Method for supporting laneway below coal pillar

Abstract

The invention discloses a method for supporting a laneway below a coal pillar. The method comprises the following steps of: firstly, arranging temporary supports on a top plate and two sides of the laneway, paving a metal mesh and a steel band, pressing the metal mesh with the steel band and supporting the steel band with a monomer hydraulic support post; secondly, drilling holes on the top plate through the orifice of the steel band of the top plate by using drill bits matched with the diameters of threaded steel anchor rods in combination with a drilling machine, arranging the threaded steel anchor rods into drilling holes in sequence and reaching pre-tightening force by using a nut; and lastly, drilling holes on laneway sides from the orifices of the steel bands on the laneway sides by using drill bits matched with the diameters of threaded steel anchor rods in combination with the drilling machine, arranging hydraulic expansion anchor rods into the drilling holes on the laneway sides in sequence, and injecting high-pressure water into the hydraulic expansion anchor rods to expand the hydraulic expansion anchor rods. Anchor ropes are arranged on the top plate and the two sides at specific intervals during the performance of the procedures. The procedures are repeated until the laneway below the coal pillar is supported. The hydraulic expansion anchor rods adopted in the method can realize full-length anchorage; and after the anchor ropes are used for reinforcing and supporting the laneway, the surrounding rock deformation of the laneway below the coal pillar can be effectively controlled.

Description

technical field [0001] The invention relates to a roadway support method under a coal pillar, which is especially suitable for the support of the roadway under the coal pillar at the beginning of a coal seam group at a very short distance, and can also be applied to the support of the roadway with high stress and broken surrounding rock. Background technique [0002] For coal seam group mining, when the distance between coal seams is large, the mining of the upper coal seam has little impact on the mining of the lower coal seam. However, as the distance between coal seams decreases, the mutual influence of mining between the upper and lower coal seams will gradually increase, especially when the distance between coal seams is very close (less than 1.5m), the integrity of the roof before the mining of the lower coal seam has been damaged by the mining of the upper coal seam In addition, the concentrated pressure formed by the residual section coal pillars on the floor after t...

AI Technical Summary

Problems solved by technology

However, as the distance between coal seams decreases, the mutual influence of mining between the upper and lower coal seams will gradually increase, especially when the distance between coal seams is very close (less than 1.5m), the integrity of the roof before the mining of the lower coal seam has been damaged by the mining of the upper coal seam and the concentrated pressure formed by the remaining section coal pillars on the floor after the mining of the upper coal seam leads to changes in the roof structure and stress environment of the mining area of ​​the lower coal seam

As a result, when the lower coal seam is mined, the mine pressure of the mining roadway is very obvious, the surrounding rock of the roadway is moved closer, and the roadway support is difficult

At present, high-strength threaded steel bolts are usually used for support in this situation. If the deformation of the surrounding rock cannot be effectively controlled, the support density can be increased, or the support should be supported first, but the effect is not obvious.

Especially for the support of the two sides, due to the downward transmission of the concentrated load of the coal pillar, a high-stress environment is formed, which makes the surrounding rocks of the two sides more broken, and the use of resin anchors is prone to failure