Pressure relief method for short-distance overlying residual coal pillar

Abstract

The invention discloses a pressure relief method for a short-distance overlying residual coal pillar. The method comprises the following steps that a standard test piece is prepared in a laboratory after sampling, and the width X1 of a crushing zone formed by the influence of primary mining in the coal pillar and the width X2 of a crushing zone formed by the influence of secondary mining in the coal pillar are determined; a hole is drilled upwards in the roadside on the side, close to the coal pillar, of an underlying coal seam roadway on the site, an explosive is filled in the hole for blasting, as the shape of the cross section of the remaining part of the coal pillar approximates to a parallelogram, through the instability quality of the parallelogram, the coal pillar is further damagedunder the action of concentrated load of a top plate, the whole coal pillar loses the stress transmission capability, pressure relief is further realized, and the coal mining face is guaranteed to bemined under a low-stress state. The pressure relief method for the short-distance overlying residual coal pillar has the advantages of scientific principle, reasonable design, strong pertinence, convenient operation, high efficiency, high safety and reliability and good pressure relief effect by adopting the operation mode of combining theory with practice.

Description

technical field [0001] The invention belongs to the field of coal mine safety mining, and in particular relates to a pressure relief method for short-distance overlying residual coal pillars. Background technique [0002] During the mining of coal resources in mines, when the number of coal seams is more than two, descending mining is adopted, that is, the upper coal seam is mined first, and then the lower coal seam is mined sequentially. In the mining of the upper coal seam, coal pillars for various purposes must be reserved due to the need for safe production. After the overlying coal seam is mined, these coal pillars are distributed in different positions in the goaf, and the undamaged coal pillars form stress under the pressure of the roof. Concentrated, it will be effectively transmitted to the floor. If the distance from the adjacent underlying coal seam is less than 20m, it is a close-distance coal seam. When the underlying coal seam is mined, the concentrated stress ...

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Problems solved by technology

However, this method is suitable for coal pillars with an aspect ratio of less than 1. When the aspect ratio is large, the pressure relief effect is very small.

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