Purpose. To develop a mathematical model of the interrelated processes of coal-rock mass deformation and water filtration in the disturbed area to study the change in the value of water inflow into the mine working de-pending on the method of its supporting. Methods.In this research, we used methods of rigid body mechanics, fluid and gas mechanics as well as numerical simulation based on the finite element method. Findings.A mathematical model of water filtration in the deformed rock mass was developed. It is shown that the use of bolting prevents fracturing process in the zone subjected to the influence of the mine working. In this case, solidity of the virgin mass in the roof is maximally preserved. Significant reduction of the filtra-tion area and decrease in its permeability leads to the drop in intensity of the liquid filtration movement and prevents or reduces water inflow into the mine workings with anchor support.Originality. Bolting is considered as a technological method of reducing water inflow into mine workings for the first time. Based on the results obtained, the "Method for Reducing Water Inflow into the Mine Workings with the Roof Bolting" was developed. Effectiveness of this method was proved in the coal mines of the Western Donbas.Practical implications. The calculations show that bolting can simultaneously perform two functions: ensuring stability of the mine working and its waterproofing, which significantly reduces the operating costs.

The mathematical model has been developed for the coupled processes of the rock massif deformation and gas filtration in a disturbed area around mine working, in the bottom of which there are hard and soft gas-bearing rocks. When solving the problem, the finite element method was used. The calculation results of the displacements, stresses and pressures of methane in the studied area are represented in the paper. It is shown that the difference in the physical and mechanical properties of the bottom rocks of mine working causes the non-uniform distribution of geomechanics and filtration parameters. In more strong sandstone, the stresses concentration increases. Therewith, an intensive process of fractures formation takes place in the argillite and the coal. Methane from the upper part of the gas-bearing sandstone is filtered into the mine working, the destruction of the coal interlayer is accompanied by release of methane and its accumulation under the layer of a strong sandstone. The development of a zone of inelastic deformations leads to the destruction of sandstone. In case of brittle destruction, with the formation of fractures of a certain length, a breakthrough of methane may occur out of the bottom into mine working.

Purpose. To substantiate the informative parameter, to develop the method and equipment for non-destructive testing (NDT) of rock bolt fastening, as an element of geomechanical monitoring of the mine workings state.Methods. Analytical and bench experimental testing of shock-wave processes in the "rock bolt -bonding layerrock massif" system.Findings. It has been established, that the non-destructive shock-wave method is the most satisfying for monitoring the geomechanical state of the "rock bolt -bonding layer -rock massif" system. This method is based on the registration and analysis of rock bolt oscillations, caused by non-normalized hit to the rock bolt end. It has been confirmed, that the most informative parameter is the relaxation time, that is the time over which the amplitude of oscillations decreases by "e" times. It has been shown, that clamping of the resin-grouted rock bolt in massif and its tensioning affects the relaxation time of damped oscillations. Furthermore, the relaxation time is inversely proportional to the degree of the rock bolt clamping, and is linked linearly with an increase in the rock bolt tensioning. The spectral composition of wedge shaped rock bolts self-oscillations, which are caused by impact excitation, depends both on the nature of clamping and on the rock bolt length, and makes it possible to identify the rock bolts by their length.Originality. The existence of a special type of damped longitudinal oscillations of the rock bolt in viscoelastic medium of the bonding layer has been established. The relaxation time of the specified type of oscillations was chosen as an informative parameter. An analytical link has been established between the informative parameter of shock-wave method of monitoring and the main indicators of rock bolt fastening quality: the degree of adhesion with massif and tension value.Practical implications. The method has been improved and equipment has been developed for non-destructive testing of rock bolt fastening, which makes it possible to control in-situ the rock bolt fastening quality, including the geomechanical state monitoring of mine workings.

Purpose. The research purpose is to develop a geomechanical model for ensuring the safety of mining operations by determining the optimal slope angles and probabilistic assessment of the stability of the open-pit walls. Methods. Three-dimensional geomechanical models for surface mining of deposits have been developed based on calculations of the stability factor (safety factor SF) of the open-pit walls in the Rocscience program to determine the rock mass stress-strain state at the end of mining using the finite element method. The geological wireframe model (GWM) has been built on the basis of the available geological sections, horizon plans and the results of the engineering-geological surveys using the Surpac geoinformation system. Findings. Strength reduction factor (SRF) has been determined taking into account the physical-mechanical properties of rocks that constitute the near-wall mass. An assessment of the stability of walls according to the selected geological sections is given, taking into account the projected contour of the Severny Katpar open-pit walls. The calculation of the projected contour stability of the open-pit walls by several different methods has revealed that the open-pit walls are generally stable. The open-pit parameters at the end of mining have been determined. Originality. For the first time, it has been determined that in the Southern and South-Western area of the Severny Katpar open-pit wall in the horizons +700…+400, there is a decrease in SF from 1.18 to 1.41 due to the predominant occurrence of siltstones and tectonic disturbances of the walls. Practical implications. The mathematical calculation results of the stability of the projected contour walls in the Severny Katpar open pit have been generalized. In addition, a geological and structural wire-frame model of the deposit has been developed, which makes it possible to ensure the safety of mining operations in the open pit.