Hard-roof rock burst control method based on medium property change

Abstract

The invention discloses a hard-roof rock burst control method based on medium property change. The hard-roof rock burst control method based on medium property change comprises the following steps: determining a burst hazard range, and the hazard levels of different sections in the range at first; then starting to blast a coal body step by step from the boundary of the hazard area in the burst hazard range, carrying out pressure relief and loosening on the coal body to modify, enabling the coal body to be exploited in the burst hazard range to form a fluctuation conduction medium with difference, weakening the conduction steep of wave, and reducing the roof pressure impact; and carrying out low-pressure water injection on the interior of a blasting loosening area, and realizing softening with different depths for the coal body, so that displacement change is generated on the fracture line of the original hard roof, irregular fracture occurs, and moreover, the fracture line at a place which is much softened, that is, a place with a higher hazard level, has a farther distance away from a roadway, so that a safer stope is achieved.

Description

technical field [0001] The invention belongs to the technical field of coal mining. Background technique [0002] The geological conditions of deep mines in my country are complex and changeable, and it is easy to cause dynamic disasters such as rock burst. Factors affecting rock burst include structure, buried depth, roof, coal seam hardness, mining factors, etc. Among them, rock burst caused by hard roof occupies a large proportion. Specific gravity, and more destructive. How to control the hazards of hard roof burst is a major technical problem faced by coal mines. Because the coal seam under the hard roof is mined, there is often a suspended roof structure (see figure 1 shown), resulting in large static loads on the trough and the working face, and rock bursts occurred during the mining period accompanied by the fracture movement of the roof. This type of rock burst is called hard roof rock burst. The current prevention and control of rock burst mainly adopts measures...

AI Technical Summary

Problems solved by technology

The current prevention and control of rockburst mainly adopts measures such as mining liberated seams, water injection in coal seams, retaining roadways with broken roofs, strong support, strong pressure relief in coal seams, broken roofs, and broken bottoms. These measures are difficult to completely control the risk of hard roof impacts.

The reason is that these measures are mainly considered from the perspective of changing the pressure of the coal seam, without considering the medium properties of the coal seam itself

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