关键词: 急倾斜巨厚煤层, 掘进巷道, 冲击地压, 卸压, 动静载荷, 多源协同防治策略

Abstract:

To solve the problem of roof deformation in steeply inclined coal seam roadways, this paper took roadway excavation in a steeply inclined coal seam at Wudong Coal Mine as the research object. Numerical simulations were used to investigate the dynamic response of the surrounding rock under dynamic and static loads, determine the propagation characteristics of vibration waves in steeply inclined extra-thick coal seams, reveal the disaster-causing mechanism of rockbursts during roadway excavation in such coal seams, identify multi-source prevention and control targets and key areas during roadway excavation, and develop rockburst prevention and control strategies for roadway excavation in steeply inclined coal seams. The results show that stress waves exhibit a significant reflection effect at the coal-rock interface, and dynamic load disturbance increases the peak horizontal stress of the coal wall to 21.8 MPa, representing an increase of 25%. The degree of damage to the coal and rock in the coal wall and roadway floor is relatively high, indicating that the effects of dynamic loads exhibit obvious directional characteristics. The propagation effects are ranked as follows: floor (2.71 m/s) > coal wall (1.26 m/s) > rock wall (0.69 m/s) > roof. During roadway excavation in steeply inclined extra-thick coal seams, the suspended roof in the goaf and the compressive and prying effects of rock pillars are the primary sources of static loads, while excavation disturbance is the primary source of dynamic loads. The coupling of static stress and dynamic load disturbance is the key mechanism underlying the occurrence of rockbursts. Optimizing the roadway support scheme and implementing technical measures such as large-diameter borehole pressure relief and water-injection pressure relief can effectively reduce the rockburst tendency of the coal and rock, increase the critical stress, and reduce energy accumulation in the surrounding rock. This study provides important theoretical support and a reference for engineering practice in the prevention and control of rockburst under similar geological and mining conditions.

Key words: steeply inclined extra-thick coal seam, excavation roadway, rockburst, pressure relief, dynamic and static loads, multi-source collaborative prevention and control strategy