Research on collaborative control technology for surrounding rock pressure relief and support of gob-side entry

In order to solve the problem of the support pressure of the cantilever beam formed by the unbroken main roof in the adjacent gob, the hydraulic fracturing roof pressure relief method is adopted to pre-fracture the main roof in the gob and minimize the adjacent mining. The canopy structure is basically formed in the roof of the gob, there by reducing and transferring the strength of the supporting pressure on the roof of the gob-side entry. On this basis, the soft film bag filling concrete is used as a artificial wall in the gob-side entry and gob section, and the underground strength test of the filled concrete is carried out. At the same time, the roof of the gob-side entry and the artificial wall are strongly anchored and supported by the mesh to make it recover to three-dimensional stress state to the maximum extent and improve their load resistance. The comparison between the pressure stress of the artificial wall and the displacement of the roof and floor shows that after hydraulic fracturing and decompression, the maximum compressive stress of of the roof of the roadway is 21 MPa, which is 36.4% lower than the area without hydraulic fracturing and pressure relief; the displacement of the roof and floor in the gob-side entry is 320 mm, which is reduced by 46.5%. After hydraulic fracturing and pressure relief, the stress environment of No.3109 auxiliary air intake roadway has been greatly improved, the displacement of the roof and floor of the gob-side entry has been reduced, the safe use of the gob-side entry has been ensured, and the tension of mining has been effectively relieved.