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 ◽  
...  

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

Author(s):  
A. A. Koyankin ◽  
V. M. Mitasov ◽  
I. Ya. Petuhova ◽  
T. A. Tshay

The stress-strain state of the prefabricated monolithic element depends on its gradual installation and loading. Regulatory documents of the Russian Federation indicate the need to calculate precast-monolithic structures for two stages of construction: before and after the specified monolithic concrete strength acquired. In this case, the stress-strain state that appeared in the prefabricated elements before the specified monolithic concrete strength should be considered.  However, the construction and loading stages at issue and accumulation of stresses and strains are not disclosed in the regulatory documents. In addition, this problem is insufficiently studied.  In this regard, the aim of this paper is to study the pre-loading effect of the prefabricated element on its stress-strain state and the load-bearing capacity.  During the experiments, a pre-loaded prefabricated part is studied. The obtained results are compared with instantaneously loaded test samples. Other parameters of the experimental models are completely identical. In all, 5 samples are tested (step-by-step loading of 3 samples and instantaneous loading of 2 samples).  It is shown that pre-loading of the preloaded prefabricated part significantly affects the stress-strain state of the whole structure and its total load-bearing capacity.  


Author(s):  
A.K Matayev ◽  
V.H Lozynskyi ◽  
A Musin ◽  
R.M Abdrashev ◽  
A.S Kuantay ◽  
...  

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.


Vestnik MGSU ◽  
2021 ◽  
pp. 463-472
Author(s):  
Zaven G. Ter-Martirosyan ◽  
Armen Z. Ter-Martirosyan ◽  
Ahmad Othman

Introduction. In case of brief exposure to static loads or dynamic loads, in conditions of absence of drainage, distribution of total stresses between the skeleton of soil and pore gas-containing water should be taken in account. The situation of the stress-strain state of the base is further complicated when we consider the degree of water-saturation of soil of the foundation (0.8 < Sr ≤ 1). The aim of the study is to pose and solve problem of the stress-strain state of a water-saturated soil massif, Including settlement and bearing capacity of a water-saturated base of a foundation of finite width, depending on the degree of water saturation of soils, taking into account the linear and nonlinear properties of the skeleton of soil and the compressibility of pore gas-containing water. Materials and methods. Henckyʼs system of physical equations are used as a calculation model to describe the relationship between deformation and stresses of soil, which takes into account the influence of the average stress on the deformation and strength properties of the soil. This system allows us to represent the linear deformation of the soil as the sum of the volumetric and shear components of the soil of this deformation. In addition allows us too to determine the deformation of the layer of soil, as part of the compressible thickness of the base of foundation with finite width under conditions of free deformations. Results. Depending on the linear and nonlinear deformation parameters, the settlement can be developed with a damped curve (S – p) and stabilize, and can be developed with a non-damped curve (S – p) and moved to the stage of progressive settlement. Conclusions. Solutions have been made for cases when the water-saturation of the base soils changes in the range of 0.8 to 1.0. It is shown that the settlement and bearing capacity of a water-saturated base significantly depends on the degree of water saturation of soils.


2020 ◽  
Vol 14 (2) ◽  
pp. 85-94
Author(s):  
Roman Dychkovskyi ◽  
Iaroslav Shavarskyi ◽  
Pavlo Saik ◽  
Vasyl Lozynskyi ◽  
Volodymyr Falshtynskyi ◽  
...  

Author(s):  
L.K. Miroshnikova ◽  
A.Yu. Mezentsev ◽  
G.A. Kadyralieva ◽  
M.A. Perepelkin

The Zhdanovskoe copper-nickel sulfide ores deposit is located in the north-west of the Murmansk region and is a mineral raw material source for JSC «Kola MMC». The main mining method used is sublevel caving. In some areas, due to the complex shape of the ore bodies, the open stoping mining method is used which requires determining stable parameters of stopes and pillars. It is necessary to study the stress-strain state of the deposit to ensure safe mining conditions. One of the possible solutions is the modeling of the stress-strain state of rock mass using the finite element method, for example, CAE Fidesys, which is FEMbased software. The use of CAE Fidesys for solving geomechanics tasks allows creating models of individual excavation units to determine the stability of stopes and pillars, and large-scale models that include several ore bodies and areas of the host rock mass. The article considers solutions of both types of geomechanic tasks using CAE Fidesys for conditions of the Zhdanovskoe deposit.


2019 ◽  
Vol 123 ◽  
pp. 01006 ◽  
Author(s):  
Iryna Kovalevska ◽  
Zenon Pilecki ◽  
Oleksandr Husiev ◽  
Vasyl Snihur

The degree of influence has been determined of diversified deformation-strength characteristics of load-bearing elements in the fastening system of the preparatory mine workings, while maintaining them in a laminal massif of soft rocks. The analysis has been performed of multivariate computational experiments of the stress-strain state of the load-bearing elements of the fastening system in the preparatory mine workings from the position of the mutual influence of their deformation-strength characteristics and the support loading as a whole. An analysis is represented of the mutual influence of the operation modes of the mine working support elements between themselves and the fastening system as a whole; it has been studied the stress-strain state of the mine working fastening system with a central hydraulic prop stay, as well as a significant increase in reliability of the support performance has been analysed and determined. The tendency has been substantiated of minimizing the load on the mine working fastening system – increasing the coherence of the diversified operation modes of fastening elements by enhancing preferentially the yielding property of the rigid element. The application has been substantiated of the central yielding prop stays of the strengthening support of a frame in case of intensive rock pressure manifestation in the zone of the stope works active influence.


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