Excavation‐induced rock failure and deformation near an underground opening boundary is closely associated with the intermediate principal stress, strain softening and rock mass dilation. By combining theoretical analysis and numerical simulation to explore the mechanical evolution of the roadway surrounding rock during excavation. The elastic–plastic criterion solutions for surrounding rock stress, displacement, and the plastic zone of a circular roadway were deduced by including the intermediate principal stress, strain softening and rock mass dilation, based on the Drucker–Prager criterion and the nonassociated flow rule. Furthermore, ABAQUS finite element software was utilized for numerical simulations to scrutinize the influence of mechanical parameters on stress redistribution, surface displacement, and plastic range. The results of the numerical simulations verify the reliability of the theoretical analysis and affirm the high consistency of the results with the theoretical solution. The research findings indicate that the strength of surrounding rock is significantly influenced by the intermediate principal stress, and the deformation and failure of rock mass are primarily impacted by rock mass dilation, while strain softening mainly affects the thickness of the fractured zone. Moreover, the study reveals that enhancing the residual strength of the surrounding rock can improve its resistance to deformation and failure. Furthermore, the excavation of the roadway is observed to increase the original rock stress in the surrounding rock, but increasing the ground support strength effectively controls the deformation and failure of surrounding rock. Ultimately, the research outcomes offer valuable references for engineering calculations and ground support design of surrounding rock in deep roadways.

In view of the problems of large deformation of surrounding rock, high in-situ stress, and serious soft fracture of rock stratum in deep soft rock roadway, the instability deformation failure mode of deep soft rock roadway is analyzed theoretically. The FLAC^3D software is used to establish a three-dimensional numerical model of surrounding rock damage under load, and to study the displacement, stress, and plastic expansion process of damage and failure evolution in the surrounding rock of the roadway. The mechanical response mechanism of deep soft rock roadway surrounding rock bending deformation, elastoplastic transformation, and unloading failure is verified by MATLAB numerical analysis, and the space-time evolution characteristics of soft rock deformation and failure are revealed. The results show that the surrounding rock of deep soft rock roadway has many failure modes, such as obvious displacement and deformation, high stress concentration, and intensified plastic transformation in the surrounding rock. The vertical stress in the surrounding rock is concentrated at the direct top and bottom, and the horizontal stress is concentrated at the roadway side and bottom; plastic deformation and failure first appeared at the roadway side, and then extended to other parts. The research conclusion provides an important reference for surrounding rock control and roof management of high-stress soft rock roadway under deep excavation disturbance.

Coal is the primary source of energy in China’s energy structure system. With the large‐scale mining of mineral resources, a large amount of mine water will be produced in the process of development, construction, and production, which will pollute and damage the ecological environment of mine water. At present, China vigorously advocates coal revolution, implements low‐carbon economy, and carries out clean production of energy development and utilization. Green mining, precision mining, and other strategic ideas have been applied to mine development to guide production practice. This paper does an in‐depth analysis of the physical, chemical, biological, and environmental characteristics of mine water, puts forward the basic classification of mine water, and points out the characteristics of environmental hazards of mine water. Aiming at different types of mine water, such as mine wastewater, drainage water, goaf water, mine water with suspended solids, high salinity mine water, acid mine water, and mine water with special pollution, the paper puts forward the mine water treatment and resource utilization technology with different characteristics and strong pertinence. On this basis, the comprehensive treatment and development direction of mine water in the future are prospected.

Aiming at the problems of stress concentration, large deformation and serious damage in surrounding rock of deep roadways under excavation unloading disturbance conditions, the micro and macro mechanical properties and damage patterns of deep rock internal structure deformation instability were analyzed by combining rock mechanics tests with XRD, SEM and AE test technology; a zonal distribution model for damage of surrounding rock was established using elastoplastic theory and yield strength criteria, with derived expressions for stress–strain, displacement, and radius of each zone; FLAC^3D was used to investigate the spatiotemporal evolution of surrounding rock under different influencing factors. Results show that: ①Rock deformation and destabilization are closely related to the microstructural properties. There are numerous tiny cracks inside the rocks, which tend to expand and interconnect under external forces, leading to rock fracture. ②Rock damage progresses through five stages: initial compression, linear elastic deformation, nonlinear crack generation, post-peak strain softening and destruction. Rock fissure destabilization damage process has irregular, discontinuous, nonlinear time sequence evolution characteristics. ③The circle damage model of broken unstable zone, plastic softening zone, plastic fracture zone and elastic deformation zone was established. The peripheral rock disturbance destabilization has the distribution characteristics of zonal damage, stage development, and strong–weak evolution. ④Residual strength and original rock stress have significant influence on stress, displacement and plastic zone, and play the main control role on deformation of surrounding rock. The results provide theoretical support for disaster prevention and stability control of surrounding rock in deep roadways.

Coal seam mining causes movement and deformation of the overlying rock mass and ground surface, directly resulting in serious damage to the surface construction facilities. To investigate the deformation mechanism and characteristics of the overlying rock mass, three-dimensional numerical simulation and model test are carried out on an open-pit mine slope. The results show that the sliding instability characteristics of the slope can be identified based on the numerical analysis. Coal mining affects on the deformation characteristics of the overlying rock mass near the inner dump. The closer to the slope boundary, the greater the subsidence of overlying rock mass. The maximum displacement occurs near the inner dump. The slope mining has great influence on the deformation characteristics of inner dump. Moreover, the damage process of overlying rock mass can be further studied via the model test. After coal seams mining out, the overlying rock mass occurs overall settlement failure. There is a large difference between the lower end side of working face and the upper end side at the caving angle of roof. This work can provide a basis for the safe operation of coal mine disaster prevention and mitigation.

Extraction of gas from low-permeability thick coal seams poses challenges globally, attributed to low extraction efficiency, limited enrichment content, and extraction complexities. Investigating static fracturing in low-permeability thick coal seams holds substantial engineering significance and practical utility. This research delves into the current conditions in the Western region, characterized by low gas permeability and challenging extraction in thick coal seams. Through the utilization of FLAC^3D and COMSOL, simulation schemes are devised to analyze the influence of borehole parameters on fracture efficacy, elucidating the mechanisms by which external loads and internal gas pressure impact coal seam permeability. Field monitoring tests are employed to evaluate and model gas extraction enhancement via borehole positioning. The results suggest that the application of a static fracturing agent inducing 40 MPa expansion stress, along with a 75 mm borehole diameter and 0.5 m spacing, effectively fractures low-permeability thick coal seams. The spacing between extraction and fracturing holes adversely affects gas extraction efficiency due to the limited range of static fracturing. Field experiments demonstrate that static fracturing significantly improves gas extraction from low-permeability thick coal seams, resulting in a twofold increase in average gas extraction purity post-fracturing. This study establishes a robust theoretical foundation for optimizing gas extraction and mining activities in challenging low-permeability thick coal seam environments.