The transformation of the stress condition of embedded border diastrophic bloc rock of the «pillar-working» system is considered, in combined action of geostatic tension, lateral and transversal tension wave, generated by rock bump. It is supposed that the tension wave front are parallel to the adjacent strata media discontinuity. Under this condition, in the article the influence of the critical tension levels on the roof and pillar rocks stress condition.
The transformation of potentially dangerous zone of wrecks accumulation in the layeredroof of the mining system is considered, in the time of combined action of geostatic pressure and tension shok wave. The explosion wave front is suggested to be parallel to the proximate handing roof environs discontinuity. Under this condition in the article is considered the influence of levels of critical stress and the depth of opening location on the change of implicitly dangerous zone of faults accumulation in the layers of the root stone.
The mass velocity diagrams transformation in the layered border zone of the mining system in the time of tension explosion waves influence is considered. The explosion wave front is suggested to be parallel to the proximate handing roof environs discontinuity. Under the admitted assumption the mass velocity epures transformation is investigated in the layered roof stone of the mining system and in the dividing pillar.
An approach to the estimation of amplitudes, periods and durations of elastic seismic waves, both longitudinal and transverse, generated by rock impacts characterized by dedicated energy is proposed. Calculations of stress and mass-velocity diagrams of elastic seismic waves from rock impacts are given, and a comparison of the calculated and real diagrams of a rock impact characterized by an energy of 10 kJ is given.
On the basis of linear equations of stability theory, design experiments modeling the combined effect of stresses and steady seismic longitudinal and transverse waves generated by rock impacts with energy of 10-100 kJ on the mine workings have been carried out.
The article describes the main periods of life and creativity of Professor A.M. Zhuravsky, who headed the Department of Higher Mathematics for more than 30 years. His contribution to the organization of methodical and scientific activities at the department and the defense potential of the country is noted.
The problem is posed and calculations of stresses and weight coefficients in laminar roof at rock fracture are carried out. The calculations showed that increasing the energy of rock fracture reduces the influence of diffraction processes. The condition of brittle fracture of rock roof under dynamic loading is obtained.
The joint influence of static and dynamic stress field on work is considered. The study of such influence on work is based on the previously formulated methodological principles of mathematical modeling of physical processes in complex systems.
This paper deals with the modeling study of the refraction process of a plane compressive wave by a system of a fissile homogeneous medium. It is assumed that the wave front is parallel to the inter-surface boundaries of the medium. The solution of the problem is obtained using a numerical finite-difference method.
In this paper, the joint effect of static and dynamic stress fields on the excavations is considered, and tensile stress regions in the contour zones of the excavations are modeled.
The joint impact of static and dynamic stress fields on the mine workings is considered, tensile stress zones are determined, and the process of brittle failure of rock in the contour areas of the mine workings is modeled. The study of such influences on the mine workings is based on the methodological principles of mathematical modeling of physical processes in complex systems formulated in the article [1].
Blast wave influence on rock stability in mine openings is given an account of. Results of mathematical modelling of a dynamic stress field created in the massif due to wave interaction with the mine opening have been analysed. A stress field influenced by short wave blasts has been studied. Equations of dynamic balance for theoretically elastic environment, supplemented with boundary and initial conditions for the corresponding components of stress tensor, serve as the basis of a mathematical model developed by V.V. Karpenko and G.A. KoIton. The set of 5 equations was solved using S.K. Godunov numerical technique. Input data are assumed on the basis of the mining conditions at the Severniy (Northern) mine (blast hole diameter - 76 mm; blast type - granulite AC-8). A particular case of blast influence at 10 m range between the charge and the gallery roof (r =370) has been studied. Distribution diagram parameters of the forward-moving elastic wave compression phase have been determined using analytical dependence for a cylinder-shaped charge blast (amplitude σ o = 9.6 MPa, period of time t - 1.2 ms, speed C 1 - 4500 m/s). It has been demonstrated, that form the direction of the forward-moving wave, refracted and diffracted waves create in the massif an extensive zone of radial tension stress, peaking at 1.6 at the distance of 0.8-1.0 R from the contour. In lateral areas, the blast wave produces concentration of tangential compression stresses up to 1.6 σ o . An estimation of mine destruction caused by the energy of dynamic development has been given. Besides dynamic compression and tension stresses, repeated blasts and impulse stress load and relief on the massif also influence stability of the mine openings. An estimation of rock stability criteria at the entry contour during joint action of static and dynamic stresses has also been given.
Finite-difference and numerically analytical methods for solving dynamic and elastic-plastic problems of geomechanics are proposed. Using the finite difference method and on the basis of the principles of the mathematical modeling of physical processes the tensor components, which characterize the dynamic stress field in rocks around the vaulted excavation of the type under the oblique action of the stress wave on it, were determined. An iterative process, which allows calculating the components of the stress tensor and the velocity of the plastic flow of rocks around mine workings at great depths, is designed with the help of numerical analytical method. Reliability and validity of the method is confirmed by comparing the obtained calculations with the results of solutions found by other authors and experimental data.
The problem of resource saving when mining diamond-bearing kimberlites at the Udacha open pit of ZAO Udachinsky GOK is extremely relevant, since in the last decade there has been a stable tendency of reducing the quality of commercial products - diamond crystalline raw materials. Examination of the character of damages of diamond monocrystals suggests that the technological defects of crystals are caused, first of all, by the pulse mode of loading crystals of host rocks at the stages of explosive destruction, mechanical crushing and grinding of kimberlite ore at the crushing and milling equipment. This is evidenced by the nature of damage to diamond single crystals manifested in crushing, shear and chipping cracks. The highest damageability occurs in medium and large diamonds, especially of the +2 class. In its turn, according to the CCA, taking into account the cost of diamonds of different size and quality groups, 1% increase in preservation allows to get an additional profit of about $7 million. ALROSA's efforts are aimed at improving the natural preservation of rough diamonds, which is why research has been resumed to predict the parameters of stress waves that are potentially dangerous in terms of damage to the rough diamonds. Since kimberlites are breccia and tuff-like rocks with rather homogeneous properties in layers with different elevations, which tend to increase acoustic stiffness with depth of occurrence, they can be considered as layered homogeneous isotropic elastic media.
