The pressure relief of coal pillars in close-distance multi-coal seam goaf is a complex engineering problem with the characteristics of “dynamic mine pressure”. Hence, this paper studies such problems. First, the influence factors of the coal pillar in the goaf on the mine pressure of the mining face of the lower coal seam under this condition were theoretically analyzed, and it was concluded that vertical stress is the most important element, followed by horizontal stress. Next, a physical similarity simulation experiment was designed to study the stress distribution law of the coal pillar floor in the goaf before and after pressure release and the damage depth. Finally, a technology and monitoring method for coal pillar blasting pressure alleviation in goaf were introduced and implemented in engineering practice. After the pressure is alleviated, the surrounding rock stress of the lower coal seam mining face is redistributed, and the vertical stress is decreased by 20%. The adjacent rock’s deformation is improved. This technology’s cost and safety advantages are extraordinary and helpful for mining coal seams over close distances.

Because of the control problems caused by the non-uniform load of the roof of the working face when the shallow coal seam is mined under the condition of gully terrain. In this study, theoretical analysis, similar simulation, and field measurement methods are comprehensively used to incorporate gully topographic factors into the study of roof structure control, and a mechanical model of roof structure under non-uniform load is constructed. The interaction relationship between “powered roof support-rock mass” during the period of periodic pressure is analyzed, the corresponding model is established, and then the calculation equation of support resistance for controlling the sliding instability of the roof structure passing through the gully is derived. Taking the first mining face of Shaliang Coal Mine as the engineering background, reasonable support resistance is given based on the above research results. Through similar simulation experiments, the average weighting steps in the mining stage of downhill, gully bottom, uphill, and convex landforms are 19 m, 30 m, 14 m, and 15 m, respectively. The periodic weighting step in the gully bottom stage is the largest and the uphill mining stage is the shortest. Verified by field measured data, the derived equation is accurate and reliable. The research results enrich the roof control theory of shallow coal seam mining, provide key technical support and practical guidance for coal mining under similar geological conditions, and help to ensure coal mine safety production.

The thin spray-on liner is an inorganic polymer product that has been widely used to support mine perimeter rock roadways, but it is mainly used in metallic hard rock roadways with high rock strength and is less used in roadways affected by roadway corrosion and weathering in shallowly buried coal seams. Therefore, this study studies the thin spray-on liner support technology under such geological conditions. First, the causes of anchor support failure in this condition are analyzed, and it is concluded that alkaline ionized water corrodes the anchor rods, and chloride ions in the water play a role in accelerating the degree of anchor rod corrosion. Next, microscopic testing was used to determine the content of weathering and swelling minerals contained in the roof rock and the development of tectonic fissures. Third, the loosening circle of the surrounding rock is theoretically calculated and used as a basis to design the anchor mesh rope support parameters for the roadway. Finally, the construction process of a thin spray-on liner anticorrosion and antiweathering support technology is introduced. This technology improves the anchor force environment of anchor rods while incorporating anchor rods (ropes)—rock—metal mesh into the support system to play a coupling support role. On-site monitoring is performed to derive the optimum thickness of the spraying layer in different environments. At the same time, the deformation of the roadway surrounding rock and the anchor force can be improved to meet the requirements of anticorrosion and antiweathering and tighten the roadway surrounding rock. Compared with concrete support technology, the economic and environmental benefits of this support technology are apparent, and it helps to promote the application in shallowly buried coal seam mines.

Mining-induced fractures resulting from shallow coal seam extraction in the loess gully region of China are complex and variable, presenting critical hazards including water and sand inrush, as well as air leakage, all of which severely endanger operational safety. This study aims to examine the spatiotemporal evolution characteristics of mining-induced fractures in shallow coal seams within China’s loess gully region. Focusing on the Shenfu mining area, a combination of theoretical analysis, numerical modeling, and physical similarity simulation is employed to investigate mining processes and fracture development in shallow coal seams within loess gully. Findings indicate that the loess gully surface contains highly concentrated stress regions, distributed both horizontally and vertically. Mining-induced fractures along the slope primarily experience tensile failure, and most are ultimately closed due to the rotary extrusion exerted by the slope; The evolution of mining-induced fractures exhibits three distinct periodic development patterns: “half cycle” (inoculation—expansion—stationary), “single cycle” (inoculation—expansion—semi-closed or closed), and “double cycle” (inoculation—initial expansion—initial closure—secondary expansion—secondary closure) within the loess gully region. Through the development of a “rock chain structure” model for overlying strata, the dynamic mechanisms driving the three periodic mining-induced fracture types are individually elucidated. Analyzing the stress state of the “rock chain structure” model under linear loading reveals the instability conditions of the bedrock structure and the fracture types resulting from linear loading. These findings offer both theoretical insights and practical guidance for further research and engineering applications in shallow coal seam mining within loess gully regions.

The slope‐pillar structure is defined as an artificial construction shaped by a surface highwall mining and an underground longwall mining. In order to study the impact of stress variations (induced by the longwall‐mining operations) on the stability of a slope‐pillar structure, No. 30101‐1 working face of Nanliang Coal Mine was selected as the study subject. A series of analysis including physical similar simulation test and the theoretical analysis were conducted to study the movement pattern of the overlying strata in the working face of the slope and the loading and the stability of the pillar column revealing the mechanism of dynamic load instability of nonuniformly distributed load “slope pillar.” A “slope‐pillar” reverse sliding structural model was proposed along with a newly established “slope‐pillar” structural mechanical model and a formula to calculate the boundary width of the protection for the pillar under the extreme balance conditions. According to the study, the width of the protective pillar is designed at 20 m, and the roadway deformation during the working face and the stability of the pillar can satisfy the safety requirement concerning the working face, which further validates the theoretic deduction formula.

The extraction of coal resources can greatly affect surface ecology. This impact is particularly seen in loess gully regions (LGRs), where surface cracks form and expand, threatening land stability and ecological safety. To tackle these concerns, this study combines discrete physical simulation experiments with numerical simulations. It focuses on the 135,201 working face of a typical coal mine in the LGR. A 1:100 discrete physical model is created to simulate surface crack generation and expansion across different mining stages. This model enables the analysis of overburden fissure evolution, surface crack development, and surface movement patterns. The research reveals that the development of surface cracks is jointly influenced by the characteristics of mining—induced overburden pressure and the surface topography. During the second mining stage (the Bottom of the Gully Mining Stage), underground mining has a relatively small impact on the surface. However, in the third stage (the Back of the Gully Mining Stage), the surface is more frequently and severely affected by underground excavation, with the same underground mining distance causing more intense surface disturbance. Numerical simulations are also used to study the failure, stress, and surface movement and deformation of the overlying rock layer in the mining area. Field observations further analyse the initiation, active, and recession stages of surface subsidence in the LGR during coal mining. Calculations of tilt and curvature variations between adjacent measurement points show that surface tilt and curvature changes along the inclination observation line are more regular, with maximum tilt values reaching 61.7 mm/m and 60.8 mm/m. However, variations along the strike observation line are influenced by the complex local topography and geomorphology. Overall, the results offer useful insights for coal mining and surface protection in similar geological settings, especially through the physical model experiments applied in this study.