Rockbursts are serious mine disasters. Through the division of rockburst risk zones, risks can be predicted in advance and measures can be implemented to prevent disasters. In this paper, taking the Hegang mining area as an example, we propose a method for dividing rockburst risk zones based on in-situ stress measurements. First, 24 survey points were established in the Hegang mining area to measure the in-situ stress. Second, based on the in-situ stress measurement data, eight representative prospecting lines were selected to establish a numerical model, and the distribution characteristics of the in-situ stress field at mining elevations of −330 m and −450 m in the Hegang mining area were obtained via the linear differential method. Afterward, division criteria for rockburst risk zones were proposed in accordance with the energy criterion and the minimum energy principle. Finally, the Hegang mining area was divided into rockburst risk zones in accordance with the in-situ microseismic monitoring data and simulation results for the in-situ stress field. Coal seam #3 was chosen as an example to illustrate rockburst risk-zone division in the Hegang mining area considering the division criterion proposed herein, and a rockburst risk zoning map of coal seam #3 in the Hegang mining area was finally obtained. The locations of the five rockbursts that have occurred in coal seam #3 of the Hegang mining area were marked on the risk zoning map and were found to have occurred in the threatened zone. Thus, it was shown that the proposed rockburst risk-zone division method is reasonable. Therefore, the results of this study could serve as a reference for the division of rockburst risk zones.

As the depth of coal mining increases, rockbursts become more severe, and multiple rockburst accidents have previously occurred, seriously affecting coal mine production safety. With the Hegang mining area as the research object and using field measurement and numerical simulation as the research methods, the geological and tectonic characteristics of each impact mine in the Hegang mining area are analyzed to obtain the tectonic stress field distribution characteristics of each mine and the tectonic stress field distribution trend in the Hegang mining area. The maximum horizontal principal stress and the minimum horizontal principal stress on the energy field in the overrun area of the retrieval working face is analyzed via numerical simulation, and the influence trend of the ground stress on the impact ground pressure is finally obtained. Results show that using the typical working face where rockburst occurs as the geological proto-type, the influence of the direction of the ground stress field, the maximum horizontal principal stress and the minimum horizontal principal stress on the energy field in the overrun area of the retrieval working face is analyzed via numerical simulation, and the influence trend of the ground stress on the impact ground pressure is finally obtained. When the angle is 70°~90°, an energy peak in the overrun area of the working face reaches its maximum. The ratio of the minimum horizontal stress to the vertical stress is positively correlated with the energy concentration in the overrun area of the working face, but its change has a minimal effect on the energy distribution in the overrun area of the working face. When this ratio is increased from 0.6 to 1.4, the peak energy of the simulated working face only increases by 8.22%, and the energy concentration area remains basically unchanged.

To investigate the effect of prefabricated borehole diameter on the dynamic response of coal–rock composite specimens, split Hopkinson pressure bar (SHPB) tests were conducted on specimens without a borehole and with borehole diameters of 4, 6, and 8 mm. Twelve specimens were tested, with three specimens in each group, under a nominal impact pressure of 0.3 MPa. The average strain rates ranged from 19.64 to 22.36 s⁻¹, while the peak strain rates ranged from 29.79 to 33.10 s⁻¹. The group-mean nominal dynamic peak strengths of the 0, 4, 6, and 8 mm groups were 92.87, 94.68, 78.34, and 77.60 MPa, respectively. The peak strain and peak secant modulus both exhibited non-monotonic variations with borehole diameter. The corresponding group-mean net absorbed energies were 33.96, 35.60, 32.16, and 33.05 J, respectively, also showing a non-monotonic variation. Across the four borehole-diameter groups, the group-mean fitted fragmentation parameter ranged from 1.95 to 2.06, while the group-mean characteristic particle size ranged from 6.95 to 7.76 mm. The Weibull statistical damage model provided a good descriptive representation of the nonlinear stress–strain response within the selected fitting interval, with group-mean coefficients of determination $R^2$ ranging from 0.9895 to 0.9969. Overall, the load-bearing, energy, fragmentation, and nonlinear deformation responses varied among the tested borehole-diameter groups, and the different response indicators did not exhibit a uniform monotonic dependence on borehole diameter.