Aiming at the surrounding rock control problems of gob-side entry retaining under the condition of deep water-rich composite roof, the support design and stress analysis were carried out. By analyzing the influence mechanism of composite roof structure and water-rich environment on surrounding rock stability, the limitations of traditional support methods in controlling continuous deformation and floor softening were pointed out. The collaborative control technology system was proposed as follows. Firstly, the constant resistance anchor cable with a length of 11.8 m was used for three rows of vertical roof support, and the two-way shaped charge blasting roof cutting technology was combined to block the lateral stress transmission in the goaf. Secondly, "one beam and four columns" hydraulic support was set up in the dynamic pressure area to strengthen the support. Thirdly, in the drenching section, C20 concrete bedding and grouting anchor cable joint technology were used to control the water seepage softening of the bottom plate. The engineering application results show that the proposed control system reduces the time from severe deformation to stability by more than 40%, the maximum cumulative convergence of the left side of the return air chute is controlled within 940 mm, and the floor heave is significantly reduced within 660 mm. The proposed collaborative control technology can effectively deal with the complex geological conditions of water-rich composite roof, and realize the long-term stability control of gob-side entry retaining. The research results can provide a reliable technical basis for non-pillar coal mining under deep and complex geological conditions.

Water-rich composite roof  /  Deep mining  /  Surrounding rock stability  /  Non-pillar coal mining  /  Roof cutting and entry retaining  /  Collaborative control technology