Purpose. To reduce risk of emergency and injury-risk situations while improving the methods for predicting stressstrain state of the rock mass with the help of information systems, and to detect fissure locations in the mine roadways with the help of radiometric control.Methods. Analysis and generalization of experimental data; mathematical modeling of geomechanical and filtration processes by means of the finite element method; underground investigations of changes in activity of α-radiation of certain radon-isotope in the atmosphere of the mine roadways using standard methods as well as radiometric control equipment; and statistical processing of measurement results.Findings. Ratios, determining correlation between parameters of geomechanical process (i.e. fracture porosity, inclination angles of the fracture networks and their strike) and parameters of gas-dynamic process (i.e. intensity, gas flow rates and direction of gas travel) have been obtained. A mathematical model based on the finite element method is proposed in which a reasonable assumption is made that deformation of the pore medium is equal to the varied volume of the pore and fracture area. In the context of the model, deviation part of the strain tensor determines changes in the shape of the rock mass elements during disintegration. Spherical part of the strain tensor characterizes changes in volume and permeability of the pore and fracture area; it is determined by a value of minimum principal strains of the model elements. Parameters of the pore and fracture area location, volume and permeability were substantiated in the rock mass. The mine investigations have helped determine that within the areas of geological dislocations, concentration of radon daughter decay product of alpha-radiation polonium (Po 218 ) experiences more that 2 -4 times increase in relation to the roadway average value. On the basis of the criterion, it is proposed to use radiation monitoring of the mine roadways to identify areas of newly formed fracture systems resulting from fracture system deformation as one of the elements of method for the integrated control of the rock mass state. Originality. For the first time, regularities of changes in the pore and fracture area shape and volume at different stages of the adjacent longwall mining have been determined basing on parameters of technogenic fracture system orientation and spherical part of the strain tensor. The method of controlling the safe state of rocks has been further developed; it differs in the use of the determined ratios between changes in fracture system parameters and changes in α-radiation activity of some radon isotopes, methane concentrations and their correlation.Practical implications. The research results have been applied for the development of analytical and experimental approach to control safety of production environment in mines.

The article is devoted to development of methods for geofiltration calculations with taking into account peculiarities of changes of the rock physical and mechanical properties at water saturation. Methods: mathematical modeling of geomechanical and filtration processes with the help of finite element method and laboratory and underground studies. A mathematical model was formulated for solving a problem of elasticity theory by the finite element method, which took into account peculiarities of water-saturated rocks. Pattern of stress-strain state changing in the fractured water-saturated rocks under the action of critical loads, which occurred around the preparatory roadways during their operation, were established. In order to solve the filtration problems, a bank of collected initial data on physical and mechanical properties of water-saturated rocks was processed with the help of variation coefficients, which were taken into account by the method, which assumed calculation of the model loading with critical parameters. * Corresponding author: OASlashchova@nas.gov.ua

The article is devoted to solving of a live scientific problem of improving methods for predicting stability of mine roadways under mining-and-geological conditions of the rock watering. Specific effect of water on the rock strength properties was investigated. The generalized correlation dependences of the strength reduction of sandstones, mudstones and siltstones at their saturation with water relatively to their initial strength in natural state were obtained. By method of mathematical modeling, regularity of changes in the stress-strain state of the rock massif depending on rate of preparatory roadway watering were established and confirmed by the mine observations. The correlations were proposed for calculating probable water inflows into the mine roadways basing on the assessment of volume of broken elements in the geomechanical model, parameters of open porosity and fracturing. It is stated that implementation of a set of measures aimed at reducing water flows into the mine roadway improves its stability due to the smaller size of inelastic deformation zones in the walls and roof of the mine roadway in the stationary abutmentpressure zone, reduced contours of the mine roadway deformation, and decreased rate of horizontal and vertical convergence. * Corresponding author: OASlashchova@nas.gov.ua