scholarly journals Forecast changes in the geodynamic regime of geological environment during large-scale subsoil development

Author(s):  
M.B Nurpeisova ◽  
M.Zh Bitimbayev ◽  
K.B Rysbekov ◽  
Sh. Sh Bekbasarov

Purpose. Developing the methods for forecasting changes in the geological environment based on integrated monitoring, which ensures industrial and environmental safety of Central Kazakhstan region. Methodology. Integrated approach was used in the work, including: study on mining and geological conditions, structural features of rocks and conducting mine surveying at mines on the basis of modern methods and means of geomonitoring developed by the authors. Findings. Methodology for integrated geodynamic monitoring system is developed. A new method of geodynamic polygon establishment is proposed. Study results were implemented at operating mining enterprises during implementation of projects Comprehensive monitoring of slow deformation processes of the earths surface during large-scale development of ore deposits in Central Kazakhstan and Development of innovative methods for forecasting and assessing the state of rock mass to prevent technogenic emergencies, and the results were used in the educational process of Satbayev University. Originality. As a result of the research work carried out, the following were created and introduced into production: - geodynamic polygon (GDP) of the area, established on the basis of the nodal method, combined with leveling, satellite and seismological points, allowing monitoring coverage of exploration and mining operations, as well as increasing efficiency of observations and reducing capital costs for mineral production; - developed constructions of permanent (ground and underground) forced centering points (FCP), which allow increasing productivity and observations accuracy; - method for photographing structural features of rock mass using a 3D laser scanner, which makes it possible to study elements of cracks occurrence and faults in rocks in sufficient detail; - composition of strengthening solution from mining waste to increase stability of disturbed sections of open cast benches was developed. The novelty of the developed methods and means is confirmed by RK patents for invention. Practical value. Obtained results can be used to improve the level of industrial safety at mines and minimize environmental risks caused by subsoil development.

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1913
Author(s):  
Marek Cała ◽  
Katarzyna Cyran ◽  
Joanna Jakóbczyk ◽  
Michał Kowalski

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.


Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2818
Author(s):  
Yujun Xu ◽  
Liqiang Ma ◽  
Yihe Yu

To better protect the ecological environment during large scale underground coal mining operations in the northwest of China, the authors have proposed a water-conservation coal mining (WCCM) method. This case study demonstrated the successful application of WCCM in the Yu-Shen mining area. Firstly, by using the analytic hierarchy process (AHP), the influencing factors of WCCM were identified and the identification model with a multilevel structure was developed, to determine the weight of each influencing factor. Based on this, the five maps: overburden thickness contour, stratigraphic structure map, water-rich zoning map of aquifers, aquiclude thickness contour and coal seam thickness contour, were analyzed and determined. This formed the basis for studying WCCM in the mining area. Using the geological conditions of the Yu-Shen mining area, the features of caved zone, water conductive fractured zone (WCFZ) and protective zone were studied. The equations for calculating the height of the “three zones” were proposed. Considering the hydrogeological condition of Yu-Shen mining area, the criteria were put forward to evaluate the impact of coal mining on groundwater, which were then used to determine the distribution of different impact levels. Using strata control theory, the mechanism and applicability of WCCM methods, including height-restricted mining, (partial) backfill mining and narrow strip mining, together with the applicable zone of these methods, were analyzed and identified. Under the guidance of “two zoning” (zoning based on coal mining’s impact level on groundwater and zoning based on applicability of WCCM methods), the WCCM practice was carried out in Yu-Shen mining area. The research findings will provide theoretical and practical instruction for the WCCM in the northwest mining area of China, which is important to reduce the impact of mining on surface and groundwater.


2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Meng Wang ◽  
Jia-wen Zhou ◽  
An-chi Shi ◽  
Jin-qi Han ◽  
Hai-bo Li

The stability of the surrounding rock masses of underground powerhouses is always emphasized during the construction period. With the general trends toward large-scale, complex geological conditions and the rapid construction progress of underground powerhouses, deformation and failure issues of the surrounding rock mass can emerge, putting the safety of construction and operation in jeopardy and causing enormous economic loss. To solve these problems, an understanding of the origins and key affecting factors is required. Based on domestic large-scale underground powerhouse cases in the past two decades, key factors affecting the deformation and failure of the surrounding rock mass are summarized in this paper. Among these factors, the two most fundamental factors are the rock mass properties and in situ stress, which impart tremendous impacts on surrounding rock mass stability in a number of cases. Excavation is a prerequisite of surrounding rock mass failure and support that is classified as part of the construction process and plays a pivotal role in preventing and arresting deformation and failure. Additionally, the layout and structure of the powerhouse are consequential. The interrelation and interaction of these factors are discussed at the end of this paper. The results can hopefully advance the understanding of the deformation and failure of surrounding rock masses and provide a reference for design and construction with respect to hydroelectric underground powerhouses.


2020 ◽  
Vol 7 (7) ◽  
pp. 83-91
Author(s):  
Irina V. Abaturova ◽  
◽  
Ivan A. Savintsev ◽  
Liubov A. Storozhenko ◽  
Elvina D. Nugmanova ◽  
...  

geological environment. Actively change all the components of engineering-geological conditions (EGC), formed during the long geological time: the topography, structure of rocks, hydrogeological and permafrost conditions, are formed by geological processes and, at the same time on the surface of the Earth formed a new strata of man-made structures, and often man-made deposits. The scale of technogenesis in mining today is comparable to the results of geological activity that took place over many millions of years. Therefore, even at the early stages of studying the EGC MD, it is necessary to understand the dynamics of changes in the EGC in order to provide preliminary protective measures. Purpose of work. Consideration of striking examples of the dynamics of the EGC MD (from exploration to development), in order to provide methods for managing these changes. Methodology. The article considers the stages of obtaining engineering and geological information for the period of MD operation, which will solve the problems of rational use of the subsoil and protection of the geological environment. Results. For example, the number of objects marked all the stages of learning to yoke the dynamics of their changes, which led to the formation of engineering-geological processes that adversely affect the further testing of MD. Summary. The reaction of the geological environment in the development of MD is not long in coming and is expressed in the development of large-scale engineering and geological processes, which often do not allow further development of MD and threaten people's lives. Therefore, even at the early stages of studying the EGC MD, it is necessary to understand the dynamics of changes in the EGC in order to provide preliminary protective measures.


2019 ◽  
Vol 4 (1) ◽  
pp. 57-64
Author(s):  
R. I. Imranov ◽  
E. N. Khmyrova ◽  
O. G. Besimbayeva ◽  
S. P. Olenyuk ◽  
A. Z. Kapasova

The research is aimed at solving problems of assessing underground working stability in complicated mining and geological conditions to increase reliability and safety of mining operations. Analysis of geomechanical processes occurring in a rock mass during extraction of coal seams to determine the stability of mining block roof is the most important task. The performed digital modeling of the rock mass based on the structural logs for K1 seam and the nearest borehole log enabled highly detailed identifying the types of rocks occurred in the seam roof and their strength characteristics, compressive stresses. To determine the stability of a mining block roof, the factor of safety of the rocks was used, which was determined by modeling method using Phase 28.0 and Rockscince software. The carbonaceous argillite parting 0.09–0.12 m thick was taken as the contact of the longwall with the seam roof, and, for completeness of the analysis, the upper high-ash coal member in the seam roof up to 0.7 m thick was used. The modeling findings, presented in the graph of dependence between the safety factor and the distance between the belt heading and air drift, showed that the probability of dome formation in the longwall is high, as the factor of safety of the rocks is less than unity, that indicates the roof instability in the course of the coal seam block extraction. The modeling methods allowed assessing the mine working stability, based on which the measures to improve the reliability and safety of mining operations can be timely developed, and due technical and technological solutions shall be reached.


2021 ◽  
pp. 102-106
Author(s):  
O. A. Isyanov ◽  
◽  
D. I. Ilderov ◽  
V. I. Suprun ◽  
S. A. Radchenko ◽  
...  

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.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
C.W. Zang ◽  
G.C. Zhang ◽  
G.Z. Tao ◽  
H.M. Zhu ◽  
Y. Li ◽  
...  

This study was aimed at the large deformation phenomenon of rock mass surrounding the gob-side entry driven in a 20 m extra-thick coal seam. Taking tailgate 8211 as the engineering background, a numerical investigation was employed to analyze the deformation law of the gob-side entry. The study results are as follows. (1) Because the immediate roof was composed of weak coal mass with a thickness of 17 m, the roof coal mass was vulnerable to fail with the effect of overlying strata pressure; thus, a visual subsidence of roof coal mass with a maximum convergence of 800 mm was observed in the field. (2) The bearing capacity of the coal pillar was significantly less than that of the panel rib, resulting in the pillar failing more easily under the ground pressure and then generating large-scale squeezing deformation. (3) The roof and panel rib were in a state of shear failure with a failure depth of about 5 m. The coal pillar was entirely in a state of plastic failure. (4) A support scheme including an asymmetric anchor beam truss, roof angle anchor cable, and anchor cable combination structure was proposed. The field work confirmed that this support scheme could efficiently control the deformation and failure of the rock mass surrounding the gob-side entry. This study provides the theoretical basis and technical support for the control of rocks surrounding the gob-side entry in similar conditions.


2021 ◽  
Vol 2076 (1) ◽  
pp. 012075
Author(s):  
Huifeng Zheng ◽  
Shuo Zheng ◽  
Yi Chen ◽  
Guanye Wu ◽  
Yong Zhou

Abstract During the construction of large-scale hydropower projects in deep mountain gorge areas of the Western China, the difficulties, such as uncontrollable large deformation, great deformation caused by small disturbance, are often encountered in the process of implementation. In particular, due to the limitation of topography, geological conditions and the layout of structures, the slope and dense tunnel group with large section need to be excavated simultaneously in the toppling rock mass. The feedback action mechanism between slope and tunnel excavation is complicated and the deformation control of toppling rock is difficult, which leads to great challenges to engineering construction. In MW hydropower project in west of China, the intake slope, the spillway channel slope, four headrace tunnels, and the sand flushing tunnel, as well as the construction traffic tunnel are arranged in Huishi Ridge on the left bank, where two high slopes and six lager cross-section tunnels are simultaneously excavated and the excavation rate in the toppling deformation rock mass is over 50%, moreover, the lateral coverage thickness of tunnel body is less than the diameter of the tunnel, which leads to the great difficulty of stability control. The excavation stability and safe of the thin mountain ridge is the vital issue to the success of the whole project. Based on the study of the physical and mechanical parameters of toppling rock mass of MW HPP, the mutual feedback mechanism of toppling slope and tunnel group is revealed, an excavation method involving horizontal partitioning, vertical layering, reserving rock plug and reasonable skipping warehouse is proposed. Monitoring results shows that the slope and surrounding rock of the tunnels are stable during the operation period. The research of this paper based on the MW HPP can provide reference for other similar projects.


2021 ◽  
Vol 304 ◽  
pp. 02002
Author(s):  
Vokhid Kadirov ◽  
Sherzod Karimov ◽  
Uchqun Qushshayev ◽  
Durdona Sharapova

The article presents a study and analysis of the causes of deformation of the slopes and sides of the quarry indicates that the magnitude and nature of the deformation processes depend on the height of the ledge, the angle of slope of the slopes, the physical and mechanical properties, the lithological and structural features of the instrument array and the geodynamic activity of the fault zones. The influence of the deformation zones of the sides of the quarry on the transport of rock masses is justified. The zone of deformed masses of the ore deposit, which affect the movement of the rock mass, is studied. Each process performed in open pit mining is linked to another workflow. Without ensuring the safety of mining operations and performing the tasks set is impossible. Transportation of rock masses in the lower horizons of a deep quarry is one of the main tasks of the industry. At the same time, the removal of deformation and landslides in the area where the transport berm is being constructed for draining and continuous transportation is the main goal of the quarry. The stability of the transport berm depends directly on the stability of the side of the quarry. It is determined that the choice of a single-lane or twolane transport berm constructed for heavy-duty quarry dump trucks depends on the condition of the side of the quarry.


Author(s):  
Timur Sh. Dalatkazin ◽  
◽  
Alfiia N. Kaiumova ◽  

Introduction. Complex hydrogeological conditions of the rock mass at Sokolovsky deposit are the cause of constant search for new solutions for industrial safety improvement. At the present time there is much information on engineering and geological conditions of the field rock mass which is a source of measures developed to ensure industrial safety and technological solutions in mining. Research aim. With the purpose of determining a tactics of mining security support, the information on the hydrogeological and engineering-geological conditions of Sokolovsky field was analyzed. Methodology. The article provides the details of Sokolovsky field structure. The factors have been revealed which are hazardous for mining: undrained hydrogeological horizons and complexes, karst, thixotropic rock within the open pit. These factors create the conditions for sludge and water accumulation and rush into the underground mine. The majority of sandshale rushes fall upon the main production horizons into the intake and transportation mine workings. Results. Directions have been determined for further investigation of the mechanism of hazardous phenomena development and realization in geological environment of the field; the investigation is directed at improving catastrophe prevention measures and personnel security measures. Summary. Currently, at the stage of field development, there emerged a need to study particular hydrogeological and geomechanical conditions in details in order to increase of effectiveness of drainage at local sites of the mass which are designed for ore extraction.


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