Surrounding rock control technology of gob-side entry driving in deep shaft with high stress roof cutting and pressure relief

In order to solve the problems of tension of mining and excavation replacement,serious deformation of gob-side entry driving and difficulty of supporting in coal mine,taking Zhaogu No.1 coal mine as engineering background,the technology of advanced pre-splitting roof cutting and pressure relief in gob-side entry driving was proposed.Based on the technical principle of roof cutting and pressure relief along gob,the mechanical environment of surrounding rock of the gob-side entry driving is analyzed theoretically,and the related technical parameters of blasting,charging and support of gob-side entry driving are determined in the advanced pre-splitting and pressure relief technology.The industrial test was carried out on site.The test results show that advanced pre-splitting roof cutting and pressure relief driving technology along the gob can artificially pre-crack the seam,cut off the connection between the roof of gob-side entry and the roof of coal pillar,improve the mechanical environment of gob-side entry driving,and ensure the overall stability of its roof structure.The pre-splitting blasting roof cutting and pressure relief technology has a good pressure relief effect on the adjacent working face along the gob.The relative displacement of roof and floor of the gob-side entry is 60～180 mm,the relative displacement of the two sides is 25～80 mm,and the maximum load pressure of anchor cable is 24 MPa.During the driving period,the pressure of surrounding rock of the gob-side entry decreases,which effectively suppresses the gob-side entry deformation and significantly improves the support quality.The application of gob driving technology in Zhaogu No.1 Coal Mine has effectively solved problems such as the shortage of mining replacement.