Gob-side entry driving small coal pillar high-pressure grouting strengthening and supporting method

Abstract

The invention discloses a gob-side entry driving small coal pillar high-pressure grouting strengthening and supporting method. The gob-side entry driving small coal pillar high-pressure grouting strengthening and supporting method comprises the following steps that (1) after a tunnel is subjected to machine driving and shaped, a top plate of the tunnel is subjected to construction of conventionalanchor rods, high-intensity anchor rods and pre-stressed force anchor cables, and corresponding anchor screens are paved for supporting the tunnel; (2) small coal pillars in the tunnel of the step (1)is subjected to construction of a plurality of rows of conventional anchor rods, high-intensity anchor rods and hollow grouting anchor cables in sequence, high-pressure cement concrete slurry is grouted into the hollow grouting anchor cables through a grouting pump, the length of the anchor cables meets the requirements for strengthening width of the small coal pillars, and the conventional anchor rods, the high-intensity anchor rods and the hollow grouting anchor cables are fixed together by a reinforcing bar ladder beam on the contacting wall surface of the small coal pillars and the tunnel; and (3) the multiple rows of the conventional anchor rods are drilled into a solid coal bed of the tunnel in the step (2). The gob-side entry driving small coal pillar high-pressure grouting strengthening and supporting method can perform high-pressure grouting on the gob-side entry driving small coal pillars, the small coal pillars can be strengthened, and the deformation of the tunnel can be reduced.

Description

Technical field [0001] The invention belongs to the reinforcement and support technology for the surrounding rock of a coal mine roadway, and in particular relates to a high-pressure grouting reinforcement and support method for a small coal pillar along a goaf roadway. Background technique [0002] Driving along the goaf, also known as driving along the goaf, can be divided into two types: driving along the goaf completely and driving along the gob with small coal pillars. Roadway digging completely along the goaf means digging the roadway along the boundary of the goaf. At this time, the gas, stagnant water, and large gangue in the goaf may enter the driving roadway and bring safety hazards to coal production. Keeping small coal pillars and driving along the gob is to leave a certain width of small coal pillars between the roadway and the mined area to protect the roadway. The width of the small coal pillars is generally about 5m. Using small coal pillars to drive along the goa...

AI Technical Summary

Problems solved by technology

However, under the action of mining pressure, the small coal pillars will be crushed and damaged at first and then become unstable, which will easily cause the reinforcement failure of the anchor rods and anchor cables. Columns are effectively reinforced

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