Search

Based on the geological condition of Luohe Formation sandstone aquifer above the deep working face of 4# coal in Gaojiapu Mine, Binchang Mining area, the relationship between aquifer and dynamic disaster breeding is discussed. Firstly, the formation and its setting condition of the aquifer above 4# coal seam are introduced. Based on field water inflow monitoring data, we examined the relationship between the resistance of the support and the change of water inflow. The temporal and spatial correlation between micro seismicity and water movement is analyzed and identified, which will offer significant value for the early-warning of the dynamic hazards and water inrush. We expound the dynamic and static load of confined water movement on the working face after the increase of water inrush, and point out that it is important to pay more attention to the dynamic disaster risk of the working face after the water surge.

In view of stress concentration, roadway deformation, rock burst and difficult support in the mining of the underlying coal seam under the residual coal pillar, we uses theoretical analysis and numerical simulation to analyze the stress distribution law of 8# and 9# coal seams and the stability of roadway under the disturbance of residual coal pillar in overlying 5# coal seam in a mine of Hebei. The research shows that the stress of the residual coal pillar after bearing the load presents the shape of “double peak”, “saddle”, “trapezoid” and “single peak” from the middle according to the width of the coal pillar. The stress concentration is higher in the irregular part of coal pillar, which has a great influence on the disturbance range of floor coal seam. The peak stress of the residual coal pillar is 52 MPa, and the stress transmitted to the underlying coal seam reaches 44 MPa, which is 2.2 times of the original stress. After the excavation of the service roadway, the stress is 37 MPa, which is 1.8 times of the original stress. Finally, the roadway under the residual coal pillar is controlled by strengthening support and relieving pressure of surrounding rock, so as to ensure the safety and stability of the service roadway.

Aiming at the problem of the unclear rock burst generation mechanism and anti-impact measures of a large roadway through a coal seam in a deep panel area, taking the rock burst of a large roadway in the first panel area of Gaojiapu Coal Mine as the engineering background, this paper adopts the comprehensive research methods of theoretical analysis, experiments, numerical simulation, fragmentation fractal analysis, and field monitoring, to discuss the mechanical characteristics of the loading process of the assemblage and the energy transfer law and its difference in the deformation and failure process. The possibility and strength of the impact failure of coal under the grip of rock masses with different stiffness are related to the γ value. The smaller the γ value is, the higher the impact possibility is, and the more severe the impact degree is. The assemblage under the grip of soft rock is more prone to system instability. Energy relief and impact reduction are adopted to reduce the post-peak stiffness and elastic strain energy of the coal body in a short distance, avoid the energy transfer and concentration of the roadway surrounding the rock system under the disturbance of a long-distance dynamic load, and reduce the likelihood of impact pressure occurring and the extent to which an impact manifests. [ABSTRACT FROM AUTHOR]