Geomechanics of overworked mine working support resistance in the laminal massif of soft rocks

Abstract

The relevant issues of ensuring trouble-free mining operations on the underlying horizons, which are partially or fully overworked are studied in this paper. The problem has been solved using the example of a laminal massif of the Western Donbas soft rocks; complicating factors were taken into account: water-cut, fracturing, and the rheological properties manifestation. The model, proposed for calculation, has been substantiated in view of geomechanics, as well as the finite element method has been chosen to obtain the stress-strain state of the adjacent massif and support. At the first stage, mine observations of the state of mine working planned for overworking have been conducted and analysed. At the second stage, a computational experiment has been conducted in the most difficult areas. The stresses fields have been analysed according to vertical, horizontal and stresses intensity components of the soft rocks laminal massif, as well as their distribution curves for the recommended and basic fastening options. It has been proved that the recommended parameters of the fastening structure provide repair-free mine working maintenance for the entire exploitation period with account of overworking. Recommendations have been developed for mining the seam C6 in M.I. Stashkova Mine, DTEK Pavlohradvuhillia PJSC.