An anchoring structure and reinforcement method for narrow coal pillars in gob-side entry retaining

Abstract

The invention relates to an anchoring structure and reinforcing method of a narrow coal pillar of gob-side entry retaining. The anchoring structure comprises obliquely-pulling anchoring systems and gob-side entry retaining opposite-position anchoring systems, which are arranged in the length direction of the narrow coal pillar at intervals, and horizontal side-limiting reinforcing devices are used for further fastening the obliquely-pulling anchoring systems. The reinforcing method comprises the following steps of firstly drilling horizontal drill holes and top and bottom plate inclined drill holes in the narrow coal pillar in an upper-segment mining roadway, mounting the obliquely-pulling anchoring systems and the gob-side entry retaining opposite-position anchoring systems including grout leakage preventing bags, horizontal and inclined grouting anchor rods and the like in respective drill holes, mounting the horizontal side-limiting reinforcing systems at positions corresponding to the obliquely-pulling anchoring systems on two sides of the narrow coal pillar, then applying prestressing force to nuts on each system, and finally performing grouting on the anchor rods through a grouting machine. According to the anchoring structure disclosed by the invention, the safety and the stability of the narrow coal pillar gob-side entry retaining are effectively guaranteed, roadway deformation is effectively reduced, the plastic zone of the coal pillar is reduced, the repair cost of the roadway can be reduced, the structural design is reasonable and simple, the construction is convenient, the reinforcing effect is obvious, and the coal recovery ratio is increased.

Description

technical field [0001] The invention relates to an anchoring structure and a reinforcement method of a narrow coal pillar in gob-side entry retention, and belongs to the field of coal mine support. Background technique [0002] Gob entry retention has significant technical advantages and economic benefits. It is divided into wide coal pillar gob entry retention, narrow coal pillar gob entry retention and no coal pillar gob entry retention. Coal pillars are used to replace artificially constructed "separation "Wall", not only saves the cost of artificial wall pumping concrete, but also reduces the man-hours and material costs of concrete pipeline laying, and avoids the transportation of concrete and other materials. With the gradual depletion of shallow coal mine resources in my country, most mines have been transferred to deep coal seam mining, and some problems will arise, such as severe mine pressure, poor roadway stability, difficult roadway maintenance, and high repair r...

AI Technical Summary

Problems solved by technology

With the gradual depletion of shallow coal mine resources in my country, most mines have been transferred to deep coal seam mining, and some problems will arise, such as severe mine pressure, poor roadway stability, difficult roadway maintenance, and high repair rate. To solve it scientifically and rationally at the cost of leaving wide coal pillars blindly will inevitably lead to waste of coal resources, low recovery rate of coal resources, large amount of roadway excavation, high labor intensity of workers, tension in mining continuity, and stress on coal pillars in sections. Therefore, the narrow coal pillar gobside retaining technology has more obvious economic advantages compared with the wide coal pillar. However, the current method of coal pillar support mainly adopts section coal pillar coal wall side bolt support. Applying it to the support of narrow coal pillars will cause problems such as small elastic core area in the center of the coal pillar, large plastic area, serious roadway side, obvious bottom heave, poor safety and stability, etc., and it is not conducive to the later maintenance of gob-side entry retaining , often require rework

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