The paper presents results of conducted research using regional and local methods of forecast and control over geomechanical state of the rock mass at burst-hazardous Nikolayevskoye field, located in a geodynamically active region. The study subject is the ore mass of Nikolayevskoye field, characterized by man-induced and tectonic disturbances and high geodynamic activity. The aim of research was practical implementation of methods and instruments of forecast and control over geomechanical state of the burst-hazardous rock mass and safety improvement of mining operations. Exploitation practice of burst-hazardous fields demonstrates that forecast accuracy of hazardous rock pressure demands cutting-edge multi-level systems, where local methods and tools complement regional ones. A regional forecast of rock-burst hazard at Nikolayevskoye field was performed by means of seismoacoustic method using automated control system for rock pressure (ACSRP) «Prognoz-АDS». Local forecast was carried out using «Prognoz-L» device, geophysical (sample disking) method and visual observations of dynamic pressure manifestations in the mining tunnels. Quality assessment of stress-strain and burst state of the rock mass was performed using specialized software «PRESS 3D URAL». Integration of engineering and geomechanical data in the process of conducting research guarantees a relevant assessment of rock-burst hazard in various areas of the field at various stages of its development. Practical verification of the system, where local methods and tools complement regional ones, demonstrated satisfactory results at Nikolayevskoye mining plant, which makes it recommendable for other mining facilities extracting ore at great depths under similar conditions of active geodynamic processes.
The subject of the research is the stress-strain and rock burst hazardous state of the ore massif of the Nikolaevskoe polymetallic deposit, formed under the influence of complex mining-geological and mining-technical factors. The purpose of the research is to establish the peculiarities of the formation of technogenic stress fields at the deposit, which is characterized by a block structure, a complex tectonic system and the presence of a large volume of developed spaces. Volumetric geodynamic modeling of the stress-strain state of the massif at different stages of the development of the deep horizons of the deposit was carried out by collecting information on the structure, properties and geodynamic state of the rock mass. The assessment of stress changes taking into account the effect of hypsometry, the configuration of the selvages, the physical-mechanical properties of the ore deposit and host rocks, the presence of tectonic disturbances was made using the developed numerical algorithms, the automation equipment of the initial data and the PRESS 3D URAL software. The simulation made it possible to establish that tectonic faults in the massif lead to a qualitative change in the stress-strain state in certain parts of the ore massif and in the pillars, namely, the reduction of stresses along the tectonic faults and their growth in nearby pillars. The identified features of the distribution of stresses in the tectonically disturbed rock massif of the Nikolaevskoe deposit will allow to identify in advance potentially hazardous areas both at the planning stage of mining operations and during development, as well as to work out effective rock burst measures to increase the safety of mining. The results of research can be used in enterprises with similar mining-geological and mining-technical conditions.
The article describes practical experience of using room and pillar mining (RAPM) under conditions of deep horizons and dynamic overburden pressure. It was identified that methods of rock pressure control efficient at high horizons do not meet safety requirements when working at existing depths, that is explained by changes in geodynamic processes during mining. With deeper depth, the geodynamic processes become more intensive and number of pillar and roof failures increase. When working at 800 m the breakage of mine structures became massive and unpredictable, which paused a question of development and implementation of tools for compliance assessment of used elements of RAPM and mining, geological, technical and geodynamic conditions of North Ural bauxite deposits and further development of guidelines for safe mining under conditions of deep horizons and dynamic rock pressure. It describes reasons of mine structure failures in workings depending on natural and man-caused factors, determines possible hazards and objects of geomechanic support. It also includes compliance assessment of tools used for calculations of RAPM structures, forecast and measures for rock tectonic bursts at mines of OAO “Sevuralboksitruda” (SUBR). It describes modernization and development of new geomechanic support of RAPM considering natural and technogenic hazards. The article presents results of experimental testing of new parameters of RAPM construction elements of SUBR mines. It has data on industrial implementation of developed regulatory and guideline documents at these mines for identification of valid parameters of RAPM elements at deep depths.
The modern industrial corporations are deeply integrated which is expressed in a variety of connections and interactions. Key among these are technological connections based on which the commodity and cash flows are generated. The global innovative economy impacts economic activity integration and consolidation parameters, leading to organization of strategic management and value creation chains in mesoeconomic network structures with a single logistic center, intangible assets and a special system of long-term contracts. Product fabrication in the mineral resources sector is primarily associated with the large highly efficient companies. Meanwhile present competition in the global resource extraction and a need in further development and growth of the companies, especially in the resource-based economies, become a stimulus for implementation of large-scale strategic projects involving exploration of new mineral resources. As a rule, strategic projects in mineral sector have impact on the population and various business actors, on the development of an industry, a region and a country as a whole. Strategic investment projects in the mining sector are often implemented in complicated organizational, technical and economic setting, including poor infrastructure, harsh natural climatic and geographical conditions, lack of qualified staff, a need in large-scale funding, a need to mitigate material adverse effect on the environment. Large-scale projects implemented in the frontier regions have significant impact on the development of resource- based economies and cross-border cooperation. Selection of a modality for implementation of the mining project and assessment of its effects can be based on the added value concept, which maximizes the value growth. Value creation pattern depends on a number of production stages, depth of diversification, production capacity, company assets and range of products. Here it is important to consider not only project’s positive NPV, but also emerging additional effects related to project integration and implementation in the value chain. The purpose of the study is to justify a methodic approach based on the value chain to the assessment of effects of a large-scale mining project, which may have impact on a holding, a region, national economy and cross- border cooperation. The research carried out helped to justify the use of the added value concept for deciding on the type of pro ject for the field development, the basic and additional effects of a large-scale mining project have been revealed and possible organizational and economic framework for creation of tin industry in the Republic of Kazakhstan has been proposed.
The analitic method for calculating the parameters of the transmarginal deformation ore with the wide range of geological and mining- technical factors. Shows a graph of transmarginal deformation ore main varieties of bauxite ore from excavation size, depth and capacity of the ore deposit in the application for room-and -pillar system with compliant interchamber pillars on deep horizons of JSC «Sevuralboksitruda».
The design procedure parameters of system of pillars of when developing coal-bed dangerous on rockburst. Recommendations about a choice of parameters of pillars are provided for example the preparation of protective seams Fifth and Fourth on JSC «Vorkutaugol» mines.
Considered directions of geomechanical provide room-and-pillar system rock burst ore deposits at great depths, consisting in the modernization and development of the scientific basis of the complex methods for determining the allowable size of worked-out areas, the size of the roof chamber, the size a protective of the pillars, the size of the chamber – pillars, including with regard to their dynamic burst, and creating automated software system for long-term forecasting of the geodynamic state of the ore deposit and shockproof advance planning of activities to improve the safety of mining operations.
Examined the scientific and methodological provisions for the safe application of room-and-pillar system in complex geotechnical and geodynamic conditions due to advance the well processing zones bump hazard, the identification of which is achieved on the basis of long-term forecasting of the state of stress and bump hazard using automated software system «PRESS 3D URAL».
Positions of methodology of a complex estimation of influence of tectonic disturbances on stability of a rock mass for conditions of mining of ore deposits of a difficult geologic structure are considered. Degree of stability of a rock mass and constructive elements of mining methods in zones of influence of tectonic disturbances is estimated on size of an increment of stresses from action of motions on a contact surface of a tectonic disturbance.
Results of the analysis of factors of mining operations influencing safe conducting are resulted. Technological solutions on the pressure control, allowing messages mining operations on the big depths in rock-bump hazardous conditions are considered. Methodical positions and results of definition of parameters of constructive elements of systems of minings for conditions North Ural bauxite deposits are resulted.
The safe parameters of temporary interchamber pillars have been determined for the chamber-and-pillar method with ore discharge on trenches in designing of underground mining of the Koashva apatite-nepheline deposit. The results of calculation of economical efficiency of comparable parameters are presented. It was substantiated that the economical efficiency of application of the chamber-and-pillar method up to the depth of 800 m is related to the increase of natural yielding of interchamber pillars.
Comparison of results of calculations of the tangential stresses on the inner contour of tunnel lining and radial stresses on the outer contour is done. Stresses are found by solving the problem of interaction in geomechanical system «lining-ground massif» in 2D and 3D model (single layer tunnel lining and double layer tunnel lining). Area of correct application of 2D models are revealed.
The paper presents the results of a computer modeling technology applied in the «Sevuralboxitruda» enterprise. The aim of the technology is to forecast geodynamical processes during mining works in tectonic-stressed zones of ore deposits. The impact degree on structural components of room-and-pillar mining method caused by active tectonic faults is estimated.
The results of introduction at coal mines of the methods for determination of coal pillar sizes in preparation of rockburst-hazardous seams with paired workings are discussed in the paper. Safe values of advancing in drivage of development workings with formation of yielding have been established.