A gob-side digging method for piers without blasting and top cutting

Abstract

The invention discloses a gob-side excavation method for pier columns without blasting, the method comprising the steps of: arranging a plurality of slit holes, the plurality of slit holes together form a pre-splitting slit, and drilling the slit holes ahead of the working surface by 60 ~100m; Excavate the coal pillar side at intervals of 5-10m to arrange concrete pier molds on the side of the coal pillar in the trough near the next working face; use single hydraulic props and Π-shaped steel as temporary supports in the trough Anchor construction in the trough close to the next working face; recovery of single hydraulic props at 2‑5m behind the working face; along the roof of the gob-side excavation roadway, the pre-split kerf collapses along the kerf hole, Eliminate the suspended roof, fill the goaf, and carry out roadway construction along the gob after the adjacent goaf is mined at intervals of 3-5m coal pillars. The invention adopts pier pillars without blasting to cut the top and relieve pressure, and the adjacent working face can carry out small coal pillar gob-side digging operations, which greatly relieves the tense situation of mine excavation and replacement, reduces the cost of reverse repair of gob-side digging roadways, and improves the coal recovery rate .

Description

technical field [0001] The invention relates to a gob-side digging method for pier pillars without blasting and top-cutting, and belongs to the technical field of shallow geothermal energy. Background technique [0002] The traditional gob-side entry generally starts construction more than 10 months after the mining of the adjacent working face. The coal pillars are small, and the roadway of gob-side entry is in the stable zone of rear bearing pressure, so the maintenance of the roadway is relatively easy. Mining of coal seam groups at close distances has high in-situ stress, great influence of mining, and tight excavation succession. Often the adjacent working faces are excavated before the goaf is completely mined, and the sideways hanging area of ​​the goaf next to the coal pillar is prone to appear. large and insufficient caving, the roadway is significantly affected by the movement of the overlying rock in the adjacent goaf, and the mine pressure is severe. Under the in...

AI Technical Summary

Problems solved by technology

[0002] The traditional gob-side entry generally starts construction more than 10 months after the mining of the adjacent working face, the coal pillar is small, the roadway of gob-side entry is in the stable zone of back bearing pressure, and the roadway maintenance is relatively easy

Mining of coal seam groups at close distances has high in-situ stress, great influence of mining, and tight excavation succession. Often the adjacent working faces are excavated before the goaf is completely mined, and the sideways hanging area of ​​the goaf next to the coal pillar is prone to appear. large and insufficient caving, the roadway is significantly affected by the movement of the overlying rock in the adjacent goaf, and the mine pressure is severe. Under the influence of strong mining in this working face, the deformation of the roadway is large and the repairs are frequent, which seriously threatens the safe and efficient mining of the mine

[0003] Adopting heavy-duty U-shaped steel retractable brackets and reinforced control technology for post-filling of the combined frame supported by bolts, the supporting process is complicated and the cost is high

Increase the width of isolated coal pillars, resulting in low coal recovery rate, great waste of resources, and shortened mine service life

Therefore, neither of the above two main methods can satisfy the stability of the low-cost roadway and the normal replacement of the working face in the gob-side roadway under the high-stress and strong-dynamic-pressure soft rock.

Images