Supporting a Mine Working with a Shelter in Various Mining and Geological Conditions

Abstract

Shelters are used to protect miners from exposure to harmful gases and for the work of rescuers. Such shelters are built in a niche adjacent to the mine working. The purpose of this work is a numerical study of the stress state of a coal-rock massif with a mine working and a shelter, their stability in various mining and geological conditions and with various supporting schemes.
Numerical simulation of the stress state of a coal-rock massif with a mine working and a shelter was performed; their stability was studied in various mining and geological conditions and with various supporting schemes. It is shown that, over time, near-contour rocks are unloaded from rock pressure, and an area of increased difference of the stress tensor compo-nents expands around the mine working and the shelter. This leads to cracks formation of varying degrees of intensity. When the mine working with the shelter is driven at a shallow depth in hard rocks, the basic scheme, which consists mainly of metal frames and a reinforced concrete barrier, is sufficient for their supporting. If the host rocks are weaker, the stability of the mine working and the shelter is broken and it is necessary to strengthen their supporting with rock bolts. In the bolted area, the rocks are in triaxial compression conditions, a rock-bolts arch is formed above the mine working and the shelter, which pre-vents the displacement of the roof rocks into the mine working and increases its stability. With an increase in the depth of min-ing operations, the stability of the mine working decreases; the inelastic deformation zone in the mine walls grows; the load on the support increases. For the rock-bolts arch formed in the mine roof, supports are required in the walls of the mine working and the shelter. For this purpose, side rock bolts are installed. The use of an appropriate supporting scheme leads to a de-crease of the area of inelastic deformation zone by 2.5 times and the area of the zone unloaded from rock pressure by 2.6 times. Thus, such schemes for supporting the mine working and the shelter are selected, which ensure their stability in the con-sidered mining and geological conditions.