The research on deformation zoning mechanism of tunnel surrounding rock is of great significance for ensuring safe production and disaster prevention in coal mines. However, the traditional deformation zoning theory of tunnel surrounding rock uses the ideal strain softening model as the criterion for judging the zoning type of all tunnel surrounding rock, ignoring the difference between the deformation zoning type of a specific actual tunnel and the basic zoning type of surrounding rock. In order to study the method for determining the actual deformation zoning type of tunnel surrounding rock, the formation mechanism of the actual deformation zoning of tunnel surrounding rock has been revealed. Combined with engineering examples, a method for determining the actual deformation zoning type and boundary stress of specific tunnel surrounding rock has been proposed. The results show that the boundary stress and position of the actual deformation zone are determined by the peak strength fitting line, residual strength fitting line, support strength line, and the position of the circumferential and radial stress relationship lines of each deformation zone. The actual boundary stress of each zone of tunnel surrounding rock is ultimately only related to the basic mechanical properties of the tunnel surrounding rock and the in-situ stress field. The research results can provide reference for disaster management of underground engineering, stability evaluation of surrounding rock, and support scheme design.

Through in-situ stress measurements, stress data were obtained from an auxiliary transportation roadway in a coal mine in Shanxi Province, China. Based on the principles of elastic mechanics and using a generalized plane strain model, the mechanical effects of the in-situ stresses on an idealized roadway were calculated and the distributions of stresses, displacements, and plastic zones determined. Building on this model, the vulnerable zones in the roadway cross section were identified. Ground support specifications were developed and during specification design, comprehensive consideration was given to factors affecting the stability of the rock surrounding the roadway. A scientific and reasonable support scheme was put forward. Practical experience in the coal mine shows the normal forces of anchor bolt and cable, the minimal convergence of roof to floor, and a generally good support in the auxiliary transportation roadway. The support should ensure safe production during its service life. This study provides a new method for designing roadway support systems that can be particularly valuable for high-stress roadways.

Finding effective ways to efficiently drive roadways at depths over 1 km has become a hotspot research issue in the field of mining engineering. In this study, based on the local geological conditions in the Xinwen Mining Area (XMA) of China, in-situ stress measurements were conducted in 15 representative deep roadways, which revealed the overall tectonic stress field pattern, with the domination of the horizontal principal stresses. The latter values reached as high as 42.19 MPa, posing a significant challenge to the drivage work. Given this, a comprehensive set of innovative techniques for efficiently driving roadways at depths over 1 km was developed, including (i) controlled blasting with bidirectional energy focusing for directional fracturing, (ii) controlled blasting with multidirectional energy distribution for efficient rock fragmentation, (iii) wedge-cylinder duplex cuts centered on double empty holes, and (iv) high-strength supports for deep roadways. The proposed set of techniques was successfully implemented in the –1010 west rock roadway (WRR) drivage at the Huafeng Coal Mine (HCM). The improved drivage efficiency was characterized by the average and maximum monthly advances of 125 and 151 m, respectively. The roadway cross-sectional shape accuracy was also significantly improved, with the overbreak and underbreak zones being less than 50 mm. The deformation in the surrounding rock of roadway (SRR) was adequately controlled, thus avoiding repeated maintenance and repair. The relevant research results can provide technical guidance for efficient drivage of roadways at depths over 1 km in other mining areas in China and worldwide.