Geomechanical monitoring of the rock mass state is an actively developing branch of geomechanics, in which it is impossible to distinguish a single methodology and approaches for solving problems, collecting and analyzing data when developing seismic monitoring systems. During mining operations, all natural factors are subject to changes. During the mining of a rock mass, changes in the state of structural inhomogeneities are most clearly manifested: the existing natural structural inhomogeneities are revealed; there are movements in discontinuous disturbances (faults); new man-made disturbances (cracks) are formed, which are accompanied by changes in the natural stress state of various blocks of the rock mass. The developed method for evaluating the results of monitoring geomechanical processes in the rock mass on the example of the United Kirovsk mine of the CF AO Apatit allowed to solve one of the main tasks of the geomonitoring system – to predict the location of zones of possible occurrence of dangerous manifestations of rock pressure.
One of the most reliable methods for assessing the physical and mechanical properties of rocks as a result of their destruction are laboratory tests using hard or servo-driven test presses. They allow to obtain reliable information about changes in these properties beyond the limit of compressive strength. The results of laboratory tests of rich sulfide ore samples are presented, which made it possible to obtain graphs of their extreme deformation. Both monolithic samples and samples with stress concentrators in the form of circular holes with a diameter of 3, 5 and 10 mm were tested. It was revealed that during the destruction of the samples, the modules of elasticity and deformation decrease by 1.5-2 times, and in the zone of residual strength – by 5-7 times.
In the article, within the framework of the dynamic theory of elasticity, a mathematical model of the impact of seismic blast waves on rock mass is presented, including a working. The increase in the volume of mining operations in complex mining and geological conditions, taking into account the influence of the explosion energy, is closely connected with the analysis of the main parameters of the stress-strain state of the rock massif including a working. The latter leads to the need to determine the safe parameters of drilling and blasting operations that ensure the operational state of mining. The main danger in detonation of an explosive charge near an active working is a seismic explosive wave which characteristics are determined by the properties of soil and parameters of drilling and blasting operations. The determination of stress fields and displacement velocities in rock mass requires the use of a modern mathematical apparatus for its solution. For numerical solution of the given boundary value problem by the method of finite differences, an original calculation-difference scheme is constructed. The application of the splitting method for solving a two-dimensional boundary value problem is reduced to the solution of spatially one-dimensional differential equations. For the obtained numerical algorithm, an effective computational software has been developed. Numerical solutions of the model problem are given for the case when the shape of the working has a form of an ellipse.
The article deals with the questions related to the development of math models of nonlinear strain deformed conditions of a laminar heterogeneous rock mass in the area of excavation in shallow formations. The non-linear relations between physical strains and deformations are added to the basic system of resolving differential equations in partial derivatives (equilibrium equations) and well-known Cauchy dependencies (formulas of connection between deformations and displacements). This ratio is defined by both the elastic potential and by exponential law of hardening or by linear hardening law. Within the framework of the accepted hypotheses of Genki – Ilyushin theory of small elastoplastic deformations some algorithms and calculating complexes of solutions of applied geomechanics problems have been developed. They include such numerical methods as finite difference method, finite element method, and boundary element method. Nonlinear boundary problem based on Newton – Kantorovich – Raphson linearization method comes to the iterative process of a linear boundary problems sequence solution.
Mathematical modeling of the impact of blast waves on the underground pipeline was composed from general equations of continuum mechanics, shell theory and hydraulics equations. The problem is formulated in the plane formulation for direct integration of the native system of equations chosen method of finite differences. At the contact of the array and the pipeline, boundary conditions of slippage and rigid clamping are considered.
The variety of the mining and geological conditions with further increasing in depth of the development of bedded deposits leads to necessity for the analysis of stress and strain state near different types of excavations.
The nonlinear problem of analysis of the stress-and-strain state of rock massif is discussed. The numerical algorithm analysis of the stress-strain state of a massif, which includes a set of computational methods, is suggested.
This article is devoted to the algorithm of the forecast of stress and strain state nonho-mogeneous layered physical nonlinear rock massif. The modeling based on applying the whole package of computational methods: variational method, discrete continuation on numeric parameter method, quasi-linearization of nonlinear value boundary problem, finite difference method, Thomas algorithm and iterative process.
Diamond is special mineral in comparison with others. Diamond is a precious stone and also technical raw material. Native diamond deposits of GRO «MIBA» are kimberlitic pipes. Assess the expediency of cut mines of them by group of open-cast mines in modern economic situation is urgent scientific task. For solving this problem it is necessary to take into account the possibilities of minimization of transport expenses to provide some concentrating mills with raw materials.
In this paper we propose a method for assessing the impact of blasting operations in the pipeline, which is based on mathematical modeling of the joint fluctuations of pipeline and soil during the passage of seismic waves from blasting. The calculation was performed in a plane problem, the soil was modeled Winkler elastic foundation, piping – a geometrically nonlinear shell. The numerical implementation was carried out using an iterative algorithm.
The approach is considered according to seismic stability of pipelines at conducting explosive works borehole charges or at influence of natural earthquake. In this paper independence of fluctuations of support of the pipeline is considered also.
The methods of mathematical models estimation of ship elements technical state were worked out in this work. The latter were realized for different conditions of ship elements work.
The analysis of stress-strain state near excavations was carried out in this work as applies to coal and salt deposits. The indirect boundary element method was used as a tool of research.
Development of bedded deposits is associated with man-caused distortion of specific environment – the rock massifs, which are very complicated in their composition, can vary significantly in mechanical properties and is characterized with a wide variety of laws and techniques to assess its stress-strain state.
The variety of the mining and geological conditions with further increasing in depth of the development of bedded deposits leads to necessity for the analysis of stress-strain state near different types of excavations.
The analysis of stress-strain state near excavations and influence of goafs on its redistribution were carried out in this work as applies to coal and salt deposits. The indirect boundary element method was chosen as a tool of research.
С развитием вычислительной техники в математическом моделировании наряду с традиционными аналитическими методами все шире применяются численные методы. Среди численных методов решения наиболее широко известны метод конечных разностей, метод конечных элементов, метод граничных элементов, метод граничных интегральных уравнений и другие методы, получившие большое распространение в инженерной и научной среде. К числу наиболее эффективных численных методов относится МКР, широко используемый при решении важных прикладных задач геомеханики.
При ведении горных работ в массиве горных пород происходит нарушение естественного напряженно-деформированного состояния. Для расчета параметров напряженно-деформированного состояния в массиве горных пород могут применяться различные эффективные численные методы: конечных разностей, конечных элементов и граничных элементов. Было рассмотрено влияние технологических схем отработки запасов на напряженно-деформированное состояние массива соляных пород Старобинского месторождения на затухающей стадии ведения горных работ.
Работа посвящена обоснованию применения удлиненных кумулятивных зарядов на открытых и подземных горных работах. Уточнена аналитическая зависимость длины трещины от геометрических параметров заряда, шпура и физико-механических свойств горных пород.
During mining operations, the natural stress-strain state of the rock massif is disturbed. Various numerical methods can be applied to calculate the parameters of the stress-strain state of the rock massif: finite difference method, finite element method, boundary element method, the application of the last of which is described in this paper. The problem of deformation distribution around records of different configuration drifting in an elastic, homogeneous, isotropic rock massif is described. The indirect method of fictitious stresses and the method of boundary integrals are used to solve this problem.
This paper deals with issues related to mathematical modeling of optimization of stretched shaped charge parameters on the basis of similarity test. By means of the numerical method of random search the necessary rational parametric variables for designing rational designs of stretched shaped charges are obtained.
Mining of reservoir fields is associated with technogenic "perturbation" of a specific environment - a rock massif. This object is very complex in structure, different in mechanical properties and characterized by a wide variety of laws of change of its stress-strain state (SSS). Obviously, the study of parameters of mechanical processes in such media cannot be methodologically predetermined by the use of data only from full-scale experiments, or data only from laboratory studies or the results of analytical calculations.
Проектирование и строительство шахт, горных выработок и возведение подземных сооружений на большой глубине в различных горно-геологических условиях - сложные процессы, связанные с анализом параметров напряженного и деформированного состояния в выработках. Существует множество различных методов определения геомеханических параметров. Основными методами определения напряженного и деформированного состояния являются геологоразведка, инженерная физика, экспериментальные исследования, механика сплошной среды.
The rock in a rock mass is in a tense equilibrium. This equilibrium is usually broken when mining operations are stopped. There are many theories related to rock pressure in the stoping zone. Obviously, the solution of problems on this subject is associated with the study of deformation and dislocation processes of rocks in the workings and mine shaft. Since it is difficult to conduct grandiose full-scale experiments, these problems have to be solved by new developed methods, which are very universal and informative.
The article deals with the development of mechanics as a science in its historical development up to the beginning of XX century. The peculiarity of the historical development of mechanics is due to the development of technology. At the initial stage till the end of XVIII - beginning of XIX centuries technique was ahead of mechanics development, and then with the development of differential and integral calculus mechanics begins to be ahead of technique and provides its further development. The article reexamines the phases of development of technique and mechanics, while noting the trends in the development of individual sections of mechanics. Due to the emerging needs of mining, both simple and compound machines (pumps, winders, blowers, etc.) arise and are improved. With their appearance arises the need for their maintenance and repair. Special attention is paid to the contribution of Russian scientists and inventors to the progress of engineering and mechanics.
This paper deals with the formation of various scientific societies, their influence and role for the development of fundamental and natural science disciplines. Some aspects of the development of such a fundamental science as mathematics, starting from the moment of its origin and up to the present time, are considered in sufficient detail.
A numerical and analytical method for solving nonlinear geomechanics problems has been developed. This method is based on the combination of the Vlasov variational method, the Newton-Kantorovich linearization method and the method of general iterative process. The physical nonlinearity of the rock deformation process is considered in the framework of the main hypotheses of small elastic and plastic deformation Genki-Ilyushin.
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 influence of various factors on the condition of the edge zone of the coal seam ahead of the face during the development of flat seams is assessed. All the variety of factors can be divided into mining-geological and mining-technical. Of mining-geological factors, the greatest influence on the coal deformation in the peripheral zone have such factors as power, depth of development, dip angle, presence of interlayers, of mining-technical - face length, speed of its movement, development system, type and power characteristics of the support, method of rock pressure control.
An algorithm for selecting a mathematical model of the rock massif is presented. The finite difference method is used as a numerical solution method. The case of nonlinear rock deformation process is considered.
The modern coal mines work at great depths, characterized by high natural gas content of the massif, which increases the intensity of gas release at high rates of movement of the working faces. A brief review of the experience of operating coal mines at great depths is given. The main directions of improvement of technological schemes of mine working areas are proposed.
A mathematical model of interaction of a multilayer massif with a thin coal seam, including initial resolving differential equations and boundary conditions, has been obtained. The developed algorithm of numerical solution is implemented in a computational program in which the input parameters are geological characteristics of the main and immediate roof, stiffness coefficient of the coal seam in the massif and the law of its change in the edge zone, stiffness coefficient of soil rocks, stiffness coefficient of fill material, layer thickness and ultimate deformations of the roof. Accordingly, the output parameters of the calculation program are: the response of the coal seam to the action of the load from the overlying massif (support pressure), vertical and angular displacement of the roof layers over the coal seam, vertical and angular displacement of the roof over the mined-out space, the ultimate span of the roof.
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.
Designing of mine workings, mining, construction of underground structures of various purposes at great depths and in difficult mining and geological conditions is closely connected with the task of defining the stress-strain state (SSS) of rock massifs.