Three-soft coal seam gob-side roadway support method

Abstract

The invention relates to a three-soft coal seam gob-side roadway support method which includes the steps: (1) laying metal meshes on two sides and a top plate of a roadway, arranging a steel strip, enabling an anchoring and grouting anchor rod with the length of 2.5-4m to penetrate the steel strip and to be anchored in a surrounding rock, pitching up anchor rods close to the top plate on the two sides by 10-20 degrees, dipping anchor rods at corners by the angle of 15-45 degrees, and enabling the rest anchor rods to be perpendicular to a rock surface; (2) anchoring one end of each anchor rod extending into the surrounding rock by resin after roadway excavation, pre-tightening the anchor rods by pre-tightening force not smaller than 30KN; (3) grouting the pre-tightened anchor rods, turningoff a grouting pump when the pressure of the grouting pump reaches 7Mpa, and performing grouting after 2-3 minutes; (4) performing secondary reinforcement by a hollow anchoring and grouting anchor rope when deformation of the two sides of the roadway exceeds 300mm, enabling the anchor rope to penetrate the steel strip and to be anchored in the surrounding rock, anchoring one end of the anchor ropeextending into the surrounding rock by resin, pre-tightening the anchor rope and then grouting the inside of the anchor rope.

Description

technical field [0001] The invention relates to the technical field of roadway support in coal mines, in particular to a support method for gob-side roadways in three soft coal seams. Background technique [0002] In the process of coal resource mining, in order to improve the recovery rate of coal resources and reduce the stress concentration of multi-coal seam mining, gob-side entry with small coal pillars is used more and more. The width of coal pillars in gob-side roading is generally 5-8m, which can prevent water accumulation in old gobs and harmful gas from entering the roadway. Due to the small width of the coal pillar along the goaf, the surrounding rock mass of the roadway is affected by the mining dynamic pressure of the adjacent working face, and the cracks in the surrounding rock mass are developed, the overall damage is serious, and the strength is reduced. The soft rock itself has low strength, and it is easy to undergo plastic rheology under the action of min...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the deficiencies of the prior art, the present invention provides a gob-side roadway support method for three soft coal seams, which uses super-long, high-strength anchor bolts to reinforce the two sides, uses steel belts to increase the strength of the surface protection, and anchors the anchor bolts under construction. , Secondary reinforcement and reinforcement of the roadway side and other measures, focusing on supporting the two sides of the gob-side roadway and controlling the deformation of the floor, improving the stability of the coal pillar and the supporting capacity of the two sides to the roof, thereby reducing the deformation of the gob-side roadway and successfully solving the problem Difficulties in supporting gob-side roadway in complex soft rock

Images