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Date submitted2020-05-08
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Date accepted2020-06-12
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Date published2020-12-29
Gas-dynamic roof fall during the potash deposits development
In the development of practically all potash salt deposits, the study of gas-dynamic phenomena (GDP) is one of the most difficult tasks to ensure mining safety. Sudden salt and gas outbursts, dynamic breakdown, which are accompanied by intense gas release and possible broken rock carry-over into the mine workings, are associated with GDP. Geological preconditions for the GDP development are often the layered structure of the salt rock mass, the presence of interlayers and layers of salt clays. For the conditions of the Usolsky potash plant mine, complex studies of factors that characterize the possibility of gas-dynamic roof fall of the stoping rooms were carried out. In mine studies, free gases pressure and the initial velocity of gas release in the rocks of the roof workings were determined. The obtained experimental estimations were used as a parametric basis for mathematical modeling of geomechanical processes under conditions of a near-contact accumulation of free gas. The deformation of a layered salt mass produced by a room development system was described by the model of an ideal elastic-plastic medium with internal friction. The parabolic envelope of Mohr circles was used as a plasticity criterion in the compression area. In the numerical implementation, the deformation of clay contacts was modeled by Goodman contact elements. Based on the results of multivariate numerical calculations, it is established that the main factors determining the possibility of implementing GDP are the additional gas pressure at the contact, the width of the workingspan, and the distance from the roof to the first gas-containing contact. With multi-level lamination of roof rocks, there is a danger of large sources of GDP formation and the mechanism of successive fall of layers in an instant mode is implemented.
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Date submitted2015-10-18
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Date accepted2015-12-01
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Date published2016-08-22
Effect of surface geometry and insolation on temperature profile of green roof in Saint-Petersburg environment
- Authors:
- S. A. Ignatev
- D. S. Kessel
The paper addresses an issue of creating an environment favorable for the life in megacities by planting vegetation on the rooftops. It also provides information about rooftop greening practices adopted in other countries. The issues of ‘green roof’ building in climatic conditions of Saint Petersburg and roof vegetation impact on the urban ecosystem are examined. Vegetation composition quality- and quantity-wise has been proposed for the roof under research and a 3D model of this roof reflecting its geometric properties has been developed. A structure of roof covering and substrate qualitative composition is presented. An effect of rooftop geometry on the substrate temperature is explored. The annual substrate temperature and moisture content in different parts of the roof have been analyzed. Results of thermal imaging monitoring and insolation modelling for different parts of green roof surface are presented.
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Date submitted2013-07-16
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Date accepted2013-09-16
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Date published2014-03-17
Stopes walls stabilization at the rich iron ore mining by the flat-back cut-and-fill method
- Authors:
- V. P. Zubov
- M. D. Morozov
- A. S. Malyutin
The most influencing the stopes walls stability factors have been determined. Physical-and-mechanical ore mass properties impact to the stopes height has been researched. Advanced ways to improve stopes walls stability have been considered.
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Date submitted2013-07-16
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Date accepted2013-09-20
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Date published2014-03-17
Choice and valuation of similarity parameters for aero-gas-dynamic modeling with main roof collapse
- Authors:
- V. V. Smirnyakov
The article describes the necessary conditions for similarity parameters choosing for aero-gas-dynamic modeling with main roof collapse and it has been made analysis of them.
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Date submitted2013-07-02
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Date accepted2013-09-01
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Date published2014-03-17
Analytical estimation of aerodynamic characteristics of the main roof collapse
- Authors:
- V. V. Smirnyakov
The article describes the formulas for calculation of air flow characteristics, that originates from the main roof collapse and also it has been made analysis of variates, that form their parts.
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Date submitted2009-10-28
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Date accepted2009-12-25
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Date published2010-09-22
Prediction of dynamic manifestations of rock pressure in the all over automated longwalls
- Authors:
- M. Roiter
- V. Kurfyurst
- K. Mairkhofer
- J. Veksler
The support control system «MARCO» has programs for the estimation of a geomechanical situation around the face by continuous measurements of pressure in the legs of support. The analysis of the face convergence allows to predict the possibility of a rock burst. The seam’s reaction on the shearer or plough influence may be the dangerous main roof collapse into the mine-out space of longwall.
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Date submitted2009-10-30
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Date accepted2009-12-09
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Date published2010-09-22
Investigation of regularities of rock inrush forming in productive faces of сoal mines
- Authors:
- Yu. M. Khalimendik
- A. V. Brui
- M. V. Chemakina
The aspect of maintenance of roof stability of active stopes in mines of the Western Donbass is considered in the article. The conclusion is drawn on the probability of coal falls formation during mining operations in disturbed areas. Principal causes of coal fall formation are considered on the bais of natural surveying observations. Connections between technological parameters of longwall and geometrical parameters of disturbance are established.
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Date submitted2009-07-22
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Date accepted2009-09-18
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Date published2010-04-22
Higher grade filling due to horizontal layers extraction in Yakovlevsky ore deposit
A complex of technology and organization methods to higher grade filling due to horizontal layers system of extraction rich ferrous metal ores for various stages of mining is presented.
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Date submitted2009-07-29
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Date accepted2009-09-15
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Date published2010-04-22
Preconditions for application of supports of different types in productive workings of low-thick gently-pitching deposits in tectonically stressed massif (for conditions of the Karnasurt ore mine)
- Authors:
- A. V. Lovchikov
- A. V. Matytsyn
The paper presents the data on the mining-geological conditions for mining and types of stope supports applied at the Karnasurt Mine, the Lovozersky rare-metal deposit. The peculiar feature of mining conditions is the presence of high subhorizontal tectonic stresses in the rock masses, which make the stope roofs more stable, allowing application of non-reinforced types of support.
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Date submitted2009-07-05
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Date accepted2009-09-25
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Date published2010-04-22
Active methods for control of geomechanical state of rock mass in coal deposit mining under complicated geological-and-mining conditions
- Authors:
- F. N. Voskoboev
- Yu. A. Semenov
- V. A. Zvezdkin
The paper presents the main technologies, characteristics, schematic diagrams and parameters of active methods for control of geomechanical state of technogenic rock mass, domain and technical-and-economical efficiency of their industrial application.