On the basis of the measurements and computer modeling the dependences of the formation of the expected stresses on the contour of preparatory mine workings have been established. The main regularities of mine workings displacement depending on their location relative to the coal seam are taken into account. Graphs of displacement of roof rocks and soil are given. The questions of stresses redistribution in the vicinity of mine workings are considered and the ways of their stability are determined on the basis of analysis of methods and means of impact on the contour massif.
The methods of determining the parameters of anisotropy of rocks, containing mine workings, the nature of the deformation of rocks in the contour zone during elastic-plastic deformation are shown. The issues of determining the shapes and sizes of inelastic deformation zones depending on the physical and mechanical properties of rocks, the depth of mine workings and the size of the cross-sectional section are considered.
Based on the analysis of mining and geological conditions of the Eastern Donbass offered a method of determining the value of the expected displacement of the contour of preparatory workings depending on their location relative to the excavation work. The graphs of displacement of roof rocks, changes of displacements of rocks in front and behind the face depending on the different resistance of the lining are given. Considered the formation of zones of broken rocks in the vicinity of mine workings and identified ways to ensure their stability.
The need to use pillarless technology in the development of shallow coal seams by underground mining at depths greater than 500 m is dictated by the economic feasibility of reducing the cost of coal and reducing losses in the subsurface. Traditional pillarless methods of protection often do not satisfy the existing conditions or are used irrationally. The combination of rigid protective structures with slotting by means of hydraulic fracturing or micro-hydrotorpediting of roof rocks is, in our opinion, one of the promising directions of ensuring the operational condition of preparatory mine workings. Analysis of the modern state of the protection methods of preparatory mine workings used repeatedly is executed, protective actions for conditions of the Eastern Donbass, grounded by results of the study of the mechanism of change of the stress-deformation state around the mine working away of the adjacent faces are recommended.
