Saint-Petersburg Mining University, Saint Petersburg, Russian Federation:

Sidorenko A. A., Associate Professor, Candidate of Technical Sciences, sidorenkoaa@mail.ru
Sishchuk J. M., Associate Professor, Candidate of Philology, julia.sishchuk@spmi.ru
Gerasimova I. G., Associate Professor, Candidate of Pedagogical Sciences, irishkags@ya.ru

The foreign and Russian practices of mining of closely spaced coal seams are reviewed. The outcomes of the research accomplished by the USA National Institute for Occupational Safety and Health are generalized. It is found which geological and geotechnical factors govern safety and efficiency of mining of closely spaced coal seams. It is shown that the majority of accidents are connected with the influence of high stress zones generated by coal pillars left between longwalls. Methods to ensure stability of longwalls, assembling and disassembling chambers in mining of closely spaced coal seams in USA are described. The emergency situations due to destruction of longwalls in the influence zones of high stresses generated by pillars left in the upper seams are analyzed. For validation of the layout of underground excavations, in terms of Kirov Mine and using the Guidelines on Rock Bolt Support Design and Application in Coal Mines in Russia, the values of roof subsidence are calculated and plotted for different layouts of excavations with rock bolt support. Numerical investigation of stress state of overmined rock mass is presented for the conditions of Kirov Mine. It is shown that the most hazardous situation takes place when it is required to ensure safety of longwalling in the lower lying seam under the joint influence of previously mined out longwall and pillar in the upper lying seam. It is concluded on possible arrangement of longwall in the zone of high stresses in Kirov Mine, and it is recommended to shift headings beyond the high stress zone influence. Also, recommendations are given on economically efficient and safe mining of closely spaced coal seams. The areas of the further research are specified.

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