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An analytical method is presented for determining the stress state of a rock mass in the vicinity of a circular opening, taking into account the influence of contact anchors with high rigidity. The method is based on the solution of a plane problem from the elasticity theory about the equilibrium of a weighty isotropic medium with a circular hole, around which there is a certain region reinforced with an arbitrary number of radially installed rods with high rigidity. The calculation examples illustrating the possibilities of the method are presented. For the purpose of comparison, the corresponding results of computer modeling using the finite element method are considered.

The problems of calculating the stress-strain state of an ore body, enclosing and backfilling masses during the development of mining operations at deep horizons are considered. The previously developed algorithm for taking into account the sequence of stoping and backfilling operations to redistribute the stress fields in rocks for modeling the nonlinear properties of backfilling material has been modernized. The calculation is carried out by the method of conic elements using the stiffness matrix formed for an intact rock mass. The nonlinear behavior of backfilling material is taken into account using the initial stress procedure that is also used to model the sequence of sinking and backfilling of stopes.

The results of mathematical modeling of permafrost rock mass deformation around a mine working with circular cross-section are presented and the influence of thawing on stress state of the rock mass and mine working stability in conditions of a hydrostatic stress field is studied. It is shown that there is a critical size of the thawing halo, upon exceeding which the working starts loosing stability .

The issues concerning the influence of temperature factor on safety and efficiency during the underground mining of mineral deposits in the areas with permafrost rocks are set forth. The features of mining operations and the formation of a thermal regime in alluvial mines of the permafrost zone have been determined. It is shown that the main requirement for regulating the thermal regime of a mine is to prevent thawing of dispersed rocks surrounding mine workings. The results of predictive calculations (by the method of mathematical modeling) of the temperature regime in air supply workings, as well as in enclosing rock mass of a designed alluvial mine, are presented. The results of mathematical modeling of the temperature regime of soils in the area of pile foundation of a tower-type drop hammer and the mouth of a vertical shaft are considered. Based on the results of numerical modeling, recommendations are given to organize automated control of soil temperature (horizontal wells) of the wellhead.

The parameters of physical, mechanical, rheological and water properties of clay rock in the Kara-Keche coal quarry are presented. It is found that in relation to water, gray clay is a swelling-proof and impervious rock. Its presence at the boundary of slip line surface contributes to the activation of landslide phenomena in the open-pit sides. It is determined that gray clay has a pronounced rheological ability to develop plastic flow deformations. The dependence of effective viscosity of gray clay on humidity value was revealed. It is shown that theoretical and experimental values of effective viscosity are in good agreement.

The behavior of cohesion coefficients and internal friction angles depending on the linear or nonlinear representation of the Mohr envelope as a functional dependence of the shear stress on the normal stress is studied. The calculations were based on the reference data concerning ultimate compressive and tensile strength of rocks. The linear dependence was constructed as a tangent drawn to two Mohr circles, and nonlinear dependence - as a relationship recommended by the domestic standard.

The problem of penetrating a weighty rock mass with the Coulomb-Mohr plasticity condition with a rigid nondeformable wedge-shaped tool is being solved. In this case, the relations on the characteristics, as a consequence of differential equilibrium equations, are obtained by the terms that identify them with ordinary linear differential equations of the first order. As a result of equation integration, the required values of contact stresses at the “tool-rock” interface are determined. The ultimate load depends both on the angle of tool sharpening and physical/mechanical rock characteristics, and the depth of penetration.

In the axisymmetric case of Leibenson - Ishlinsky formulation, the problem of stability loss in a mine working with initial circular cylindrical shape is solved. It is assumed that at the moment of stability loss bulges are formed, facing the inside of the mined-out space. The rock mass around the mine working is considered in one of three states: elastic, elastoplastic and post-limiting deformation. The critical load depending on the length of working, radius and physical/mechanical rock properties is determined.

It is shown that inhomogeneity of the structure and variability of the rock mass properties has a great influence on the mining efficiency of complex deposits, which include the section Uregolsky of the open pit mine Kiyzassky. Field observations were carried out to assess the state of the rock mass on the overburden benches of the working side of the mine, which showed constant differences in their structure and texture along the mining front. The expected differences and variability of the physical and mechanical properties of rocks were confirmed by the laboratory study of rock samples taken from the open-pit face. It is found that natural geological inhomogeneity of the overburden properties significantly affects the sequence and processes of drilling, blasting, excavation, transportation and dumping operations. Fracturing of the rock mass enhances the influence on these processes, general and local geomechanical stability of mine workings.

The trends of improving the technology of stope mining are determined, taking into account the design parameters of geotechnology and the figure of ore drawing. Efficient options of sublevel caving with rock preparation and rock pillar above the drill haulage horizon, as well as ore pretreatment are considered.