Method for controlling stability of surrounding rock in gob-side entrydriving of working face of deep island

Abstract

The invention discloses a method for controlling surrounding rock in gob-side entrydriving of a working face of a deep island. The method comprises the following steps of performing pre-cracking and top breaking before stoping of two adjacent working surfaces of the working face of the island, so as to avoid forming a hinge structure at the end surface of the working face, and avoid the hinged rock beam at the critical layer transferring the stoping stress of covering rock of the adjacent working faces to the working face; selecting a constant-drag large-deformation anchor bolt in a gob-side entrydriving support system, increasing the lengths of anchor bolts at the coal wall side and top plate side, deforming the anchor bolts to relieve pressure, and enabling anchor cables to transfer the concentrated stress of the surrounding rock to the farther physical coal wall; slantwise and downwards drilling pressure relief holes in the physical coal wall side with 3 to 4 cycle roof weighting paces in advance at the working face of the island; spraying slurry to the narrow coal column side. The method has the advantages that the stress concentration degree of the deep working face is effectively reduced, the drags of a bracket, a support column and support are reduced, the stoping efficiency of coal sources is improved, the safe and efficient stoping efficiency of the working face is also improved, and the major technical and economic benefits are realized.

Description

technical field [0001] The invention relates to the field of surrounding rock of gob-side entry in a deep island working face, in particular to a stability control method for surrounding rock of gob-side entry in a deep island working face. Background technique [0002] Underground mining occupies an important proportion in my country's coal mines. When the working face is arranged in single-wing strips, in order to facilitate mining replacement and avoid centralized production, skip mining is generally used, thus forming many island working faces. Due to the greater stress concentration of the island working face compared with the ordinary working face, the support resistance of the working face is large and the roadway support is difficult. The width of the coal pillar in the traditional section is 30-50m, and the surrounding rock deformation of the roadway is large during the mining process, which directly endangers the safe and efficient mining of the working face. At p...

AI Technical Summary

Problems solved by technology

However, with the depletion of shallow coal resources, deep resources are being exploited at home and abroad one after another. When mine mining reaches a certain depth, problems such as trussing often occur in the working face, and the surrounding rock of the roadway shows high ground stress and large deformation (severe bottom sag) etc.), zonal cracking, rock burst, coal and gas outburst and other nonlinear physical phenomena, it is difficult to effectively control the surrounding rock of the roadway even if the gob-side driving technology is adopted, which seriously hinders the safe and efficient mining of the working face

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