Movement and deformation characteristics of overlying rock mass in deep coal seam

The 110 mining method is an innovative and useful coal mining technology. It mainly relies on two technologies to improve coal mining rate: Top cutting and pressure relief, Negative Poisson's ratio anchor cable (NPR anchor cable) support. This study develops a large-scale physical model test using the speckle monitoring system (DIC), the stress-strain monitoring system, and the infrared thermal imaging system to deeply investigate the roadway deformation and failure law of the 110 mining method, the displacement movement mechanism of the overlying rock mass, and the change law of rock pressure. Results showed that pillarless coal mining utilizing mine pressure and rock fragmentation and expansion characteristics, the use of cut top pressure relief and NPR anchor stress compensation technology in the kilometer level of deep underground coal mining still has a positive effect along the tunnel space. In addition, they can reduce surface subsidence, provide a scientific basis for ecological protection, and develop other kilometer-level deep soft rock high-ground stress underground projects.