Integral high-strength flexible support method of roadway at large-inclined angle coal-seam longwall mining section

Abstract

The invention discloses an integral high-strength flexible support method of a roadway at a large-inclined angle coal-seam longwall mining section. The method comprises the following steps: 1. mining a first coal-mining section / working face; 2. supporting and mining a second coal-mining section / working face: opening up a return-air driftway and a haulage driftway, supporting the return-air driftway by a flexible roadway support system, stoping the second coal-mining section / working face and weakening the supporting action of protective coal pillars at the section on a roof, and carrying out top coal caving mining so that the two coal-mining sections / working faces form an integral working face; 3. supporting and mining next coal-mining section / working face; 4. repeatedly supporting and mining until all the coal-mining sections / working faces are completely supported and mined at the same stage; and 5. mining for next stage and rearranging the flexible roadway support system. The flexible support method has the advantages of reasonable design and low cost, and the flexible roadway support system has a good application effect, thus solving the instability problem of a 'roof-support-floor' system in an upper area of the working face during the large-inclined angle coal-seam mining process.

Description

technical field [0001] The invention relates to a roadway support method in the process of coal seam mining, in particular to an overall high-strength flexible support method for a roadway in a long-wall mining section of a coal seam with a large dip angle. Background technique [0002] The high dip angle coal seam is a part of the medium and steep coal seams, and its general dip angle α is 35°-55°. The high dip angle coal seam is recognized as a difficult coal seam by the international mining community. [0003] When the high-dip-angle coal seam is mined toward the longwall working face (ie, the longwall mining section), the rock fracture, movement and mine pressure manifestation along the length of the working face can be divided into three areas: roof activity (or mine pressure manifestation) is relatively Weak lower region, middle region where roof activity (or mine pressure manifestation) is limited to a certain extent, and upper region where roof activity (or mine pres...

AI Technical Summary

Problems solved by technology

[0004] After analysis, it is concluded that the stability of the support (or support system) in the longwall working face of a large-inclination coal seam depends on the contact state between the support (or support system) and the roof and floor. In the upper area of ​​the working face, the roof caving The gangue slides down (or rolls) to make the contact between the support of the working face and the top and bottom slabs present a random and irregular state (especially in caving coal mining). Section protection coal pillars and roadway support constitute a relatively complete support system, forming a mechanical support between this section (that is, the working face that has been mined) and the upper section (that is, the working face that has been mined). area, which cuts off the large-scale movement (movement) kinematics connection of the roof strata between the two sections, and prevents the upper section (that is, the working face that has been mined) from the mining (empty) zone roof downward section (that is, the current The mining working face) is transported (moved) to fill the space in the upper area of ​​the existing mining working face due to the roof caving and the gangue sliding down (rolling), thus making the support (or support) system in the upper area of ​​the working face unstable. Guaranteed, it will inevitably lead to the instability of the support (or support system) in the local area of ​​the working face, and the phenomenon of the support falling, sliding, squeezing and biting will occur, and this phenomenon has a "Domino effect", which will move from the upper area of ​​the working face to the The development of the central region caused the instability of the "roof-support-bottom" system in a large area of ​​the working face, resulting in the shutdown of the working face

What is more serious is that once the "roof-bracket-bottom" system becomes unstable, the breakage and movement of the roof of the working face loses the restraint and control of the bracket, and shock dynamic pressure may appear, causing a catastrophe in the surrounding rock of the working face, resulting in safety hazards. Accidents, but also greatly restricted the increase in production and efficiency of the working face

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