Extra-thick coal seam top coal caving working face roadway arrangement method

Abstract

The invention discloses an extra-thick coal seam top coal caving working face roadway arrangement method which comprises the steps that after two roadways and open-off cuts of a working face are tunneled along a coal seam bottom plate, a last mining top-following preparation roadway is tunneled along a coal seam top plate and the trend of the working face; tunneling an end mining top-along operation roadway parallel to the open-off cut every one cycle in a weighting step pitch along the end mining preparation roadway, performing loose blasting on a top plate of an end mining section working face before the advanced bearing pressure of the working face affects the end mining section working face, and then performing top-cutting presplitting blasting on a working face mining roadway, and the top plate of the end mining section is subjected to sufficient anti-reflection crushing. When the working face is pushed to the end mining section, a goaf top plate is fully caved, the gangue filling degree is good, and the overlying rock supporting capacity is greatly improved compared with a natural caving method, so that the stope advance bearing pressure distribution condition is optimized, the working face advance bearing pressure appearance strength is reduced, the size of an end mining coal column is reduced, and the retracement roadway stress environment is optimized; and part of coal resources in the tail coal mining column are recycled.

Description

technical field [0001] The invention relates to a coal mining technology, in particular to a roadway layout method for a top-coal caving face in an extra-thick coal seam, and is especially related to maintenance of a main road during the final mining period and reduction of the final mining coal pillar. Background technique [0002] With the increase of the coal seam height, the impact of mining on the working face, especially the top coal caving face, is gradually increasing, which is manifested in the collapse of the roof of the coal wall, the severe deformation of the mining roadway in the advanced working face section, and the remaining protective coal at the end of mining. The large column size not only increases the roadway support and maintenance costs during mining, but also makes a large amount of coal resources remain underground and cannot be mined. [0003] After the working face is mined, the overlying roof collapses downward, destroying the initial equilibrium ...

AI Technical Summary

Problems solved by technology

Goaf filling currently has problems such as high cost and affecting the advancing speed of the working face. It is often only used in the mining of "three lower" coal seams; loose blasting is often used during the initial mining of thick and hard roofs to prevent the roof from hanging over a long distance The pressure brought about is released in a concentrated manner, but it cannot continue with the advancement of the working face; the pre-splitting top cutting blasting technology is used in the roof of the mining roadway near the goaf side, which can relieve the pressure on the roadway roof. Improve the stress distribution of the roadway surrounding rock, but it is difficult to affect the collapse and stress distribution of the entire stope roof

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