Opposite safe mining method for adjacent working faces under shallow-buried short-distance room-and-pillar goaf

Abstract

The invention discloses an opposite safe mining method for adjacent working faces under a shallow-buried short-distance room-and-pillar goaf. The method comprises the following steps of S1, obtaining the coal pillar stability of the top room-and-pillar goaf based on FLAC3D numerical calculation; S2, on the basis of the coal pillar stability of the top room-and-pillar goaf, carrying out simultaneous mining and single-working-face mining on the adjacent working faces under the room-and-pillar goaf according to different opposite distances, and obtaining the lateral bearing pressure superposition effect and the inter-face coal pillar stability; and S3, on the basis of the coal pillar stability of the top room-and-pillar goaf, the lateral bearing pressure superposition effect and the inter-face coal pillar stability, obtaining opposite mining time sequence plan and method of the adjacent working faces. According to the invention, the safe adjacent working face opposite mining time sequence plan can be formulated, and the safe and reliable adjacent working face opposite mining method is provided.

Description

technical field [0001] The invention relates to the technical field of coal mining, in particular to a safe mining method for adjacent working faces facing each other in a shallow buried short-distance room-pillar goaf. Background technique [0002] Most of the coal seams in Jurassic coalfields in northern Shaanxi occur in the shallow part within 300m, and the top coal seam is generally about 100m away from the surface, which is called a shallow buried coal seam. Thick coal seams are mainly thick coal seams, which belong to shallow buried and close-distance coal seam groups. In the early 1990s, some mines adopted the room-and-pillar method of mining the top coal seam, forming a large number of room-and-pillar goafs. Later, the wall mining method was gradually promoted, forming a large number of The wall-type goaf brings potential safety hazards to the mining of the lower coal seam. At present, the top coal seams of most mines in this coalfield have basically been mined, and...

AI Technical Summary

Problems solved by technology

[0002] Most of the coal seams in Jurassic coalfields in northern Shaanxi occur in the shallow part within 300m, and the top coal seam is generally about 100m away from the surface, which is called a shallow buried coal seam. Thick coal seams are mainly thick coal seams, which belong to shallow buried and close-distance coal seam groups. In the early 1990s, some mines adopted the room-and-pillar method of mining the top coal seam, forming a large number of room-and-pillar goafs. Later, the wall mining method was gradually promoted, forming a large number of Wall-type goaf, which brings potential safety hazards to the mining of lower coal seams

At present, the top coal seams of most mines in this coalfield have basically been mined, and the lower coal seam mining has gradually begun, which belongs to "mining under the gobs of shallow buried and close-distance coal seam groups". The structure of the remaining coal pillars and interval rock strata is greatly affected, especially when mining under the room-and-pillar goaf, it is easy to cause large-scale collapse of the room-and-pillar goaf, resulting in strong mine pressure disasters and toxic and harmful gas exceeding the limit. Common technical problems faced by mining under the close-distance room-and-pillar goaf; at the same time, due to mining history, some adjacent mines are mining the lower coal seam under the room-and-pillar goaf. Independent, facing the special technical problems of facing each other in the adjacent working faces of adjacent mines

[0003] During the opposite mining process of the adjacent working faces of adjacent mines, the leading bearing pressure of the two working faces may be superimposed, and the lateral bearing pressure of the working face has a stronger influence on the coal pillar between the faces than the mining of a single coal seam, which can easily lead to the upward pressure of the two working faces during the mining process. Sudden collapse of the room-and-pillar goaf, instability of coal pillars between faces, and other disasters have caused safety accidents such as crushing of supports on the two working faces of the lower coal seam, and harmful gas influx into the working face of the room-and-pillar goaf. It is very necessary to ensure the safe mining of the two working faces facing each other in the timing planning of the adjacent working faces of adjacent mines buried in close-distance room-and-pillar goafs

[0004] In addition, the existing technology has conducted a lot of research on the stability of coal pillars in mining backing roadways under single working faces in shallow buried and short-distance gobs, and the distribution of advanced bearing pressure on single working faces, and has achieved many beneficial results, but it does not involve adjacent working faces. The stability analysis of coal pillars between faces in the mining process, the prediction of the stability of the upper room-and-pillar goaf, and the superposition effect of the support pressure of the surrounding rock in the mining of the two working faces facing each other are still in the leading position in the safe mining technology of adjacent working faces. blank

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