This paper takes the gas cabin in the utility tunnel in the Xuwei District of Lianyungang as the study object. Based on the computational fluid dynamics (CFD) theory, a simulation model of the gas cabin in the utility tunnel is established. The propagation law of methane leakage and diffusion and the characteristics of methane explosion shock wave propagation were simulated under different conditions of the gas cabin. These conditions are the presence or absence, spacing and height of the air baffle. The results show that: (1) the gas baffle can limit the propagation of methane at the top of the gas cabin and slow down the velocity of diffusion so as to increase the concentration of methane near the baffle and speed up the time for the monitor to reach the alarm concentration; (2) the first peak pressure and the second peak pressure generated in the middle of the gas cabin are smaller than that when the gas baffle is installed. The gas baffle has the function of blocking the propagation of shock waves. However, due to the installation of the gas baffle, the superposition of the shock wave will make the pressure surge at the gas baffle; and (3) combined with the simulation results, it is recommended that the gas baffle spacing is not less than 50 m and the height setting is not greater than 0.5 m.

In order to study the dynamic characteristics and microseismic distribution in the mining process of roadway with high gas and wide coal pillar, combined with the two dynamic events of N2105 working face in Yuwu Coal Industry, theoretical analysis and field measurement research were carried out. According to the theory of structural mechanics and geomechanics, the causes of dynamic appearance are analyzed. Combined with the specific situation, the influence of mining depth, coal pillar width, gas pressure, and content on the dynamic performance is analyzed. Stress monitoring and microseismic monitoring are carried out on one side of coal seam. The results show that, with the increase of the mining distance, the backside roof of the goaf is prone to unbalanced fracture due to the lack of lateral stress, and the impact pressure generated is used for the reserved protective coal pillar behind the goaf, causing the floor heave of coal seam. The combined stress generated by the anticlinal structure below the working face interacts with the abutment pressure of the working face to produce superposition effect, which promotes the occurrence of dynamic appearance. The critical depth of rock burst in Yuwu Coal Industry is about 600m. The increase of coal elastic energy caused by roof subsidence is more uniform with the increase of coal pillar width. The decrease of gas pressure in coal seam promotes the rock burst disaster. The vertical stress of coal seam at one side of the working face shows different evolution characteristics along the trend and strike. The vertical stress of coal seam in the lateral range of 53 m is adjusted to different degrees and tends to be stable until 300 m behind the working face. The active microseismic area in the middle of the working face was located 50 m in front of the working face, and the microseismic activity continued to 30–50 m behind the working face. The active microseismic area at the side of the roadway was located 30 m in front of the working face, and the microseismic activity continued to 100–180 m behind the working face. The inflection point, where the stress in the elastic area of coal pillar increases sharply, corresponds to the active microseismic area, which indicates that the dynamic characteristics in the mining process of roadway with high gas and wide coal pillar are related to the distribution law of microseismic. This study has a certain guiding significance for optimizing the width of reserved coal pillar, monitoring the coal seam stress/microseismic, and understanding the dynamic disaster of coal and rock under complex conditions.

To optimize the support performance of rock bolts in high-stress environments, this study employs the ANSYS (Version 2022 R2) finite element numerical simulation method to systematically investigate the influence of bolt geometrical parameters (rib spacing, rib height, and bolt diameter) on the stress state of the anchoring system. A bolt–resin–sleeve model was established to analyze Mises equivalent stress distribution and peaks under a 150 kN pull-out load. The simulation results indicate that a rib spacing of 36 mm effectively promotes the diffusion of pre-stress into deeper regions, with peak stress in the bolt rod and resin ring increasing by 34.42% and 61.64%, respectively, compared to a spacing of 12 mm. Further increase in rib spacing provides limited enhancement in peak stress. A rib height of 1.0 mm achieves optimal system performance without excessively compromising the interfacial stress level. Increasing the diameter to 22 mm raised peak stress in the bolt, sleeve, and resin by 14.19%, 30.48%, and 50.77%, respectively, compared to 18 mm, balancing load capacity and material use efficiently. The optimal parameter set (36 mm spacing, 1.0 mm height, and 22 mm diameter) was validated in a field trial in Zhongmacun Mine’s 3903 East Transportation Bottom Drainage Roadway. Monitoring recorded maximum roof subsidence of 102.9 mm, stabilizing within 25 days (daily deformation < 0.2 mm), confirming the excellent performance of the bolt support system with this parameter combination in high-stress roadways. This study provides a theoretical basis and engineering reference for the optimal design of high-performance rock bolts.

In order to scientifically guide the water-preserved mining of the coal seam floor and make up for the shortcomings in the conventional evaluation of water blocking performance of the coal seam floor, according to the system resilience theory, the difference between the vulnerability and resilience of the coal seam floor is analyzed, and three elements and nine indicators for evaluating water resistance toughness of the coal seam floor are determined. In the evaluation process, first of all, the maximum difference normalization method is used to conduct a dimensionless analysis of quantifiable indicators to determine the importance of the corresponding indicators, and the AHP software yaahp10.1 is used to determine the weight vector of each indicator. Secondly, the single-factor membership degree is determined according to the single-factor resilience grade classification criterion and membership function and finally combined with the weight vector for fuzzy synthesis calculation and comprehensive evaluation. The model is applied to a specific project. Research has shown that in the water hazard threat area of No. 10 coal seam floor in Jiegou Coal Mine, Anhui Province, the performance of system vulnerability elements is weak, the performance of system recoverability elements is better, and the performance of system adaptability elements is extremely poor. From the perspective of the whole life cycle, determining the treatment target area, optimizing the rock formation modification and repairing materials, and enhancing the water resources carrying capacity can improve the water resistance toughness of the coal seam floor. Related conclusions verify the effectiveness of the evaluation model. Furthermore, an optimized strategy for coal seam floor water retention mining is proposed: the technology system of water-preserved mining for coal seam floor contains 3 stages and 3 detections, which provides a scientific basis for the in situ protection of high-pressure limestone water from coal seam floor.