scholarly journals Management of geomechanical processes - the basis for selecting the optimal technologies for the development of mineral deposits

2018 ◽  
Vol 56 ◽  
pp. 02005
Author(s):  
Anatolii Kozyrev ◽  
Iuliia Fedotova ◽  
Eduard Kasparyan
Keyword(s):  
Rock Mass ◽  
Stress State ◽  
Rock Massif ◽  
Mineral Deposits ◽  
Mining Operations ◽  
Mining Technology ◽  
Geomechanical Monitoring ◽  
Gas Dynamic ◽  
Natural Stress ◽  
Mining Methods

When carrying out mining operations, a rock massif responds to technological impacts in the form of developing strains and fractures. Under certain conditions, this response occurs as dynamic and gas dynamic destructions of rocks with intensive release of energy, which creates threats to security and disrupts a working technology. To substantiate the optimal mining technology, which would be maximum adequate to the specific geological and geomechanical conditions of a deposit development, it is necessary to organize a comprehensive monitoring of geomechanical processes in rock massifs. The paper considers general principles to organize the geomechanical monitoring under conditions of the hierarchically-blocked rock massifs in the gravitational-tectonic field of the natural stress state. The authors give main recommendations for managing geomechanical processes in the rock mass for various mining methods.

scholarly journals Development of methods for assessing the mine workings stability

2020 ◽  
Vol 201 ◽  
pp. 01040
Author(s):  
Arstanbek Abdiev ◽  
Rakhat Mambetova ◽  
Aziz Abdiev ◽  
Sher Abdiev
Keyword(s):  
Rock Mass ◽  
Stress State ◽  
Surface Relief ◽  
Experimental Studies ◽  
Geological Structure ◽  
State Assessment ◽  
Mining Operations ◽  
Research Results ◽  
Mine Workings

This paper studies the rock mass stress state under highland conditions, depending on the geological structure of a particular rock mass area, the tectonic field of stresses and the region relief. This study is aimed to develop an experimental method for assessing and monitoring the properties and state of the rock mass adjacent to mine workings. Experimental studies are performed through stresses measurements in-situ. Based on research results, it has been revealed that the geological structures, tectonic fields of stresses and the earth’s surface relief of the deposit normally reflect the values and direction of the main stresses acting in the mass. These patterns can be used to predict and assess the stress state of the rock mass. During the mass stress state assessment, quantitative dependences have been obtained for determining the stress tensors conditioned by the overlying rocks weight, tectonics and fracturing, and the deposit surface relief The research results make possible to assess the nature of the stresses distribution, to identify the areas of reduced, equal, increased and maximum stresses concentration of the virgin mass, as well as to increase the efficiency of the geoacoustic control developed by the authors for the state of the mass adjacent to mine working. According to the new patterns and dependences obtained, the values and directions have been scientifically determined of the main stresses action, as well as the zones of stresses manifestation. These patterns and dependences are valuable for designing and planning the development of mining operations.

Investigation of features of shock wave distribution in the rock massif at gas dynamic phenomena

2020 ◽  
pp. 234-243
Author(s):  
S.I. Skipochka ◽  
◽  
T.A. Palamarchuk ◽  
L.V. Prokhorets ◽  
V.P. Kurinnyi ◽  
...  
Keyword(s):  
Shock Wave ◽  
Wave Propagation ◽  
Shock Waves ◽  
Shock Wave Propagation ◽  
Rock Massif ◽  
Mining Operations ◽  
Technological Factors ◽  
Gas Dynamic ◽  
Methane Mixture ◽  
Dynamic Phenomena

When studying risk factors in coal mines, it is necessary, in the first place, to consider factors and properties of the rock massif occurred with the deepening of mining operations in the coal mines, and determine one of the main types of danger: risk of geodynamic phenomena. The geodynamic phenomena occur and develop under the influence of natural and technological factors. Natural factors determine the rock massif proneness of ato geodynamic manifestations or, in other words, its potential danger due to these phenomena. Occurrence of this danger depends on technological factors. Among the dangerous factors of underground coal production to which primarily belong the geodynamic phenomena, the main ones are gas-dynamic phenomena, which are the most complex by their nature and dangerous by consequences due to high dynamic power and release of great amount of gas during a short period of time. Their consequences can be accidents due to sudden gassing and blockage of workings by coal and rock, explosions of methane and coal dust, destruction of the roadway supports, damage of machines and mechanisms, equipment and devices. As the gas-dynamic phenomena in the rocks massif are accompanied by occurrence of various processes differed by their nature, therefore, risks caused by them should be taken into account at mining operations. When considering the gas-dynamic phenomena attention should be paid to the shock wave propagation, as it is one of the gas dynamic processes. Therefore, purpose of this research was to study specific features of the shock wave propagation in the rock massif in order to prevent dangerous consequences. In this article, the authors consider the processes which occur in the rock massif prone to dangerous gas-dynamic phenomena at the shock wave propagation. The methods of rock mechanics, mechanics of continuous media, gas and thermodynamics were used in the research. Analytical researches of processes and numerical analysis of the received results were carried out. It is shown that a sharp increase of thermodynamic parameters under the action of gas-dynamic phenomena can lead to occurrence of the shock waves. It is further established that an explosive air-methane mixture can be formed in cracks, cavities and pores of the face area. At opening the cavities and pores, cases of shock waves formation in air-methane mixture leading to its detonation are possible. Under adverse conditions, this phenomenon can lead to a fire in the roadway.

scholarly journals Theoretical aspects of monitoring synergistic processes in the rock massif

2019 ◽  
Vol 109 ◽  
pp. 00067
Author(s):  
Tetiana Palamarchuk
Keyword(s):  
Stress State ◽  
Electric Fields ◽  
Synergistic Effects ◽  
Rock Massif ◽  
Physical Parameters ◽  
Mining Operations ◽  
Wave Nature ◽  
Established Relationship ◽  
Relationship Of ◽  
Time Continuum

In this article, the grounds for considering of rocks massif as a nonlinear medium with dissipative properties have been shown that as a result of the combined influence of normal and tangential stresses around the workings, synergistic effects are observed with the formation of similar structures, which leads to the appearance of a quasi-stationary damped stress wave, and this , in turn, makes it possible to predict the nature of changes in the stress-strain state of the rock massif in space-time continuum. Taking into account the influence of the mining operations speed, a theoretical justification for diagnostics the physicomechanical properties and the stress state of sedimentary rocks has been developed by using the dynamic and kinematic characteristics of acoustic and electric fields. The theoretically established relationship of the stress state of massif of quartz-containing rocks with its elastic and electrical parameters follows taking into account the damped wave nature of the processes around the mine workings. Obtained results indicates the principal possibility of quantitative assessment of stress components acting in the rock massif using determined physical parameters of the massif.

Numerical investigation of the geomechanical response of adjacent backfilled stopes

2015 ◽  
Vol 52 (10) ◽  
pp. 1507-1525 ◽  
Author(s):  
Nooshin Falaknaz ◽  
Michel Aubertin ◽  
Li Li
Keyword(s):  
Rock Mass ◽  
Stress State ◽  
Friction Angle ◽  
Critical Issue ◽  
Surrounding Rock ◽  
Filling Sequence ◽  
Natural Stress ◽  
Simulation Results ◽  
Backfill Strength ◽  
Backfilled Stopes

Backfilling of mine stopes helps provide a safe workplace underground. The interaction between the backfill and surrounding rock mass has to be evaluated to ensure the secure application of backfill. This critical issue has led to much research on the stress state in single (isolated) backfilled stopes. However, the stress distribution in multiple openings that interact with each other has not yet been investigated as thoroughly. In this paper, the authors are using numerical simulations to evaluate the response of two adjacent backfilled stopes created in sequence, with a new assumption that is based on an explicit relationship between Poisson’s ratio and the internal friction angle of the backfill; as shown here, the use of this relationship can significantly modify the stress state in backfilled stopes. The simulation results, presented in terms of stresses, displacements, and strains, illustrate the influence of different parameters including backfill strength, pillar width, stope depth, rock mass stiffness, natural stress state, and excavation and filling sequence. Complementary aspects are also considered. A discussion follows on some of the characteristics and limitations of this investigation.

Studies of the Stress State of the Coal Pillar between the Treatment andPreparatory Workings by the Methods of Deformable Body Mechanics

2020 ◽  
pp. 26-31
Author(s):  
N.V. Cherdantsev ◽  
Keyword(s):  
Rock Mass ◽  
Stress State ◽  
Coal Seam ◽  
Solid Mechanics ◽  
Boundary Integral Equations ◽  
Coal Pillar ◽  
Boundary Integral ◽  
External Boundary ◽  
Mining Operations ◽  
Coal Rock

To ensure safe conditions for mining operations and increase labor productivity, a reliable assessment of the stress state of the coal-rock mass is required. The model is presented concerning the geomechanical state of the massif hosting the coal seam, treatment, and preparatory workings. The model is developed based on the fundamental methods of solid mechanics and ensures a computational experiment and the reliability of the results. Stress distribution in the coal-rock mass in the vicinity of the in-seam workings was calculated in two stages. First, the stress field in the edge zones of the coal seam and in the collapsed rocks was determined by the methods of mechanics of the flowing medium. Distribution of stresses in the extremely stressed zones of the seam and the layer of collapsed rocks behind the working excavation was found by the method of characteristics by solving differential equations of the hyperbolic type. They are obtained based on the of the joint solution of the equilibrium equations, general and special Coulomb — Mohr criteria of the transition of the seam and the collapsed layer, as well as their contacts with the lateral rocks to the limiting state. Then, by replacing extremely stressed zones of the coal seam and the layer of the collapsed rocks with stresses acting at the contacts with the surrounding massif, the problem is reduced to the integral equation of the second external boundary value problem of the theory of elasticity. It is solved by the method of boundary integral equations. Insignificant influence of changes in the angle of internal friction of the collapsed rocks on the parameters of the seam bearing pressure in the vicinity of the treatment and development workings is shown. However, it significantly effects on the bearing pressure in the extremely stressed zone of the collapsed rocks layer.

scholarly journals Dynamics of vibratory partitioned feeders for the uranium ore drawing and feeding

2019 ◽  
Vol 109 ◽  
pp. 00023
Author(s):  
Vitalii Dyrda ◽  
Anatolii Kobets ◽  
Viktor Pukhalskyi ◽  
Yurii Kozub ◽  
Oleksandr Chernii
Keyword(s):  
Rock Mass ◽  
Labor Intensity ◽  
Mining Operations ◽  
Mining Technology ◽  
Uranium Ore ◽  
Discharge Opening ◽  
Continuous Mining ◽  
Elastic Couplings

In this paper, the authors consider dynamics of partitioned vibratory feeders with rubber elastic couplings. Use of vibratory feeders (including partitioned ones) and schemes for the ore vibrating drawing, feeding and loading in underground conditions allowed to mechanize one of the most time-consuming and dangerous processes of uranium ore mining and to solve the following problems: to improve effectiveness of the lumpy rock mass drawing and loading by 2.5-3 times; to increase intensity of mining operations and reduce life of the excavation blocks and horizons; to reduce labor intensity and cut cost of the process of ore drawing and loading; to improve uniformity of the rock-mass outflowing from the discharge opening and to reduce by 3-5 times frequency of the large-lump material freezing (use of partitioned feeders reduces number of freezes by 25-60 times); to increase size of commercial lump panels; practically to exclude traumas during the process of ore drawing and loading (usually, it presents 30-60 % of all traumas caused by the underground operations); to mechanize process of ore drawing and loading, and to create conditions for implementation of low-waste cyclic-and-continuous mining technology.

scholarly journals Assessment of gas-dynamic danger of Krasnoslobodsky fracture zone of Starobinsky potash deposit

2019 ◽  
Vol 64 (2) ◽  
pp. 240-252
Author(s):  
P. A. Vityaz ◽  
I. I. Golovaty ◽  
V. Ya. Prushak
Keyword(s):  
Rock Mass ◽  
Fault Zone ◽  
Fracture Zone ◽  
Functional System ◽  
Geological Structure ◽  
Gas Filtration ◽  
Mining Operations ◽  
Gas Dynamic ◽  
Hydrodynamic Systems ◽  
Dynamic Phenomena

Gas-dynamic danger of Krasnoslobodsky fracture zone in Starobin Deposit of potassium salts was investigated. The study was carried out taking into account the existing ideas about the mechanism of formation of foci of gas-dynamic phenomena in the salt rock mass of the field, as well as taking into account the results of seismic and hydrogeological studies of the fault zone and the revealed patterns of distribution of gas-dynamic phenomena over the field area. The features of the geological structure of Krasnoslobodsky fracture zone in the upper salt stratum containing layers of potash ore are established. The features of the mechanism of evolution of hydrodynamic systems in fault zones are revealed. It was found that the functional system of halogen metasomatosis in these zones of the rock mass was not shielded, so that the absorption zone of the hydrodynamic system was located in the rocks of the clay-marl strata located above the upper salt strata and horizons of possible mining operations, and fractured rocks of the fault zone provided gas filtration from the system of voids formed during the evolution of hydrodynamic systems. According to the results of the study, it was concluded that in Krasnoslobodsky fracture zone within the upper salt layer there were no conditions for the formation of dangerous foci of gas-dynamic phenomena, such as sudden emissions of salt and gas and collapse of roof rocks. Accordingly, there is a possibility of safe mining operations, such as the penetration of intersecting workings through the fault zone.

scholarly journals The reasoning of mining methods parameters toward development of the apatite-nepheline ore deposits based on results of forecast of massif stress state

2018 ◽  
Vol 56 ◽  
pp. 01019 ◽  
Author(s):  
Ilya Bagautdinov ◽  
Anton Kuranov ◽  
Nikita Belyakov ◽  
Anatoly Streshnev
Keyword(s):  
Numerical Simulation ◽  
Stress State ◽  
Numerical Model ◽  
Ore Deposits ◽  
The Finite Element Method ◽  
Mining Operations ◽  
Sublevel Caving ◽  
Local Areas ◽  
Mining Methods ◽  
The Given

The article describes the experience in which the argumented parameters of the sublevel caving system in the conditions of mining operations take into account the Khibiny apatite-nepheline deposits. The stress state of the massif under the given conditions is determined by the parameters of the initial gravitational-tectonic field stresses, which have a complex distribution and redistribution for each individual isolating situation, which, in turn, is determined by the zone of the bearing pressure from the overlying stages. The necessary consideration of the factors indicated determined the order of the research: the parameters of regional field stress should be determined using the global numerical model of the deposit; after this, in order to justify the parameters of mining methods in local areas, it is necessary to make local numerical simulation for each area. All calculations were performed using Simulia Abaqus software, which implements the finite element method. Thus, the article presents numerical simulation of the stressed state of the massif of areas of “Plato Rasvumchorr” and “Apatitovii Tsirk” deposits and further describes the order of intersection of the results with the help of a global numerical model to a local numerical model of stope block at + 310 m at the Rusvumchorr mine. There are fixed minimum pillar sizes according to the accepted mining method in numerical simulation results using multiscale models.

Degassing Drilling as an Effective Way to Unload Carbonate Reservoirs of the Host Rock Mass of Primary Diamond Deposits

2021 ◽  
pp. 88-94
Author(s):  
A.M. Yannikov ◽  
◽  
A.V. Kharchenko ◽  
Keyword(s):  
Rock Mass ◽  
Gas Flow ◽  
Gas Production ◽  
Underground Mines ◽  
Mining Operations ◽  
Two Stage ◽  
Significant Drop ◽  
Gas Dynamic ◽  
Geological Conditions ◽  
Under Construction

The issues are considered related to gas manifestations during the development of primary diamond deposits in Yakutia — «Internatsionalnaya» and «Udachnaya» pipes, which are the most difficult in terms of gas-dynamic conditions. Gas manifestations at the field are associated to a greater extent with gases dissolved in the natural brines, and to a lesser extent — with free and sorbed gases. Due to the fact that when developing the underground mines, the sources of explosive gases were recorded, to ensure the safe conduct of mining operations it is required to unload the rock mass. Analysis of data obtained at the different stages of construction and operation of the fields identified the source of the recorded gas manifestations: reservoirs and local gas reservoirs filled with gas-saturated brines. It was revealed that the sources of gas release are zones consisting of cavernous and fractured carbonate rocks complicated by fracturess and low-amplitude tectonics. The analysis of the dynamics of changes in the gas-dynamic, hydrogeological and mining-geological conditions of mines allowed to propose a two-stage advanced degassing of the host rocks as a rather effective method of combating gas manifestations. At the first stage, vertical advance wells are drilled for the entire capacity of the production block. At the second stage, 3–7 horizontal and slightly inclined (up to 10°) wells are drilled in front of the borehole of the underground working under construction. Thus, there is an interval unloading of the massif and the involvement of undeveloped natural gas reserves at the first stage. Actual observations of gas inflows in the underground mine workings showed a significant drop in gas production rates. In such a way, at the «Internatsionalnaya» mine the average gas flow rate per well (per year) decreased from 12.67 to 1.06 m3/h, which confirms the success of the selected two-stage degassing.

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