Evaluation of geomechanical conditions at Magnezitovaya mine when undermining natural and anthropogenic objects

Development of Satka magnesite deposit is carried out in complicated geomechanical conditions, in particular, mining works are conducted under the Bolshaya Satka river, in the zone of influence of the existing and developed quarries. Underground workings undermine a number of surface objects of industrial and civil purpose: railways, bridges, buildings and structures. There was an urgent need to conduct special studies of geomechanical conditions at the mine in order to assess the feasibility of working off part of the safety pillars located under the railway tracks of "Russian Railways", PJSC and the river bed. In the process of research, the main physical and mechanical properties of rocks have been identified, and the initial natural stresses of the rock mass have been measured. An increased level of horizontal initial stresses in the zone of safety pillars at the horizons + 180. + 260 m was detected. Based on the results of the research, a conclusion was made on the need to develop some engineering measures to ensure the safety of underground works. It was recommended, to ensure the stability of the rocks massif, to apply the option of extracting the treatment chambers with the formation of the ceiling of the vaulted form. It is proposed to monitor deformation processes in mine workings and on the daylight surface. To this end, the installation of an automated control system for rock pressure is recommended. It is necessary to provide for the establishment of long-term observation stations for controlling rock pressure and displacement. According to the results of the research, "Guidelines for the safe control of mining operations at bump-hazardous Satka magnesite deposit" have been developed in accordance with the requirements of the Federal norms and regulations in industrial safety