National Mineral Resources University (University of Mines) (Saint-Petersburg, Russia):

Zubov V. P., Professor, Doctor of Engineering Sciences, e-mail: spggi_zubov@mail.ru
Karpov G. N., Assistant Professor

Raspadskaya–Koksovaya CJSC (Mezhdurechensk, Russia):
Polosukhin S. V., Deputy Director for Mining

Higher engineering level mines as a rule carry out operations on a seam with a single longwall fitted out with a high performance mechanized mining equipment. The topical problem in such mines is cutting of time spent for assembling and dismantling of the equipment when it is to be moved to new working areas. The assembling and dismantling period in Kuzbass mines is 16–152 days, which appreciably exceeds the required period for dismantling of mechanized equipment (11–16 days). Economic disbenefit due to the out-of-service time of the mechanized mining equipment reaches 30–34 million roubles a day. Essential loss of time during the equipment dismantling in longwalls is because of the need to settle additional support and eliminate after-effects of roof rock collapse in a dismantling chamber during its drivage and in period of removal of powered support from it. The cause of the top failure in dismantling chambers and the large duration of disassembling is the high damage ratio in the seam roof rocks due to rock fracturing ahead of breakage face at the final work stage characterized by the low velocity advance of the face. Among the accident-preventive measures recommended for cutting the duration of the assembling and dismantling, there are the increase in the face advance at the final work stage, advanced stress redistribution in the areas adjacent to development headings and the use of self-propelled powered supports that ensure more efficient roof support in places of its most probable collapse.

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