Research on application of asymmetric supporting technology of gob-side entry driving of narrow coal pillar in deep well

When the -1 000 m horizontal gob-side entry of Shaanxi Gaojiapu Coal Mine was under the original support scheme, the roof and two sides were seriously deformed, part of the rockbolts were pulled off, and the deformation of the two sides was asymmetrical. The deformation of the roadway side of coal pillar was obviously greater than that of the solid coal side, which leads to the roadway can not meet the production demand. This paper analyzed the main problems existing in the original support scheme and put forward the asymmetric support scheme of "high pre-stressed rockbolt + pressure bird’s nest anchor cable + W steel strip". FLAC^3D software was used to carry out numerical simulation of the gob-side entry in deep well after adopting asymmetric support scheme. The results show that the roof subsidence of the roadway is stable at 80 mm, and the displacement of the two sides of the roadway is stable at 179 mm, and the displacement of the two sides of the surrounding rock is roughly similar. There is no obvious asymmetrical deformation phenomenon. The field application and monitoring results show that after the asymmetric supporting technology is adopted for gob-side entry of narrow coal pillars under the influence of high ground pressure in deep well, the deformation of roadway is effectively controlled, and better control effect of roadway surrounding rock is achieved.