A pressure relief method for overlying residual coal pillars at short distances

A short-distance, coal-pillar technology, applied in earthwork drilling, surface mining, underground mining, etc., can solve problems such as weak pressure relief effect

Active Publication Date: 2020-10-13
山西工程技术学院
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  • Description
  • Claims
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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.

Method used

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  • A pressure relief method for overlying residual coal pillars at short distances
  • A pressure relief method for overlying residual coal pillars at short distances
  • A pressure relief method for overlying residual coal pillars at short distances

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specific example

[0053] The width of the residual coal pillar in the No. 2.3 coal seam in a coal mine is 16m, the height is 4.57m, the thickness of the underlying No. 4 coal seam is 3.05m, and the distance between the No. 2.3 coal seam and the No. 4 coal seam is 10m. The distance to the left side of the underlying coal seam is 10m.

[0054] (1) Sampling by drilling, collecting 5 coal samples from the overlying coal seam on site;

[0055] (2) Process the coal samples obtained in step (1) into 6 standard test pieces in the laboratory, conduct variable-angle shear experiments, and measure the cohesion of the coal samples , coal seam internal friction angle ;

[0056] (3) The coal sample cohesion C and internal friction angle measured according to step (2) , to determine the width X of the crushed zone 6 formed by the impact of primary mining in the coal pillar 1 :

[0057]

[0058] Where: the height of the overlying coal pillar M =4.57m; Coal seam Poisson's ratio , side pressure coe...

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Abstract

A method for pressure relief of residual coal pillars at a short distance, comprising the steps of: making a standard test piece in a laboratory after sampling, and determining the width X of the crushed zone formed by the impact of primary mining in the coal pillars 1 and the width of the broken zone formed by the impact of secondary mining on the coal pillar X 2 : At the site, holes are drilled upwards on the side of the roadway near the coal pillar in the underlying coal seam, and explosives are filled in the borehole for blasting. Further damage under load will cause the entire coal pillar to lose its stress transmission capacity, thereby achieving pressure relief and ensuring coal mining face mining under low stress conditions. The invention has a scientific principle, a reasonable design, adopts an operation mode combining theory with practice, and has the advantages of strong pertinence, convenient operation, high efficiency, strong safety and reliability, and good pressure relief effect.

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 ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): E21C41/18F42D3/00
CPCE21C41/18F42D3/00
Inventor 郑文贤王凯李全中张海东
Owner 山西工程技术学院
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