Research on deformation and failure characteristics of coal roadway in sedimentary variation area and control technology of thick layer anchor grouting

In view of the problems of high stress concentration and serious deformation and failure of roadway surrounding rock in sedimentary variation area.Taking the haulage gateway of 7303 working face in Zhaolou Coal Mine as the engineering background, based on the on-site investigation, three types of deformation and failure modes of roadway surrounding rock in sedimentary variation area are summarized, and the characteristics of mine pressure during tunneling of intact rock stratum and sedimentary variation roadway are simulated and compared.In abnormal roadways, the local stress concentration degree of surrounding rock is high, and delamination is easy to form at the interface of rock strata, resulting in zonal damage, and the plastic zone is obviously increased.Furthermore, the control technology of thick layer anchor grouting is put forward, and the organic combination of thick layer anchor grouting modification is realized by using flexible grouting anchor.Finally, the repair and reinforcement scheme is designed and the industrial test is carried out.The results show that the resistance of bolt-cable support is stable, the deformation speed of roadway surrounding rock slows down, the deformation is controlled within 100 mm, and the crack develops in the foundation anchorage layer, with good control effect.