In recent years, with the rapid development of equipment manufacturing and advances in the research on mine pressure and rock mechanics, large-mining-height comprehensive mechanized coal mining technology has become increasingly widely used in thick-seam mining. On this basis, because the free space extracted is several times that of layered mining, the occurrence of strong ground pressure caused by the violent movement of the basic roof and the low recovery rate of the top coal have become the main problems. In this study, Dong Liang Coal Mine was taken as the engineering background by which to study the three typical movement forms of the basic roof, and the critical fracture conditions of the three forms were obtained through theoretical calculations. The movement result state of the basic roof strata was taken as the different overlying boundary conditions of the top coal to simulate its impact on the recovery rate, to explore the interaction mechanism between the basic roof strata and the top coal, and for use as a theoretical basis to guide engineering practice to improve energy recovery rates and safety efficiency.

Rockburst is globally regarded as one of the most severe and complicated mining dynamic disasters to predict or control. Generally, the occurrence mechanism of rockbursts can be considered as a process of the elastic strain energy accumulation, emancipation, transmission, and occurrence. Tracing to the source, the reasons for large accumulation of elastic strain energy in coal and rock mass are the high stress of the roof layer that loads on the coal and rock masses around the mining space coupling effect with the natural horizontal tectonic stress. In this study, using the minimum energy theory and elasticity theory, the analytical formula for calculating elastic strain energy of the roof cantilever beam structure acting on the coal body load in front of the working face is deduced. Accordingly, we achieved a method of using hydraulic fracturing to improve the roof structure. In detail, we use a high‐pressure jet to cut the cantilever roof structure, which can make a prelocated fracture surface, and then utilize the packers to make sure that the injected high‐pressure fracturing fluid is propagating along the prelocated fracture surface and can cut off the cantilever roof structure eventually to prevent rockbursts in advance. Due to the rockburst occurrence mechanism and the quantitatively elastic strain energy analytical formula, a preconditioning water jet cutting induced fracture surface to create orientation‐controllable hydraulic fracture strategy is proposed to guard against the high hazard caused by the massive elastic strain energy, which accumulated in the coal body in front of the working face and coal pillar.

The clean utilization and green development of coal resources have become a research focus in recent years. Underground hydraulic fracturing technology in coal mines has been widely used in roof pressure relief, top coal pre-splitting, gas drainage, roadway pressure relief and goaf disaster prevention. Different in situ stress types cause great differences in the stress field around the boreholes, the critical pressure of the fracture initiation, and the direction of the fracture expansion trend; in addition, the stress shadow effect generated by the superposition of stress fields between boreholes relatively close together has a mutual coupling effect on the evolution of the stress field, the development of the plastic zone, and the crack propagation of the rock mass. Therefore, an effective method to solve the problem is to establish a mechanical model of hydraulic fracturing in boreholes for theoretical calculation, determine the influence mechanism of the crack shadow effect, and design a numerical simulation experiment of the equivalent stress fluid–solid coupling of hydraulic fracturing under different pore diameters and spacings. In addition, combining rock mechanics and fracture mechanics to analyze the influence of the shadow effect of the stress field between cracks on the evolution of the equivalent stress and the plastic zone is one of the important advances in this paper. Considering the engineering background of the site, the geological conditions and the requirements of general regulations, it is considered that the parameter selection of roof fracturing hydraulic fracturing technology in the Yushen mining area is more suitable when 0.12 m hole diameter and 3.5 m hole spacing are selected.

For a long time, the management of surface structures such as villages and rivers affected by underground coal mining has been a popular and difficult issue in coal mining. With the further tightening of environmental protection requirements, it has become challenging for some underground coal mines that lack the conditions for filling and grouting to ensure the recovery of coal resources while controlling surface subsidence. Furthermore, many such common issues have emerged in the Yushen and Binchang mining areas of Shanxi Province, as well as in several other coalfields, severely constraining the development of coal energy and ecological environmental protection. Research on numerical simulation experiments and theoretical calculations via mechanical models suggests that the presence of multiple thick and hard key strata in the overlying rocks plays a crucial role in controlling surface displacement through the interlayer shading effect. A comparison of three mining methods, namely, fully mechanized top-coal caving with a large mining height (CMTC), longwall mining with a large mining height and full-height cutting (LMHT), and layered fully mechanized top-coal caving (LCMTC), reveals peak surface displacements of 3.818 m (CMTC), 3.649 m (LMHT), and 3.32 m (LCMTC), respectively, and peak vertical stresses of 7.3 MPa (CMTC), 5.9 MPa (LMHT), and 8.3 MPa (LCMTC), respectively. Based on these findings, an artificial buffer layer technology for controlling overlying rock displacement is proposed. This technology has a significant effect on effectively controlling surface subsidence by releasing stress in the overlying rock and provides a theoretical reference and methodological insights for mines with similar operating conditions.

Aiming at the problem of the serious deformation of the mining roadways in the trapezoidal section of the coal mine, the method of combining theoretical analysis and field application is used to study the surrounding rock control method of the trapezoidal roadways. The conformal mapping function of the trapezoidal roadways is calculated by the theory of complex change, and then from the analytical solution of the tangential stress distributed in the surrounding rock of trapezoidal roadways which is under the influence of the bidirectional unequal pressure, homogeneous, isotropic, and elastic rock mass is obtained. Research studies show that the roof‐stress distribution of the trapezoidal roadways is uniform and the confining pressure is small, while the two sidewalls and the floor are opposite. The stress distribution of the two sidewalls and the floor varies greatly, and the stress concentration factor is large. The top corner of the trapezoidal roadways is basically not affected by stress concentration, but the stress concentration coefficient at the bottom corner is relatively large, and reinforcement measures are required in the roadway support. Based on the aforementioned research results, the multisupport scheme of “bolting with wire mesh and anchor cable + W‐type steel belt + joist steel shed support + anchor cable grouting” was proposed to the surrounding rock of trapezoidal roadways with large stress caused by mining influence, thus solving the actual mining problem.

The movement of overburden strata under valley geomorphological conditions presents significant challenges for ground pressure control and the protection of surface ecosystems and aquifers. In this study, geological and boundary mechanical conditions were obtained through field investigation and monitoring, and were subsequently applied in both physical similarity simulation and numerical modeling. The research focuses on two mining sequences—steep gully to deep gully (SG→DG) and deep gully to steep gully (DG→SG)—to analyze the evolution of stress and displacement in overburden strata at different mining stages. A novel approach integrating deep learning techniques was employed to identify and analyze stress-displacement image patterns. Results indicate that when vertical stress is considered, the proportion of high-risk stress zones under the DG→SG method reaches 5.57%, compared to only 3.28% under the SG→DG method. This implies that the probability of stress-related hazards in the SG→DG sequence is approximately 58% of that in the DG→SG sequence. These findings suggest that the SG→DG method offers significant advantages in mitigating ground pressure risks. It is therefore recommended as the preferred mining approach, especially when combined with ground grouting and underground hydraulic fracturing techniques. Furthermore, the study reveals that mining direction is a critical human-controllable factor affecting overburden behavior. By investigating stress redistribution under different mining sequences, this research provides new insights into stress transfer mechanisms in overburden strata, offering theoretical guidance for the safe and efficient extraction of coal resources in complex valley terrain environments.