Application of Pipe Slit Anchor Mesh Spraying Supporting Technology Based on Loose Circle Supporting Theory in Makeng Iron Ore Mine

In order to solve the problems of stress concentration in the roadway peripheral rock and poor support effect in a wide range of high-stress areas under the high-stress environment of MaKeng Iron Mine, this study is based on the theory of loose circle support, combined with the calculation of the anchor suspension theory to determine the reasonable length of pipe slit anchors and other key parameters. Through the two methods of punching and bonding, we examined the destructive effect to determine the thickness of the spray concrete and, finally, put forward the pipe slit anchor mesh spraying support technology program. The numerical model was constructed by using three-dimensional numerical simulation software (FLAC3D 5.0), and the support effect analysis of the support scheme was carried out systematically. The research results show the following: under the high-stress environment dominated by external horizontal tectonic stress, the use of pipe slit anchor net spray support technology can significantly improve the distribution characteristics of the plastic zone, stress field and displacement around the roadway; after the support, the deformation and displacement of the surrounding rock around the empty zone are significantly reduced, effectively preventing the destruction of the surrounding rock under the high-stress environment. The program not only unifies the mine support form and support parameters but also specifies the support construction method and construction quality inspection standard, which provides a scientific technical guarantee for mine shaft support and has an important reference value for the support design and construction of a mine roadway under a similar high-stress environment.