Surface deformation abnormal characteristics of ultra-thick and weakly consolidated overburden and its disaster control method

The surface subsidence under ultra-thick weakly cemented overburden exhibits the abnormal characteristics of being seriously small, which brings serious safety hazard to the efficient mining. A comprehensive analysis of the causes behind the abnormal surface deformation characteristics under ultra-thick weakly cemented overburden was undertaken through theoretical analysis and numerical simulation. The results indicated that when the mining degree exceeded the critical value (900 m), the fracture of the super-thick and weakly consolidated overburden occurred. At this point, the energy was rapidly dissipated, and the surface subsidence suddenly increased. Against this backdrop, a novel regional strata movement control method for the high-intensity and safe mining of super-thick and weakly consolidated overburden is proposed. It could provide technical support for the high-intensity and safe mining of the super-thick and weakly consolidated overburden.