Research and application of roof strip weakening technology in isolated island working face

In order to solve the problem of rock pressure appearance in 3203 isolated island working face of Wangpo Coal Mine, based on the mechanical mechanism of roadway deformation, the roof strip weakening model was established and applied in the headentry. The deformation of roadway surrounding rock, the stress of section coal pillar, the support working resistance and microseismic events were compared and analyzed with the unused return airway. The test results show that, during the coal winning of the working face, compared with the return airway, the roof subsidence, the floor heave and the displacement of the two sides is reduced by 26.75%, 36.19% and 27.63% in the headentry adopting the roof weakening technology. The stress of the coal pillar at the side of the headentry increases with the increase of the distance from the coal pillar, which is only 58.00% of the stress at the return air side. The peak working resistance of the support at the side of the headentry is 13.30% lower than that at the return air side. The high energy events in the headentry are reduced, and the low energy events are significantly increased. 62.00% of the microseismic events in return airway are concentrated at 0 m to 20 m above the roof. 68.00% of the microseismic events in the headentry are concentrated in the upper rock layer of the roof (>20 m).The research results can provide theoretical reference for safe and efficient mining of isolated island working face.