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Date submitted2019-03-11
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Date accepted2019-05-06
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Date published2019-08-23
Estimation Method for Vector Field Divergence of Earth Crust Deformations in the Process of Mineral Deposits Development
- Authors:
- B. T. Mazurov
- M. G. Mustafin
- A. A. Panzhin
An essential requirement for effective and safe deposit development is good geomechanical software. Nowadays software packages based on finite element method are used extensively to estimate stress-strain state of the rock mass. Their quality use can only be assured if boundary conditions and integral mechanical properties of the rock mass are known. In mining engineering this objective has always been achieved by means of experimental observations. The main source of information on initial and man-induced stress-strain state of the rock mass is natural measurement of displacement characteristics. Measurement of geodetic data (coordinates, heights, directions) in the period between alteration cycles allows to plot a field of displacement vectors for the points in question. Taken together, displacement vectors provide information on the objective stress-strain state of the Earth crust. Basing on it, strain tensors, displacement components, directions and rates of compression and tension can be calculated in the examined area. However, differential characteristics of any physical vector field – namely, curl and divergence – need to be taken into account. Divergence is a single value (scalar) associated with a single point. Vector field as a whole can be described with divergence scalar field. Divergence indicates the sign (positive or negative) of volume changes in the infinitesimal region of space and characterizes vector flux in the nearest proximity and in all directions from a given point. In the paper authors propose a method to estimate divergence using discrete geodetic observations of displacement occurring on the surface of examined territory. It requires construction of formulas that model vector field for any point of the area. It is proposed to use power polynomials that describe displacement in three directions (x, y, z). These formulas allow to estimate field vectors in any given point, i.e. to form vector tubes. Then areas of input and output cross-section, as well as divergence values are calculated. This increases the quality of geodetic observation and provides opportunities for more precise modeling of the rock mass disrupted by mining operations, using modern software packages.
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Date submitted2018-07-21
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Date accepted2018-09-14
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Date published2018-12-21
Natural ventilation of gas space in reservoir with internal floating roof
- Authors:
- M. G. Karavaichenko
- N. M. Fathiev
The article deals with safe operation issues of vertical steel reservoirs with an internal floating roof when storing volatile oil products. The purpose of the work is to study the influence of ventilation openings area and wind speed on the duration of explosive state of vertical reservoirs with an internal floating roof. The influence of ventilation pipes' dimensions and the wind speed on the duration of explosive state of the reservoir has been studied. Method for calculating this time is proposed. It is shown that natural ventilation of the reservoir gas space is caused by the effect of two forces, which are formed due to: 1) the density difference between the vapor-air mixture in the reservoir and outside air; 2) wind pressure occurring on the roof of the reservoir. An algorithm for calculating the duration of reservoir being in an explosive state with wind pressure and no wind is obtained. The greater the difference in geodetic marks of the central and peripheral nozzles, the more efficient the ventilation. This distance will be greatest if the lower ventilation pipes are located on the upper belt of the reservoir or the reservoir is equipped with an air drain. Increase in wind speed of more than 10 m/s does not significantly affect the duration of the reservoir being in an explosive state. Increasing the diameter of the central nozzle from 200 to 500 mm can significantly reduce the duration of the reservoir degassing in windless weather.
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Date submitted2010-07-21
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Date accepted2010-09-08
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Date published2011-03-21
Calculation methodology of physical parameters of the artificial pillar barrier
- Authors:
- M. N. Adreev
The article is devoted to the calculation methodology of physical parameters of the artificial barrier pillar needed when developing underquarry deposits of kimberlitic pipes in difficult hydrogeological conditions.
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Date submitted2010-07-15
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Date accepted2010-09-26
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Date published2011-03-21
Development of the stowing material and testing of its mechanical properties
- Authors:
- M. N. Andreev
- E. I. Boguslavskiy
Article is in touch with analysis of backfill materials applied on diamond mines, description of research of its mechanical properties to create the optimal compound in conditions of Yakutian kimberlitic tubes.
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Date submitted2008-10-21
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Date accepted2008-12-10
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Date published2009-12-11
Prediction and prospecting types of reflection of buried kimberlite fields in terrigenous diamond-bearing rocks
- Authors:
- V. N. Ustinov
On the basis of complex of lithologic-stratigraphic, mineralogical, facial-dynamic, paleogeomorphologic and morphogenetic features of post-kimberlitic terrigenous diamond-bearing rocks and reconstructed synchronous relief three prediction and prospecting types of reflection of buried kimberlite fields are distinguished. It is shown that ranging of diamondiferous territories to various types enables to direct exploration works to discovery of diamond deposits of the certain origin and makes possible to select proper prospecting technique. With the use of suggested criteria of research of promising territories the evaluation of diamond presence in the industrial regions of the Siberian, East-European and African-Arabian platforms is carried out.