Application of Numerical and Block Geomechanical Modelling to Determine Parameters of Large-Section Chambers

2021 ◽  
pp. 127-131
Author(s):  
M.A. Sonnov ◽  
A.V. Trofimov ◽  
A.E. Rumyantsev ◽  
S.V. Shpilev
Keyword(s):  
Rock Mass ◽  
Strain State ◽  
Stress And Strain ◽  
Underground Structures ◽  
Geomechanical Model ◽  
Principal Stresses ◽  
Mine Support ◽  
History Of ◽  
Crushing Plant ◽  
Ore Pass

The study is exemplified by complex workings of a main ore pass that include a variety of underground structures, usually with unique dimensions which depend on the function and size of the equipment placed. The technical solutions for the underground crushing plant and associated structures envisage construction of chambers with the height of up to 35 m and the width of up to 20 m at the depths exceeding 800-1000 m. Such conditions call for a closer attention to be paid to the mine support parameters, especially the bolting depth. A block geomechanical model was designed in the Micromine Mining Software for the rock mass of the new main ore pass. Geotechnical boreholes logs and results of physical and mechanical rock tests were used as the input data for the model. Four domains were identified in the block geomechanical model for subsequent numerical modelling. A 3D model of the stress-and-strain state of the rock mass was made using the CAE Fidesys software based on the Micromine wire-frame model of the main ore pass. The history of the rock mass incremental loading was reconstructed for correct simulation of its stress-and-strain state. Prior to the excavation, the rock mass is pre-stressed by the weight of the rock strata. The excavation phase was then simulated in the stepwise manner. An array of points with the values of maximum principal stresses was downloaded from the numerical model post-processing program and interpolated into the block geomechanical model to refine the SRF parameter of the Barton's Q rating. Based on the obtained Q values, the mine support parameters for chambers were determined using the Barton, Hutchinson and Potvin empirical methods.

scholarly journals Analytical analysis of the stress-strain state of the system “mechanized equipment complex - support – rock mass” in the bottomhole area of the shaft

2018 ◽  
Vol 193 ◽  
pp. 02026 ◽  
Author(s):  
Alexander Pankratenko ◽  
Mikhail Pleshko ◽  
Alexander Isaev
Keyword(s):  
Rock Mass ◽  
Strain State ◽  
Payback Period ◽  
System Support ◽  
Capital Investments ◽  
Underground Structures ◽  
System Operation ◽  
Technological Factors ◽  
Geotechnical System ◽  
Planar Contact

The development of new deposits requires the construction of deep and super deep vertical shafts. The duration of their construction reaches 8 - 10 years with multi-billion capital investments. To reduce the payback period of these costs, it is necessary to develop and implement effective solutions to increase the speed of sinking operations through the wide introduction of brand-new mechanized equipment complexes. In response to the sinking in the bottomhole area of the shaft, the following geotechnical system is being formed: “tunnelling system - support - rock mass”, the regularities of which require further study. For these purposes, an analytical method for calculating the shaft support can be used in the context of consideration of a planar contact problem at various phases of the system operation. The mutual coordination of individual phases in accordance with the classical concepts of the underground structures mechanics is possible using a correction factor to the magnitude of horizontal stresses in the rock mass. In this paper, we developed the algorithm which determines this coefficient, taking into account the influence of the main technological factors: the pressure of the jack system of the complex and the speed of sinking.

scholarly journals Mathematical modeling of tight roof periodical falling

2018 ◽  
Vol 60 ◽  
pp. 00020 ◽  
Author(s):  
Vira Prykhodko ◽  
Nataliia Ulanova ◽  
Oleksandr Haidai ◽  
Dina Klymenko
Keyword(s):  
Mathematical Modeling ◽  
Rock Mass ◽  
Boundary Element Method ◽  
Coal Seam ◽  
Mine Working ◽  
Strain State ◽  
Stress And Strain ◽  
Mine Workings ◽  
Roof Falling ◽  
Enclosing Rocks

The paper proposes a method to determine of a coal seam roof falling step basing upon the analysis of stress and strain state of the rock mass area with mine workings formed as a result of coal preparatory and extraction operations. A boundary element method has been applied to define stress and strain state (SSS). Fissuring of enclosing rocks was modeled by means of transversal-isotropic medium. Dependence of destructed rocks zone height within the roof of a seam being mined upon the weakening of the rock mass due to its fissuring and mine working geometry has been determined. Effect of fissility on the periodical roof falling step has been studied. Changes in support loads in the process of stope advance have been determined. A scheme of partial backfilling of the worked out area has been proposed to maintain the support in its working order.

Specific Features of Calculating Underground Structures Erected with Use of Freezing Method

2015 ◽  
Vol 725-726 ◽  
pp. 179-184
Author(s):  
Igor Sakharov ◽  
Vladimir Paramonov
Keyword(s):  
Finite Elements ◽  
Strain State ◽  
Full Scale ◽  
Finite Elements Method ◽  
Stress And Strain ◽  
Underground Structures ◽  
Saint Petersburg ◽  
Freezing Method ◽  
Subway Stations ◽  
Water Saturated

The article regards the problems arising in building the underground structures and, in particular, escalator tunnels under the built-up areas. In case of a thick mass of weak water-saturated soil such tunnels are frequently made with the use of freezing method. The purpose of this article consists in evaluating influence of the established and degrading ice structures on soils deformations and objects contacting with them. It is offered to assess this influence using the finite elements method contemplating a consecutive solution of temperature tasks and the tasks of stress and strain state of soil in time in 3D erection. The article describes briefly the formula part and specific features of calculating temperatures and deformations of soils. By way of example a calculation of defrosting deformations around an inclined tunnel for one of the deep-laid subway stations in Saint-Petersburg has been made. The data of performed calculation are closely approximated to the full-scale measurements.

scholarly journals Research into rock mass geomechanical situation in the zone of stope operations influence at the 10th Anniversary of Kazakhstan’s Independence mine

2021 ◽  
Vol 15 (1) ◽  
pp. 103-111
Author(s):  
Azamat Matayev ◽  
Ainash Kainazarova ◽  
Ibatolla Arystan ◽  
Yerkebulan Abeuov ◽  
Arman Kainazarov ◽  
...  
Keyword(s):  
Rock Mass ◽  
Bearing Capacity ◽  
Strain State ◽  
Stability Margin ◽  
Principal Stresses ◽  
Stress Strain ◽  
Load Bearing Capacity ◽  
10Th Anniversary ◽  
Stress Strain State ◽  
Mine Workings

Purpose. Predicting the stress-strain state (SSS) of the rock mass in the zone of stope operations influence using the self-caving mining system and the calculation of the load-bearing capacity of mine workings support at the 10th Anniversary of Kazakhstan’s Independence mine. Methods. An engineering-geological data complex of the host rocks properties has been analyzed. Numerical modelling of the rock mass stress-strain state and the calculation of the load-bearing capacity of the support types used at the mine have been performed with the help of the RS2 software. This program, based on the Finite Element Method in a two-dimensional formulation, makes it possible to take into account a significant number of factors influencing the mass state. The Hoek-Brown model with its distinctive advantage of nonlinearity is used as a model for the mass behaviour. Findings. The values of the main stresses and load on the support have been obtained. According to the numerical analysis results of the rock mass stress-strain state at a depth of 900 m (horizon -480 m), the principal stresses are close to hydrosta-tic ones σ1 = σ2 = σz = 24.8 MPa. Predicting assessment of mine workings stability margin is performed before and after stope operations. Based on its results, it can be assumed that the stability margin of the mine workings driven in the stope zone is below the minimum permissible, therefore, caving and an increase in the load on the support are possible. Abutment pressure on mine workings support at a mining depth of 900 m (-480 m) has been calculated. The parameters of support in mine workings driven at the horizon -480 m have been calculated. Originality.The nature and peculiarities of patterns of the stress-strain state formation within the boundaries of various stope operations influence in blocks 20-28 at the horizon -480 m have been determined. The quantitative assessment of the values of loads on the support of haulage cross-cuts of the horizon mining is given. Practical implications. The research results can be used for creating a geomechanical model of the field and to design stable parameters of mine workings support. Keywords: stress-strain state, principal stresses, support, mine, ore, rock mass

Integrated Evaluation of the Worked-Out Area Partial Backfill Effect of Stress-Strain State of Coal-Bearing Rock Mass

2018 ◽  
Vol 277 ◽  
pp. 213-220 ◽  
Author(s):  
Dmytro Malashkevych ◽  
Vadym Sotskov ◽  
Volodymyr Medyanyk ◽  
Dmytro Prykhodchenko
Keyword(s):  
Rock Mass ◽  
Strain State ◽  
Coal Seams ◽  
Geomechanical Model ◽  
Stress Strain ◽  
Stress Strain State ◽  
Stress Components ◽  
Selective Mining ◽  
Mass Displacement ◽  
Pressure Stress

The paper gives information on the engineering solution concerning the extraction of thin coal seams with partial backfill of the worked-out area. Geomechanical model of coal-bearing rock mass has been substantiated. A technique to carry out computational experiment aimed at the processes of coal-bearing rock mass displacement within a zone of extraction influence has been represented. Curves of rock pressure stress components distribution (i.e. horizontal stresses, vertical stresses, and stress intensity) within the front bearing pressure and worked-out area for traditional methods (if roof is controlled by means of complete rockfall) and for selective mining with partial backfill have been plotted. Relying upon the carried out studies of stress-strain state of coal-bearing rock mass, overall conclusion has been made on the advantage of selective mining with partial backfill from the viewpoint of geomechanics of the rock mass behaviour.

scholarly journals Monitoring of the stress-strain state of open pits’ adjacent rock mass

2020 ◽  
Vol 192 ◽  
pp. 04017
Author(s):  
Andrey Panzhin ◽  
Natalia Panzhina
Keyword(s):  
Rock Mass ◽  
Strain State ◽  
Industrial Site ◽  
Deformation Characteristics ◽  
Geomechanical Model ◽  
Stress Strain ◽  
Time Periods ◽  
Mine Surveying ◽  
Negative Factors ◽  
Adjacent Rock

In the course of the work to identify the modern coordinates of the points of the state (SGN) and reference mine surveying (RMSN) networks of Orenburg Minerals JSC, the deformation characteristics of the earth’s surface in different time periods were obtained and a geomechanical model of the rock mass was built both on the industrial site itself (quarry, dump), and beyond the areas, influenced by mining. Based on the data obtained, the parameters of deformation of the rock mass and the adjacent rock mass in three planes, as well as the relative deformations and the magnitudes of the tectonic stresses that caused them were identified; during the analysis of negative factors potentially dangerous areas of the adjacent rock mass were also identified.

scholarly journals Substantiating the optimal type of mine working fastening based on mathematical modeling of the stress condition of underground structures

2021 ◽  
pp. 57-63
Author(s):  
A.K Matayev ◽  
V.H Lozynskyi ◽  
A Musin ◽  
R.M Abdrashev ◽  
A.S Kuantay ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Rock Mass ◽  
Mine Working ◽  
Strain State ◽  
Processing Plant ◽  
Underground Structures ◽  
Stress Strain ◽  
Initial Stress Field ◽  
Stress Strain State ◽  
Mine Workings

Purpose. Predicting the formation of a stress-strain state (SSS) in the rock mass within the boundaries of influence of stope operations on the horizon -480 m in axes 2028 at the 10th Anniversary of Kazakhstans Independence (DNK) Mine. Methodology. An engineering-geological data on the host rocks properties are analyzed based on the international ISRM standard. Numerical modelling of the rock mass stress-strain state and the calculation of the load-bearing capacity of the compound support (roof-bolt+shotcrete+mesh) and arch support used at the mine are performed with the help of the RS2 software. This program, based on the Finite Element Method in a two-dimensional formulation, makes it possible to take into account a significant number of factors influencing the rock mass state. Findings. The calculations performed indicate that the support resistance is incommensurably low in comparison with the values of the initial stress field components in the rock mass. In such conditions, it may be more effective to strengthen the mass in the vicinity of mine working than setting more frames or using more massive support profiles. Originality. The paper presents the results of mathematical modeling and calculation of the stress-strain state of the underground supporting aquifer rock mass structures developed for complex mining-and-geological and geomechanical conditions of driving, supporting and operating mine workings on deep horizons of the mines at Donskoy Ore Mining and Processing Plant. Based on the performed research, the preliminary (advanced) strengthening of the border rock mass in the zone of inelastic (destructive) deformations has been substantiated, as a priority method to control the stability of mine workings. Practical value. The research results can be used when creating a geomechanical model of the field and designing stable parameters of mine working support.

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