Study of the dynamics of delamination development in the roof of mining workings of large cross-section

Abstract In the work, based on the results of long-term observations of the dynamics of delamination of roof rocks, the criteria for determining the category of stability of mining workings of a large cross-section are substantiated. World experience is analyzed and a proprietary control method is presented, which was implemented at a gypsum mine in chambers up to 18 m high. The method includes vibroacoustic diagnostics to detect delaminations, control drilling, and long-term control of roof deformations visually and with the help of special observation stations. The negative impact of temperature changes on the stability of the roof and the operation of observation stations was established. The impact of freight transport is not significant. Beyond geological disturbances, deformation processes in the roof are slow and predictable. Three options for the development of the geomechanical situation were identified: long-term stabilization, uniform projected lowering of the roof, and a rapid increase in the rate of deformation with collapse. The criteria for determining the category of roof stability, which take into account the area of peeling, the rate of growth of vertical deformation and the intensity of the formation of cracks, are substantiated.