Study on surrounding rock support technology of deep soft rock roadway

In order to effectively solve the problem of surrounding rock control in deep soft rock roadways, in view of the characteristics of large burial depth, high stress and low surrounding rock strength of the air returning cross-cut of Xinhu Coal Mine, the surrounding rock occurrence conditions and factors of the return air crosscut in Xinhu coal mine were analyzed. Under the condition that the deformation and failure characteristics and the original support scheme have been difficult to maintain the stability of the existing roadway, the plastic zone of the surrounding rock of Xinhu coal mine was obtained by theoretical calculation, and the basic concept of controlling the surrounding rock of the roadway was put forward: the bearing body controls the expansion of the surrounding rock fracture zone, and the large bearing body was used to limit the development of the plastic zone of the surrounding rock. The two bearing structures jointly maintain the stability of the roadway, and then the joint support scheme of “anchor cable” supports the newly excavated roadway, and combined with Flac3D numerical simulation and on-site industrial experiments, the joint support scheme of “concrete spray + grouting bolt/anchor cable + ordinary bolt/anchor cable” was supported, and reasonableness and reliability were verified. The results show that the deformation of the surrounding rock surface tends to be stable after the support of the concrete support + grouting anchor / anchor cable + ordinary anchor / anchor cable in the new roadway section of the air returning cross-cut of Xinhucoal mine, the roof of the roadway. The maximum subsidence amount is only 36 mm, and the moving distance of the two groups is 67 mm. The supporting body and the surrounding rock of the roadway form a stable composite bearing structure. The joint support scheme can maintain the long-term stability of the roadway, and the joint support scheme can provide a certain reference for the support of other similar deep soft rock roadways.