Peculiarities of mining the protecting pillar in the laminal massif of soft rocks

Abstract

PeculIArItIeS of MINING the ProtectING PIllAr IN the lAMINAl MASSIf of Soft rocKSPurpose. Increasing the completeness of mining coal reserves from protecting pillars located in a laminal massif of soft rocks in the roof and bottom in order to reduce the coal losses in mines and horizons in case when mining operations are at the stage of completion.Methodology. A geomechanical model is developed for research into mining of protecting pillars influenced by stope works, taking into account the laminal massif and rheological processes of creep deformations and stress relaxation of the rock massif. Numerical modelling and analysis of the stressstrain state of the massif are conducted. Conclusions are drawn in terms of sub stantiation of the technical solutions for mining the protecting pillars.findings. New patterns have been determined of the stressstrain state of a laminal rock massif in the zone influenced by stope works. A geomechanical model has been developed for mining the protecting pillars with account of rheological processes in the rocks, and the technological parameters of mining the coal from longwall faces have been substantiated. A possibility is provided for repeated use of mine workings by introducing a resourcesaving fastening system.originality. The patterns have been determined of the frontal bearing pressure zone displacement ahead of the longwall face during mining the protecting pillars, as well as the concentration factor Ky = 1.1-1.3 at a height from the c 6 coal seam up to 18-20 m, when contacting the thick siltstone. It was found that the calculated compressive resistance is by 4.2 times higher than the value of acting σ y and, according to this factor, siltstone maintains continuity through all its thickness. When approaching the 1 6 c seam, vertical stress concentration increases and is already Ky = 1.9-2.7. Based on the account and analysis of these factors, one can assert that the roof of the seam and the seam itself are not destroyed.Practical value. Technological solutions have been developed for mining the protecting pillars to increase the completeness of coal reserves extraction while reducing its production costs and increasing the safety of stope operations by means of decreasing the rock pressure onto powered support.

Methodology for adapting the results of laboratory research on coal gasification to full-scale conditions

“…Сьогодні з високим ступенем ефективності адаптацію та аналіз отриманих результатів щодо реальних умов при підземній розробці родовищ корисних копалин можливо забезпечити шляхом проведення моделювання у відповідних CAD та САЕ пакетах [11][12][13]. Існує низка програм, що дозволяють здійснювати дослідження на основі числових методів.…”