Floor rolling querschery and rolling shoes with the transition to the underlying floors are used as ventilation.
The time of working out one layer within the floor for each layer is different and ranges from 3 to 5 years, working out one floor lasts 5-7 years.
The central geological and industrial area is the oldest industrial district of Donbass. The coal mining industry in the area began to develop around 1870. Metallurgical, chemical and machine -building enterprises arose on the basis of coking coals of this area.
The Central District has a dense network of railways and belongs to the most populated areas of the country.
When practicing the retinue layers in the central district of Donbass, concentrated deformations in the form of ledges and cracks occur on the earthly region of Donbass. On the earth’s surface, these ledges are manifested in two types:
Flaps facing the exit – direct ledges;
in the opposite direction – reverse ledges.
Direct ledges are formed when one layer of thickness, more rigid, freezes, and the other, less rigid, continues to bend towards the developed space. The formation of direct ledges is usually accompanied on the earth’s surface by the appearance of cracks. Reverse ledges are formed when the layers of breeds are bent according to each other in the direction of contact. In the Central District, such ledges have a predominant distribution.
Repeated part -time work causes further development of cracks and ledges formed during primary part -time work. The concentration of deformations in the places of formation of cracks reduces deformation in areas between cracks. The distance between cracks and ledges in the central district of Donbass fluctuates approximately – from 20 to 60 m. The direction of cracks and ledges in terms of the direction of extending the layers, which makes it possible to determine in advance the likely location of their trace from neighboring areas.