scholarly journals Geophysical signs of hard rock disturbance

2020 ◽  
pp. 58-65
Author(s):  
Diakov A. Iu ◽  
Keyword(s):  
Rock Mass ◽  
Wave Field ◽  
Hard Rock ◽  
Quantitative Estimation ◽  
Geological Structure ◽  
Study Data ◽  
Open Pit ◽  
Electromagnetic Signal ◽  
Mining Operations ◽  
Stability Parameters

Introduction. Development of deep open pits requires reliable knowledge on conditions of rocks at the hard rock mass to locate potentially hazardous sectors which have considerable impact on efficiency and rationality of a deposit’s development. Definition of disturbed zones at the open pit benches is an actual scientific and practical task in terms of supporting stability and functionality of such facilities. Research aim is to study geophysical signs of disturbance of hard rocks by data of nondestructive ground-penetrating radar (GPR) observation of the surrounding rock mass at the working open pit benches in order to estimate their geological structure and differentiate by disturbance degree. Methodology. Nowadays, GPR data is overwhelmingly interpreted based on comprehensive analysis of amplitude, frequency and phase characteristics of an electromagnetic signal and without an attribute analysis of the wave field. When using the structural approach, based on the analysis of the dynamic and kinematic characteristics of the wave field, to identify hard rock disturbance areas, it becomes possible to significantly increase the accuracy of their determination and localization according to the nondestructive subsurface GPR research. Results. Based on GPR measurements, the author has studied geophysical signs of disturbed rock zones identification at the open pit benches which consist in a quantitative estimation of change in reflection response amplitude characteristic, permittivity of a section and Q factor attribute. Conclusion. Using the established relationships with the proposed analysis of geophysical signs, the GPR study data can contribute to the adoption of differentiated and providing greater stability parameters of benches and mining operations.

Landslide stabilization experience in Urtui open pit mine

2021 ◽  
pp. 102-106
Author(s):  
O. A. Isyanov ◽  
◽  
D. I. Ilderov ◽  
V. I. Suprun ◽  
S. A. Radchenko ◽  
...  
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Geological Structure ◽  
Stability Control ◽  
Open Pit Mine ◽  
Open Pit ◽  
Open Pit Mining ◽  
Coal Seams ◽  
Mining Operations ◽  
Early Access

Instability of pit wall slopes is the most critical accident in open pit mining. The risk of damages to pit walls is proportional to the height of exposed surfaces and to the time of exposure. Among many factors governing pit wall stability, the major factor is geological structure and weakening zones in rock mass. Deformation processes are initiated in host rock mass of coal seams mostly because of undercutting of weak interlayers. Alongside with local undercutting, another cause of landslides is transition of coal mining from down-dip extraction to up-dip extraction. The sequence of mining and morphology of weak interlayers also have influence on initiation and evolution of deformations. The basic component of engineering solutions on pit wall stability control is optimization of mining sequence and methods of accessing working horizons in open pit mines. Large-scale deformation of Western and Southeastern pit walls in Urtui mine could be avoided using the optimized sequence of mining operations. For example, mining advance mostly along the curve of the Urtui centroclinal fold, with early access and destress of the eastern and, first of all, western wings of the fold could make it possible to evade from up-dip mining of coal seams and, as a consequence, to solve the major geomechanical problems in the open pit mine.

scholarly journals Planetary fracturing and lineaments revealed in the Kovdor magnetite–apatite ore deposit by open pit mining

2020 ◽  
pp. 30-34
Author(s):  
I. B. Agarkov ◽  
◽  
I. M. Ignatenko ◽  
V. A. Dunaev ◽  
I. S. Kryuchkov ◽  
...  
Keyword(s):  
Rock Mass ◽  
Hard Rock ◽  
Laser Scanner ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mining Operations ◽  
Structural Mapping ◽  
Remote Assessment ◽  
Tectonic Origin

The analysis of the studies into fracturing of Zhelezny pitwall rock mass over the period from 1989 to 2019 proves that planetary fracturing is represented by faults, carbonatite dykes and single fractures oriented in the same direction as the prevailing regional lineaments on the Kola Peninsula. Planetary fracturing is assumed as a system of regular-oriented fractures. The planetary fracturing also includes lineaments of tectonic origin. The scientists think the faults registered in the pitwall rock mass and codirectional with the lineaments will accompany mining operations down to the full depth of the pit, up to the full extraction of magnetite–apatite ore reserves. While preparing this article, the authors have collected, generalized and analyzed the data of geological and structural mapping implemented by VIOGEM’s experts over the period from 1989 to 2019. VIOGEM’s procedure of geological and structural mapping ensures continuous documentation of extensional tectonics at high referencing accuracy (to 50 cm), as well as determination of inaccessible azimuths and angles of fractures by remote assessment of their orientations in pit walls using a laser scanner and photographic techniques to study the structure of hard rock mass and the behavior of permanent benches.

scholarly journals On evaluation of complex-structured coal deposits based on their typical geometric features

2021 ◽  
Vol 303 ◽  
pp. 01029
Author(s):  
Alexander Katsubin ◽  
Victor Martyanov ◽  
Milan Grohol
Keyword(s):  
Surface Mining ◽  
Geological Structure ◽  
Point Of View ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mining Operations ◽  
Coal Deposits ◽  
Geological Conditions ◽  
Wide Range ◽  
Large Length

Information about the geological structure of Kuznetsky coal basin (Kuzbass) allows us to note that coal deposits developed by open-cast method are characterized by complicated conditions and have the following features: large length of deposits at significant depths of occurrence; coal series bedding of different thicknesses (from 1 to 40 m); different dip angles (from 3 to 90º); a significant number of dip and direction disturbances; different thickness of unconsolidated quaternary sediments (from 5 to 40 m); a wide range of strength values of rocks. In addition, there is a thickness irregularity and frequent variability of elements of occurrence of coal seams within the boundaries of a quarry field both in length and depth of mining. From the point of view of open-pit mining, such deposits are complex-structured. The factors listed above have a decisive influence on the choice of technical means, the order of development and the possibility of carrying out surface mining operations. Therefore, there is a need for a systematization of mining and geological conditions for the development of coal deposits, the purpose of which is to ensure a process of evaluation of complex-structured coal deposits for the development of coal-bearing zones by various complexes of equipment.

scholarly journals Study on failure law of rock mass and slope stability by open-pit combined mining

2021 ◽  
Vol 248 ◽  
pp. 03013
Author(s):  
Feng Shaojie ◽  
Gao Chen ◽  
Liu Wenbo
Keyword(s):  
Field Theory ◽  
Rock Mass ◽  
Slope Stability ◽  
Simulation Method ◽  
Geological Structure ◽  
Open Pit ◽  
Copper Mining ◽  
Failure Properties ◽  
Mining Methods ◽  
Reinforcement Measures

With the continuous downward mining, more and more attention has been paid to the problem of slope stability under open-pit combined mining. Taking Zijinshan gold and copper mining as an example, the failure properties of overlying rock mass and slope stability under open-pit combined mining under different mining methods are studied by numerical simulation method, and the failure law of overlying rock mass is proposed. Combined with the geological structure distribution of 5-5 section and the influence of different mining stages, the slope stability is evaluated by slip field theory. Relevant reinforcement measures are proposed.

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.

EVALUATING RELATIONSHIP OF SELF-BURNING OF BREEDS WITH DEFORMATION PROCESSES IN THE COMBINED DEVELOPMENT OF SUMMARY ORE DEPOSITS

2020 ◽  
Vol 2 (1) ◽  
pp. 329-341
Author(s):  
M.V. RYLNIKOVA ◽  
◽  
D.N. RADCHENKO ◽  
G.I. AYNBINDER ◽  
E.N. ESINA ◽  
...  
Keyword(s):  
Rock Mass ◽  
Spontaneous Combustion ◽  
Atmospheric Oxygen ◽  
Ventilation System ◽  
Ore Deposits ◽  
Open Pit ◽  
Environmental Damage ◽  
Mining Operations ◽  
Deformation Processes ◽  
Relationship Of

For decades and centuries, spontaneous combustion of minerals occurs, which leads to significant material, economic and environmental damage. Under anthropogenic impact on the subsoil, conditions are created for the active development and opening of cracks as a result of deformation of the rock mass, under the influence of its open and underground parttime work. as a result, the emergence of conditions for the active penetration of atmospheric oxygen from the mine ventilation system and the surface atmosphere along the cracks formed as a result of deformation to sulfur-containing minerals of ores and rocks, prone to oxidation and spontaneous combustion. The mechanism of spontaneous combustion of pyritic rocks in the rock mass during the development of deposits is analyzed. It is proved that in the combined development of pyrite ore deposits, exogenous physicochemical processes must be considered in conjunction with geomechanical processes due to the development of mining operations beyond the open pit contour, aerogasdynamic determined by the method, scheme and ventilation system of an underground mine, as well as thermo-physical processes occurring as a result of exothermic oxidation of sulfides...

scholarly journals The Challenges of Open-Pit Mining in the Vicinity of the Salt Dome (Bełchatów Lignite Deposit, Poland)

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1913
Author(s):  
Marek Cała ◽  
Katarzyna Cyran ◽  
Joanna Jakóbczyk ◽  
Michał Kowalski
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Salt Dome ◽  
Open Pit ◽  
Open Pit Mining ◽  
Stability Conditions ◽  
Mining Operations ◽  
Mass Behavior ◽  
Geological Conditions ◽  
Wall Slope

The extraction of the Bełchatów lignite deposit located in the vicinity of the Dębina salt dome requires careful planning that considers the influence of mining projects on the slope and salt dome stability conditions. The instability problem is directly related to horizontal and vertical displacement, as well as the complex geological and mining conditions. These conditions are very unique with regard to the co-occurrence of the salt dome and lignite deposits in the same area, as well as the large scale of the pit wall slope. Thus, predicting rock mass behavior and ensuring the safety of mining operations are important issues. The presented analysis focused on the influence of long-term lignite extraction on the western pit wall slope of the Bełchatów field and the salt dome’s stability conditions. This study offers a comprehensive approach to a complex geotechnical problem defined by large-scale, complex geometry, and geological conditions. The rock mass behavior and stress conditions are simulated in numerical modelling. The results of the presented analysis will be useful not only for present mining activities but also for future developments related to post-mining and recultivation plans.

scholarly journals Technological schemes of coal extraction in closed mines with the use of backhoes

2021 ◽  
Vol 303 ◽  
pp. 01059
Author(s):  
Vladimir Makarov ◽  
Valery Kolesnikov ◽  
Dawid Szurgacz
Keyword(s):  
Rock Mass ◽  
Characteristic Feature ◽  
Scientific Research ◽  
Coal Extraction ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mining Operations ◽  
Coal Deposits ◽  
Environmental Requirements ◽  
Coal Reserves

At the present time on the fields of operating and closed-down mines there are sections of open-pit operations. However, the adopted technology does not meet environmental requirements, there are no scientific recommendations on the technology of open-pit mining in hazardous areas of mine fields, there is no substantiation of the boundary contours of open-pit mining. A characteristic feature of depleted mine fields is the disturbed rock mass and the lack of concentrated coal reserves within their boundaries. In fact, coal reserves are represented in the form of fragmentary volumes of safety pillars and substandard reserves in places of geological disturbances. Limitation of mine fields in terms of various infrastructure objects imposes special requirements for mining operations. In these conditions it is not possible to apply the classic mining systems and technologies. This predetermines the necessity to develop new technological solutions. Therefore, scientific research on justification of technology for extraction of remaining reserves of coal after underground development of inclined and steep-sloping coal deposits with simultaneous reclamation of disturbed lands is actual.

scholarly journals The Study of Parameters of Quarry Faces in Muruntau and Myutenbai Open Pits in Case of Applying Major Blasts

2019 ◽  
Vol 4 (1) ◽  
pp. 4-15
Author(s):  
B. R. Raimzhanov ◽  
A. R. Khasanov ◽  
R. R. Vakhitov
Keyword(s):  
Rock Mass ◽  
Slope Angle ◽  
Field Measurements ◽  
Geological Structure ◽  
Open Pit ◽  
Open Pit Mining ◽  
Bench Height ◽  
Before And After ◽  
Hydraulic Excavators ◽  
Parameter Field

The paper presents process layouts for excavation of zones near pit envelope based on the analysis of findings of the ore loss study in case of open-pit mining, as well as the results of field measurements in the quarry faces in Muruntau and Myutenbai open pits. In the course of the field measurements, parameters of the quarry faces at Muruntau and Myutenbai open pits were determined under the following working conditions of an excavator: at full bench with shotpile height of 19–21 m; at full bench with shotpile height of 12–14 m at excavation of the “blast cap”; at heading face and taking ramp material. In all the above-listed quarry faces, the slope angles and the ore mass shotpile height when excavating were measured. Besides, the used excavator type (dragline or hydraulic) was taken into account. For each face, 2–3 measurements were performed, and the average slope angle at the ore mass excavation was determined for each type of excavator. At the next stage of the field measurements, the bench height in the rock mass and the shotpile parameters were measured before and after blasting operations under the following arrangements for preparing the rock mass for excavation: a) under normal conditions, when the ore mass blasting is performed for the selected face or relieving wall of the required thickness; b) in compression with a “blast cap” formation; c) in the marginal parts of the bench. Based on the results of the actual bench height and the blasted rock shotpile parameter field measurements, the following conclusions were drawn: a) the actual slope angles of the quarry faces were 49° when excavating the “blast cap” using dragline excavators, and 53° when excavating the ore mass at full bench regardless of the excavator type used; the slope angles of 49° for the dragline excavator and 53° for the hydraulic excavators were taken for further calculations; b) the width of the marginal (near-envelope) zone, where losses and dilution of balance ore are generated, increased from 7 to 13.0 m (at 49°) and from 7 to 11.3 m (at 53°); as a result, the areas of loss and dilution triangles have increased; c) when blasting in compression conditions, in the upper part of the shotpile, intense mixing of the involved rock and all ore grades occurs, therefore, when excavating the “blast cap”, bulk ore mass mining is only possible. The lower part of the blasted bench preserves the geological structure of the rock mass to a greater degree and can be selectively excavated with separation of the ore mass by grade; d) when blasting the rock mass, to maintain the required pulse direction and the blasting sequence, barren boreholes are included in the breaking outline, which increase the balance ore dilution, and structural dilution arises, which should be taken into account when drawing up the "Methods for determining, limitation and accounting for ore losses and dilution in the course of the Muruntau and Myutenbai (the fifth stage) open-pit mining"; e) when compiling the "Methods ...", the option of dividing a bench of 15 m high into two sub-benches of 7.5 m should be considered.

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