and finally, the 110 mining method application technology system in the Diandong Mining Area is formed. [ABSTRACT FROM AUTHOR]

The first weighting control is one of the difficult problems that cannot be avoided in the safe and efficient production of longwall mining face. To optimize the existing pressure releasing technology of open-off cut, the open-off cut roof cutting pressure releasing (OCRCPR) technology is put forward on the basis of roof cutting pressure releasing gob-side entry retaining (RCPRGER) technology. Firstly, the mechanism of the technology and the design method of related key parameters are summarized. Then the pressure releasing effect of OCRCPR and the stress environment change under this technology are analyzed by mechanics calculation and numerical simulation, respectively, which verify the feasibility of the OCRCPR technology from the theoretical level. Finally, a test mining face is taken as an example to implement the field test. The field test results show that the OCRCPR can effectively shorten the first weighting step and weaken the first weighting strength and has a good pressure releasing effect. [ABSTRACT FROM AUTHOR]

In order to mitigate the risk of roof-dominated coal burst in underground coal mining, horizontal long borehole staged hydraulic fracturing technology has been prevailingly employed to facilitate the weakening treatment of the hard roof in advance. Such weakening effect, however, can hardly be evaluated, which leads to a lack of a basis in which to design the schemes and parameters of hydraulic fracturing. In this study, a combined underground-ground integrated microseismic monitoring and transient electromagnetic detection method was utilized to carry out simultaneous evaluations of the seismic responses to each staged fracturing and the apparent resistivity changes before and after all finished fracturing. On this basis, the comparable and applicable fracturing effects on coal burst prevention were evaluated and validated by the distribution of microseismic events and their energy magnitude during the mining process. Results show that the observed mining-induced seismic events are consistent with the evaluation results obtained from the combined seismic-electromagnetic detection method. However, there is a limited reduction effect on resistivity near the fractured section that induces far-field seismic events. Mining-induced seismic events are concentrated primarily within specific areas, while microseismic events in the fractured area exhibit high frequency but low energy overall. This study validates the rationality of combined seismic-electromagnetic detection results and provides valuable insights for optimizing fracturing construction schemes as well as comprehensively evaluating outcomes associated with underground directional long borehole staged hydraulic fracturing.