Method for preventing and controlling rock burst remained under coal pillar

Abstract

The invention discloses a method for preventing and controlling rock burst remained under a coal pillar, which is used for weakening an upper coal pillar by constructing and drilling a tunnel under a coal pillar and adopting a high-pressure water injection mode to reduce the intensive high stress in the coal pillar. The method comprises the following steps: firstly, grasping the position relationship between a remained coal pillar and the lower working surface to determine a releasing area; then, constructing water injection and drilling in the area, and determining drilling parameters according to the geographical condition and position relationship; grasping the drilling depth when entering the upper coal layer in the drilling constructing process; injecting water by utilizing an emulsion pump station, a high-pressure water injection pipeline and a hydraulic expansion hole packet after drilling is completed, and leading the hole packing position to be in the upper coal layer; and stopping water injection when the water injection time is reached or water injection pressure is unexpectedly reduced. The method can realize direct releasing treatment for a coal pillar remained in a gob, and has the advantages of low construction amount, high safety coefficient, good prevention effect and the like in comparison with drilling release, coal layer burst and other traditional methods.

Description

technical field [0001] The invention relates to a method for preventing and controlling rock burst when excavating under the left coal pillar. This method of prevention and control of rock burst is mainly applicable to the mining conditions of short-distance coal seam groups. When there are coal pillars left in the mining process of the upper coal seam, it will bring high stress concentration to the lower coal seam, which will increase the impact risk. In this case, the rock burst prevention method is carried out. Background technique [0002] For mining areas with multiple coal seams, coal seam group joint mining is an economical and efficient mining method. For rock burst mines, choosing a reasonable coal seam as a protective layer for mining can effectively reduce the coal stress of the protected layer and achieve the effect of pre-pressure relief. However, in the process of mining the protective layer, affected by the geological structure or the occurrence conditions o...

AI Technical Summary

Problems solved by technology

In addition, with the development of shale gas mining, high-pressure water fracturing technology is becoming more and more mature. At present, hydraulic fracturing has begun to be used in coal mines to treat hard roofs, but the process is relatively complicated.

Images