scholarly journals Geomechanics of overworked mine working support resistance in the laminal massif of soft rocks

2020 ◽  
Vol 201 ◽  
pp. 01003
Author(s):  
Iryna Kovalevska ◽  
Hennadii Symanovych ◽  
Jacek Jarosz ◽  
Mykhailo Barabash ◽  
Oleksandr Husiev
Keyword(s):  
Mine Working ◽  
Computational Experiment ◽  
Strain State ◽  
The Finite Element Method ◽  
Mining Operations ◽  
Soft Rocks ◽  
Second Stage ◽  
Support Resistance ◽  
Complicating Factors ◽  
Water Cut

The relevant issues of ensuring trouble-free mining operations on the underlying horizons, which are partially or fully overworked are studied in this paper. The problem has been solved using the example of a laminal massif of the Western Donbas soft rocks; complicating factors were taken into account: water-cut, fracturing, and the rheological properties manifestation. The model, proposed for calculation, has been substantiated in view of geomechanics, as well as the finite element method has been chosen to obtain the stress-strain state of the adjacent massif and support. At the first stage, mine observations of the state of mine working planned for overworking have been conducted and analysed. At the second stage, a computational experiment has been conducted in the most difficult areas. The stresses fields have been analysed according to vertical, horizontal and stresses intensity components of the soft rocks laminal massif, as well as their distribution curves for the recommended and basic fastening options. It has been proved that the recommended parameters of the fastening structure provide repair-free mine working maintenance for the entire exploitation period with account of overworking. Recommendations have been developed for mining the seam C6 in M.I. Stashkova Mine, DTEK Pavlohradvuhillia PJSC.

scholarly journals Development and testing of an algorithm for calculating the load on support of mine workings

2021 ◽  
Vol 15 (1) ◽  
pp. 1-10
Author(s):  
Volodymyr Bondarenko ◽  
Iryna Kovalevska ◽  
Frederick Cawood ◽  
Oleksandr Husiev ◽  
Vasyl Snihur ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Support System ◽  
Mine Working ◽  
Strain State ◽  
The Finite Element Method ◽  
Load Bearing ◽  
Geological Conditions ◽  
Mine Workings ◽  
Roof Rocks

Purpose. The purpose is to develop the calculation methods for minimizing the load on the fastening system of the preparatory mine working in difficult mining and geological conditions of its maintenance. Methods. By analysing the multivariate computational experiments on the study of the stress-strain state of the load-bearing elements of the ‘massif – support’ system in the preparatory mine workings by means of the finite-element method, as well as mine observations and measurements of displacement in the coal-overlaying rock formation. Findings. An algorithm has been developed for searching the rational modes of the fastening system resistance and methods for minimizing the load on the support of the preparatory mine working, maintained in very complex mining and geological conditions. Originality.The methodical principles have been developed of minimizing the load on the fastening system of the preparatory mine working, which are based on the use of a combination of stress-strain state studies of the ‘massif – support’ system by means of the finite element method and provisions of normative documents for calculating the dimensions of the dome of natural equilibrium of the mine working roof rocks. Practical implications. The operation modes optimisation of the load-bearing elements interaction of the mine working fastening system reduces the material and labour costs during its construction and increases its stability during operation. Keywords: analysis, calculation, optimization, support, preparatory mine working, stope works, roof rocks, collapse

scholarly journals Water stability influence of host rocks on the process of water filtration into mine working with frame and roof-bolting support

2019 ◽  
Vol 109 ◽  
pp. 00041 ◽  
Author(s):  
Viktoriia Krukovska ◽  
Yurii Vynohradov
Keyword(s):  
Mine Working ◽  
Water Pressure ◽  
Water Inflow ◽  
Water Filtration ◽  
Water Stability ◽  
The Finite Element Method ◽  
Mining Operations ◽  
Roof Bolting ◽  
Host Rocks ◽  
Roof Rocks

The water stability influence of host rocks on water filtration process from the undermined aquifer to the mine working, depending on the way of its fastening has been studied in the paper. When solving the problem of water filtration in a deformable massif, the finite element method was used. The results of calculations are presented of the filtration permeability of the coal-bearing massif, the water pressure and the value of the water inflow into mine working in the cases of mining operations in sandstone and argillite. It is shown that the use of roof-bolting support prevents the development of the fractures formation process in the mine working roof, preserving the rocks in a natural, monolithic state. As a result, the process of water filtration from water bearing rock layers is constrained, which prevents or significantly reduces the soaking of border roof rocks. The use of roof-bolting fastening several times reduces the water inflow into mine working, located even in water-permeable rocks. The application of the roof-bolting support as a technological method for reducing the water inflow into mine workings has been substantiated.

Photomechanical investigation of the stress—Strain state of a precast-block support in a mine working

1980 ◽  
Vol 16 (1) ◽  
pp. 6-10
Author(s):  
V. F. Trumbachev ◽  
O. K. Slavin ◽  
G. K. Kuchuashvili
Keyword(s):  
Mine Working ◽  
Strain State ◽  
Stress Strain ◽  
Stress Strain State

Research of throwing areols of underground pipeline in permafrost

2021 ◽  
pp. 21-30
Author(s):  
T. S. Sultanmagomedov ◽  
◽  
R. N. Bakhtizin ◽  
S. M. Sultanmagomedov ◽  
T. M. Halikov ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Experimental Study ◽  
Finite Element ◽  
Strain State ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Loss Of Stability ◽  
Underground Pipeline ◽  
The Finite Element Method ◽  
Permafrost Thawing

Study is due to the possibility of loss of stability of the pipeline in the process of pumping a product with a positive operating temperature and the formation of thawing halos. The article presents the ways of solving the thermomechanical problem of pipeline displacement due to thawing. The rate of formation of a thawing halo is investigated depending on the initial temperatures of the soil and the pumped product. The developed monitoring system makes it possible to study the rate of occurrence of thawing halos in the process of pumping the product. An experimental study on the formation of thawing halos around the pipeline was carried out on an experimental model. A thermophysical comparative calculation of temperatures around the pipeline on a model by the finite element method has been carried out. Keywords: underground pipeline; permafrost; thawing halo; monitoring; operating conditions; stress–strain state.

scholarly journals MODEL OF DEFORMATION OF FIBROUS MATERIALS OF MULTIDIRECTIONAL REINFORCEMENT WITH NONORIENTED FIBERS

2021 ◽  
Vol 1 (37) ◽  
pp. 119-129
Author(s):  
E. Shikula
Keyword(s):  
Strain State ◽  
Fibrous Composite ◽  
Theory Of Elasticity ◽  
Fibrous Materials ◽  
Thermoelastic Properties ◽  
Fibrous Composite Material ◽  
Conditional Moments ◽  
Second Stage ◽  
Two Stages ◽  
Nonlinear Theory Of Elasticity

A model of deformation of multidirectional reinforcement fibrous materials with differently oriented fibers is proposed. The solution to the problem is built in two stages. At the first stage, the known properties of fibers and binder are used to determine the effective thermoelastic properties and stress-strain state of the subsystem with fibers oriented in a certain way relative to the main coordinate system. It is based on stochastic differential equations of the physically nonlinear theory of elasticity using the method of conditional moments. At the second stage, using a given distribution function based on the Voigt scheme, a model of deformation of the entire system is constructed from the calculated properties of the subsystems. Strain curves are obtained for simple loading, and the deformation of materials at uniform orientation of fibers is investigated. It was found that a fibrous composite material with differently oriented fibers in a macrovolume is isotropic, and its effective thermoelastic constants substantially depend on the volumetric content of fibers.

scholarly journals The stress-strain state simulation for the auger-boring machine’s support-guide system

2021 ◽  
Vol 315 ◽  
pp. 03008
Author(s):  
Aleksei Khoreshok ◽  
Leonid Mametyev ◽  
Oleg Lyubimov ◽  
Andrey Kuznetsov ◽  
Yunliang Tan
Keyword(s):  
Computer Modeling ◽  
Strain State ◽  
Technical Solution ◽  
Mining Operations ◽  
Stress Strain ◽  
Stress Strain State ◽  
Guide System

The article deals with a number of important aspects of the aggregate-modular type auger-boring equipment creation, as an integral part of the range of tunneling complexes for mining operations and laying horizontal and slightly deviated holes for various purposes. The importance of improving the support and guide systems, characterized by a variety of configurations and sizes, a large number of elements for various purposes and with different responsibility degree, is noted separately. In this regard, the possibility of flexible refinement of the complexes configuration for specific boring conditions with the verification of each applied technical solution by computer modeling remains relevant. The ways for a new constructive solutions creating are outlined.

scholarly journals Choice of technologies of ensuring exploitation suitability of buildings in the underground construction area

Vestnik MGSU ◽  
2020 ◽  
pp. 452-461
Author(s):  
Emil Imran Оglu Alirzaev ◽  
Marina E. Dement'eva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
The Finite Element Method ◽  
Underground Construction ◽  
Underground Structures ◽  
Stress Strain ◽  
Computer Complex ◽  
Stress Strain State ◽  
Element Method

Introduction. One of the serious problems in the construction of underground structures in a dense urban area is the occurrence of excess deformations of the foundations of operating buildings that fall into the zone of influence of underground construction. The subject of the study was the calculated justification of the modern technology of compensatory injection. The relevance of the task is determined by the fact that the choice of the most effective protection technology should be based not only on a comparison of technological precipitation with maximum permissible values, but also on the assessment of the possibility of monitoring and controlling the movements of the foundations of buildings and structures during construction and subsequent operation. The purpose of the study was to compare various methods of protecting the foundations of existing buildings and structures and justify the selection of the most effective of them for further implementation and dissemination in the design and construction of urban underground structures. Materials and methods. On the basis of the survey data of the operated building falling into the impact zone of excavation of the pit for the construction of the installation and shield chamber of the subway, the parameters of the stress-strain state of its foundations are studied by mathematical modeling. The problem was solved by the finite element method based on the software and computer complex Z_Soil v.18.24. Results. Based on the analysis of the results of the examination of the administrative building using the finite element method, a change in the parameters of the stress-strain state of the foundations was modeled with various technologies for strengthening it. In the course of solving the geotechnical problem, it was found that the minimum impact on the foundations of the building during the construction of the pit was obtained in the method of compensatory injection. The system of criteria for making a decision on choosing an effective way to ensure the suitability of buildings in the underground construction zone for operation is substantiated. Conclusions. The results of this work can be used to justify the choice of technology for prevention and control of excess deformations of foundations. The function for calculating the volume of injected material in the Z_Soil software and computer complex can be used to justify the consumption of materials and the economic efficiency of the technological solution.

Improving Safety when Extracting Water-soluble Ores by Optimizing the Parameters of the Backfill Mass

2021 ◽  
pp. 53-59
Author(s):  
M.M. Khayrutdinov ◽  
◽  
Ch.B. Kongar-Syuryun ◽  
A.M. Khayrutdinov ◽  
Yu.S. Tyulyaeva ◽  
...  
Keyword(s):  
Strain State ◽  
Raw Materials ◽  
Research Work ◽  
Integrated Approach ◽  
Water Soluble ◽  
Mining Operations ◽  
Stress Strain ◽  
Mining System ◽  
Stress Strain State ◽  
Geological Conditions

The results of the scientific and research work devoted to modeling the stress-strain state of the mining system of an underground mine using the finite element method in the FLAC3D software are presented in the article. The possibility of using room-and-pillar mining with backfill with the abandonment of chain pillars is justified. The results are presented concerning the research results of the quantitative assessment of the mass using the von Mises equation and Norton' power law of creep to estimate the contour stress. It becomes possible to determine the sequence of mining of the deposit area and the stage-by-stage filling of the stopes at the stage of mining design due to the high accuracy of modeling the stress-strain state of the mass near mining operations using FLAC3D software. The proposed approach is possible when evaluating the geotechnical state of the rock mass when using the mining systems with various methods of support of the mined-out area: natural; artificial; with the collapse of ores and enclosing rocks, as well as when calculating the combined method of deposit development. A differentiated approach to assessing the state of the mass is possible considering difficult mining and geological conditions, conditions of increased rock pressure, abundant water influx, increased fracturing of rocks by introducing additional conditions into the model depending on its geotechnical state. Variant of the comprehensive exploitation of mineral resources was proposed considering the total value of natural and man-made geo-resources of the area being mined. The possibility of rational use of the mined-out space with the use of various positive qualities of geo-resources at their manmade transformation is also considered. An assessment of the mineral and raw materials potential of the mined area is given with a proposal for the prospects of increasing the integrated approach of excavation, increasing the life of the mining enterprise and the complexity of developing this area.

scholarly journals Annual production enhancement at deep mining

2019 ◽  
Vol 123 ◽  
pp. 01043 ◽  
Author(s):  
Nataliia Shvaher ◽  
Tetiana Komisarenko ◽  
Serhii Chukharev ◽  
Svitlana Panova
Keyword(s):  
Iron Ore ◽  
Underground Mine ◽  
Annual Production ◽  
Direct Proportion ◽  
Operating Life ◽  
Mining Operations ◽  
Deep Mining ◽  
Second Stage ◽  
Mining Depth ◽  
Mining Enterprise

The article aims at determining possible annual production considering mining and technical capabilities of the underground mine. Deepening of mining operations at Kryvyi Rih iron ore basin reduces considerably annual production of the useful mineral which results in increased mining costs. To maintain annual production, it is reasonable to build the second stage of opening the depth of which depends on production volumes. When determining the optimal depth of the first stage opening, it is necessary to apply a complex research method including the graphoanalytical one for determining the underground mine’s annual production and the industrial one for adjusting the methods considering technical conditions of the enterprise. It has been determined that annual production is influenced not only by mining and geological but also by mining and technical conditions. It has been proved that annual production of an underground mine decreases in direct proportion to the increased depth of mining. The speed of skips in the shaft is greatly impacted by the length of the main opening and its operating life. With the increase of the shaft operating life the skip speed decreases from 12 to 6 – 8 m/s. When designing the flowchart of further opening of underlying levels, it is necessary to consider both mining capabilities and technical conditions of the shaft and headgear, mining depth and the main opening operating life as well as the strategy of the mining enterprise. Consideration of the above mentioned factors enables maintaining the required annual production when mining iron ores at great depths. Under conditions of Kryvyi Rih iron ore basin, it has been determined reasonable to apply the main vertical shaft flowchart when mining reserves to the depth of 1650 m.

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