scholarly journals Effect of increasing mining rate on longwall coal mining – Western donbass case study

2016 ◽  
Vol 38 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Olena Sdvyzhkova ◽  
Renata Patyńska
Keyword(s):  
Coal Mining ◽  
Strain State ◽  
Rapid Change ◽  
Rock Stress ◽  
Strength Theory ◽  
Mining Operations ◽  
Stress Strain ◽  
Statistical Strength ◽  
Roof Collapse ◽  
Stress Strain State

Abstract This paper presents the problems associated with the rapid change of the rock stress-strain state in terms of increasing the rate of coal mining. Parameters of the roof collapse are determined depending on the rate of a longwall advancing under conditions of poor rocks. Statistical data are processed to obtain a general trend concerning the mining rate impact on the roof collapse. The statistical strength theory is applied to explain the increase in mined-out space and the size of hanging roof behind a coal face. Numerical simulation is carried out to determine a critical size of mined-out space that provokes a roof collapse. The area of yielded rocks is outlined using the criterion developed taking into account the rate of longwall advancing. A general regularity is obtained to determine the roof collapse parameters. The developed technics gives a possibility to predict the moment of general roof collapse at the initial stage of longwalling to prevent the negative effect of the rapid stress redistribution provoking joints propagation and intensive gas release. The estimation of the rock stress-strain state considering the rate of mining operations can be useful for tasks related to a new technology implementation. The statistical strength theory and failure criterion applied together provides adequate planning of mining activities and the assessment of natural hazards.

Modeling of the stress-state longwall face during coal mining with the technology of roof management complete drop and stowing

2020 ◽  
pp. 99-106
Author(s):  
I. E. Mazina ◽  
A. A. Stel’makhov ◽  
L. F. Mullagalieva
Keyword(s):  
Coal Mining ◽  
Strain State ◽  
Underground Mining ◽  
Negative Impact ◽  
Hydrological Regime ◽  
Coal Bed ◽  
Stress Strain ◽  
Environmental Friendliness ◽  
Modeling And Analysis ◽  
Stress Strain State

Underground mining of coal deposits has a negative impact on all components of the environment. When developing a coal deposit, it is coal mining technology that determines the scale and consequences of the negative impact. Changes in the stress-strain state of the geo-environment can lead to a violation of the hydrological regime, increased gas emission from the host rocks, the initiation of gas-dynamic processes. Choice of roofing management technology - as a geotechnological method of natural and technical system management determines the environmental friendliness of coal mining and creates safety conditions. The article deals with the technology of roofing control during coal production. For this purpose mathematical modeling and analysis of stress-strain state of the bottomhole part of the coal bed for the conditions of S.M. Kirov is performed. As a result of modeling, two technologies of roof control were analyzed - complete caving and stowing. For the worked out clearing leaves filled with either caving rocks or stowing material, there are characteristic unloading zones in the massif to be worked and overworked, as well as pressure reference zones, which fall on the parts of the pillars associated with the lava. It was found out that the application of the stowing technology creates conditions for minimization of gravitational stresses in the geoenvironment, as well as significantly reduces the potential energy of form change.

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.

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 Laws of gas draining in the massif disturbed by mining operations

2019 ◽  
Vol 109 ◽  
pp. 00047
Author(s):  
Serhii Kurnosov ◽  
Volodymyr Zerkal
Keyword(s):  
Strain State ◽  
Abutment Pressure ◽  
Gas Permeability ◽  
Experimental Studies ◽  
Rock Massif ◽  
Gas Release ◽  
Mining Operations ◽  
Stress Strain ◽  
Stress Strain State ◽  
The Impact

A method for calculating gas permeability of the rock massif depending on its stress-strain state is presented. By using methods of the mine experimental studies, influence of mining operations in the adjacent long walls on intensity of gas release from the previously worked-out long-pillar was determined, as well as impact of the massif stress-strain state on efficiency of the drainage boreholes. Formulas were obtained for calculating coefficients of the impact of zones with static and dynamic abutment pressure on intensity of gas draining in the previously worked-out long-pillar.

scholarly journals STUDY OF THE INFLUENCE OF PARAMETERS TECHNOLOGICAL SCHEMES OF EXCAVATION ON THE SUSTAINABILITY OF MINE ROADWAYS WHEN IMPLEMENTING THE CONCEPT OF «SMALL MINES»

2020 ◽  
pp. 64-73
Author(s):  
Svitlana Sakhno ◽  
◽  
Victoria Borodich ◽  
Yevhen Karlov
Keyword(s):  
Coal Mining ◽  
Strain State ◽  
Point Of View ◽  
Practical Significance ◽  
Stress Strain ◽  
Stress Strain State ◽  
Rock Stability ◽  
Complex Mechanization ◽  
Mine Roadways ◽  
First Time

Purpose. Investigation of the influence of the parameters of technological schemes of coal mining on the stress-strain state of the rocks containing the mine roadways in the implementation of the concept of «small mines». Methods. The study used the finite element method and the analysis method. Modeling was carried out by the method of dangerous sections. According to the first variant of the technological scheme, two dangerous sections were selected, according to the second – four. The solution of the problem was carried out in a volumetric setting with observance of the boundary conditions. Results. The analysis of the stress-strain state of the rocks around mine roadways, according to the compared options, made it possible to determine the expected state of the rocks and establish the parameters of the zones of possible destruction. From the point of view of rock stability at the stage of elastoplastic deformation of rocks, the compared options are almost equivalent. Taking into account the shorter time of maintenance of roadways, it is more expedient to use short longwalls. In this version, trapezoidal support is used as the main fastening in the roadways, and in the “traditional” version – metal arch support. It is shown that with significantly lower costs for maintaining mine roadways, their stability when using short-longwall technological schemes is better. The studies carried out make it possible to assert that for “small mines” with small production, technological schemes with short longwalls are more appropriate than the “traditional” technological schemes developed for complex mechanization. Scientific novelty. The study of the stress-strain state of rocks around mine roadways of various shapes and sizes during the analysis of technological schemes for coal mining with short longwalls made it possible to establish the orientation and parameters of the massif sections that pass into an out-of-bounds state. This was done for the first time for the conditions of the Ukrainian Donbass. Practical significance. The availability of information about the expected stress-strain state of the rock mass allows timely planning of methods of fastening and measures to increase the local stability of rocks. Keywords: stresses, deformations, development, coal mine, technological schemes of excavation.

scholarly journals Geodynamic risks of mining in highly stressed rock mass

2019 ◽  
Vol 129 ◽  
pp. 01011
Author(s):  
Arkadiy Shabarov ◽  
Anton Kuranov ◽  
Anton Popov ◽  
Sergey Tsirel
Keyword(s):  
Strain State ◽  
Fault Zones ◽  
Main Attention ◽  
Mining Operations ◽  
Stress Strain ◽  
Specific Strength ◽  
Near Fault ◽  
Stress Strain State ◽  
Structure Assessment ◽  
The Stability

The paper discloses that geological faults and phenomena associated therewith are the main risks of mining. The phenomena of fault activity and specific features of near-fault zones, determining their impact on the stability of mine workings and other man-made objects are discussed in detail. Different sections of faults are classified according to the degree and types of risk. The main attention is paid to the most stressed zones, where the fault is a closely spaced crack in the rock, characterized by specific strength and rock-bump hazard effect. The paper discloses that although mining operations change the stress-strain state of the massif, nonetheless, most of hazardous situations and geodynamic phenomena during excavation occur in tectonically stressed zones that already existed in the massif. In these areas, man-made overload during mining results to the formation of extremely stressed geodynamically hazardous zones. Thus, geodynamic zoning, which includes the identification of faults and block structure, assessment of their activity, as well as reconstruction of the stress-strain state of both the blocks and the near-fault zones, is the key method for assessing risks of geodynamic phenomena.

scholarly journals Improvement of gas field efficiency through the controlling of rock stress-strain state in the bore-hole working area

2019 ◽  
pp. 4-19
Author(s):  
A.F. Bulat ◽  
◽  
І.M. Slashchov ◽  
O.A. Slashchovа ◽  
S.Yu. Makeiev ◽  
...  
Keyword(s):  
Strain State ◽  
Rock Stress ◽  
Stress Strain ◽  
Gas Field ◽  
Stress Strain State ◽  
Field Efficiency

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

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