Determining the Permissible Longwall Face Advance in the Protective Pillar Conditioning the Liquidation of a Mining Shaft

The presented research subject involved the assessment of the possibility of mining operations within the area of shaft protection pillar with simultaneous liquidation of the shaft. In such a situation, the basic condition is to avoid damage to shaft lining, which can hinder or even prevent safe liquidation of the shaft by backfilling. The procedure to follow in order to assess the possibility and scope of mining exploitation within the shaft protection pillar is demonstrated on the example of shaft X. The applied assessment method involving the possibility and scope of mining exploitation within the protective pillar of the shaft was based on the forecast of rock mass deformation at the shaft site, which was the basis to calculate vertical stresses in the shaft lining and then to compare them with permissible values. The carried out calculations allowed us to determine the permissible face advance of longwall No. 5 at which no damage to the lining and its equipment would occur, ensuring the planned safe liquidation of the shaft by backfilling.