-
Date submitted2024-05-11
-
Date accepted2025-01-28
-
Date published2025-03-21
Research and development of technology for the construction of snow airfields for accommodating wheeled aircraft in Antarctica
- Authors:
- Sergey P. Polyakov
- Sergey V. Popov
Construction of a new wintering complex at the Antarctic Vostok Station required prompt delivery of builders and mechanics to Progress Station to move them further to the work area. To solve this major logistical issue, a new landing site, later named Zenit, certified for accommodating heavy wheeled aircraft, was prepared in the Progress Station area from March to August 2022. Its snow pavement slab with a total area of 350 thousand m2 is from 100 to 120 cm high. It was made by applying snow layers with their subsequent compaction by a specially designed compaction platform for snow airfields suitable for heavy wheeled aircraft. As a result, the pavement has a surface hardness of at least 1 MPa. The layer from 30 to 60 cm has a hardness of at least 0.8 MPa, and the bottom layer at least 0.6 MPa. The first Il-76TD-90VD aircraft of the Russian company Volga-Dnepr was accommodated to the new runway on 7 November 2022. The aircraft landed in normal mode. The depth of the chassis wheels track after landing did not exceed 3 cm. The research provided in-depth understanding of the mechanisms for forming the supporting base of the runway from snow and ice in Antarctica. The experience gained can be used to solve similar issues in the Far North.
-
Date submitted2022-08-10
-
Date accepted2023-02-28
-
Date published2024-02-29
Selection of the required number of circulating subs in a special assembly and investigation of their performance during drilling of radial branching channels by sectional positive displacement motors
The task of sludge removal to the surface during construction of directional and horizontal wells and strongly curved radial channels is relevant. For stable operation of technical system “Perfobore”, it is proposed to use a circulating sub that ensures efficient cleaning of channel wellbore from the drilled rock. Two schemes of technical system “Perfobore” are considered, consisting of two seven-meter coiled tubing, a positive displacement motor, a bit and one circulating sub in the first scheme and two subs in the second scheme. For each of the schemes CFD modeling was implemented to determine values of pressure and speed. It was found out that the use of two circulating subs in the assembly is more efficient. In order to confirm the numerical experiment, bench tests were carried out. It was determined that the designed circulating sub can eject up to 25 % of pumped drilling fluid. The bench tests of full-size technical system “Perfobore” for drilling 14-meter channels with two circulating subs showed that the axial load on positive displacement motor produced by hydraulic loader was 3000 N and pressure drop depending on flow rate was 1.5-2.0 MPa. This allows the motor to operate at maximum power.
-
Date submitted2021-11-17
-
Date accepted2022-04-06
-
Date published2022-11-10
Method for predicting the stress state of the lining of underground structures of quasi-rectangular and arched forms
- Authors:
- Maksim A. Karasev
- Tien Tai Nguyen
A method for predicting the stress-strain state of the lining of underground structures, the shape of the cross-section of which is different from the circular outline, is considered. The main task of the study is to develop a methodology for assessing the influence of the parameters of the cross-section shape of underground structures on the stress state of the lining. To solve this problem, a method for calculating the stress state of the lining for arched tunnels with a reverse arch and quasi-rectangular forms is substantiated and developed. The methodology was tested, which showed that the accuracy of the prediction of the stress state of the lining is sufficient to perform practical calculations. An algorithm for multivariate analysis of the influence of the cross-sectional shape of underground structures of arched and quasi-rectangular shapes on the stress state of the lining is proposed. Parametric calculations were performed using the developed algorithm and regularities of the formation of the stress state of the lining of underground structures for various engineering and geological conditions, as well as the initial stress state field, were obtained. A quantitative assessment of the influence of geometric parameters of tunnels on their stress-strain state was performed.
-
Date submitted2020-05-15
-
Date accepted2020-06-12
-
Date published2021-06-24
One of the ways to increase the durability of the sectional pump balancing ring
- Authors:
- Nikolai P. Ovchinnikov
The article presents the results of scientific research aimed at struggling the adhesive wear of parts of sectional pumps balancing ring, where the drainage units pumping equipment of the Russian Federation underground kimberlite mines was used as an object of research. It has been theoretically proven and experimentally confirmed that if there is data on the total operating time of a sectional pump in transient modes per day, using the constructed regression model, it is possible to calculate with high accuracy the average operating time of its balancing ring unit to failure. The constructed regression model is applicable only to sectional pumps of drainage units of underground kimberlite mines in the Russian Federation. It is possible to increase the durability of the balancing ring by reducing the acceleration and deceleration time of the sectional pump; for safe operation, it should be at least 10 s. Pilot tests carried out indicate the effectiveness of the proposed method for prompt identification of the critical axial displacement of the sectional pump rotor through the vibration of the discharge tube. The introduction of this method will reduce the cost of repair work to restore the performance of parts of the hydraulic foot to a minimum.
-
Date submitted2019-07-13
-
Date accepted2019-08-31
-
Date published2019-12-24
Method for predicting the stress-strain state of the vertical shaft lining at the drift landing section in saliferous rocks
The article proposes a method for predicting the stress-strain state of the vertical shaft lining in saliferous rocks at the drift landing section. The paper considers the development of geomechanical processes in the saliferous rock in the landing area, the support is viewed as a two-layer medium: the inner layer is concrete, the outer layer is compensation material. With this in view, the paper solves the problem of continuum mechanics in a spatial setting, taking into account the long-term deformation of salts and the compressibility of the compensation layer. Long-term deformation of saliferous rocks is described using the viscoplastic model of salt deformation into the numerical model, and the crushable foam model to simulate the deformation of the compensation layer. This approach considers all stages of the deformation of the compensation layer material and the development of long-term deformations of saliferous rocks, which makes it possible to increase the reliability of the forecast of the stress-strain state of the vertical shaft lining.
-
Date submitted2018-11-20
-
Date accepted2018-12-28
-
Date published2019-04-23
Refined assessment of seismic microzonation with a priori data optimisation
- Authors:
- I. B. Movchan
- A. A. Yakovleva
The work is devoted to the issues of seismic microzonation representativeness, which is amongst the mandatory assessments that precedes civil and industrial construction. In addition to the practical approach and in accordance with the normative documentation, the authors propose parametric interpretation of the remote basis by means of tracing geodynamic zones and elements of the geoblock structure, where the leading marker of seismogenic risk zones is the anomaly of spatial variability of the geofield, coinciding with the discordant intersection of localised land structures. Verification of this marker is achieved by displaying a cartographic distribution image within the range of the seismic point increment, detailed on the basis of approximation dependencies.
-
Date submitted2017-11-22
-
Date accepted2018-01-04
-
Date published2018-04-24
Justification of a methodical approach of aerologic evaluation of methane hazard in development workings at mines of Vietnam
- Authors:
- V. V. Smirnyakov
- Nguen Min' Fen
The methods of evaluation of the aerological conditions to be performed for the purpose of normalization of mining conditions are provided in the present review; the location of possible accumulations of explosive gases during the drift of the development workings are taken into account. To increase the safety of the development working regarding the gas factor, a complex evaluation of a working was developed with respect to the dynamics of methane emission and air coursing along the working which is strongly affected by the character of the leakages from the ventilation ducting. Thereby, there occurs a necessity of the enhancement of a methodical approach of calculation of ventilation of a working which consists in taking into consideration a total aerodynamic resistance of the booster fan including the local resistances of the zones of the working. An integer simulation of the gas-air flows realized on the basis of a software package FLowVision allows to evaluate a change in the methane concentration in the zones of local accumulations.
-
Date submitted2016-11-21
-
Date accepted2017-01-23
-
Date published2017-04-14
Prospects of obtaining samples of bottom sediments from subglacial lake Vostok
- Authors:
- N. I. Vasilev
- G. L. Leichenkov
- E. A. Zagrivnyi
The paper proves the timeliness of obtaining and examining bottom sediments from subglacial Lake Vostok. Predictive geological section of Lake Vostok and information value of bottom sediments have been examined. Severe requirements towards environmental security of lake examinations and sampling of bottom sediments rule out the use of conventional drilling technologies, as they would pollute the lake with injection liquid from the borehole. In order to carry out sampling of bottom sediments from the subglacial lake, it is proposed to use a dynamically balanced tool string, which enables rotary drilling without any external support on borehole walls to transmit counter torque. A theoretical analysis has been carried out to assess the operation of the tool string, which is a two-mass oscillatory electromechanical system of reciprocating and rotating motion (RRM) with two degrees of freedom.
-
Date submitted2009-10-18
-
Date accepted2009-12-17
-
Date published2010-09-22
Reuse of development workings as an element of providing the effective coal output
- Authors:
- M. A. Ilyashov
The article contains the results of application in a coal mine of a combined way for protection and support of development workings. This method combines a frame support, anchors and a cast support strip erected behind the longwale. The geomechanical substantiation of technological parameters, regulations and the field for efficient use of this method are given. Its introduction has allowed to increase the loads on longwale and to lower labour content and expenses for maintenance of butt entries.
-
Date submitted2009-08-16
-
Date accepted2009-10-29
-
Date published2010-02-01
Definition of dependent cadastral value estimation indicators of urban land sections (on the example of Kostomuksha)
- Authors:
- O. Yu. Lepikhina
The work is devoted to the analyze of the connection between indices of urban parcels cadastral value. By using several mail factors composite analyze of urban parcels was done. With the help of statistic methods distribution laws of indices were determined. As a result correlation coefficients were calculated and dependent indices were exposed. In the end of the research the main question was answered: is it right to use analyze of hierarchy method for calculating weights of the indices as it is done in the methods of urban area state cadastral valuation?
-
Date submitted2009-07-12
-
Date accepted2009-09-08
-
Date published2010-04-22
Account and movement of reserves in the information system of Silvinit co.
- Authors:
- A. V. Kataev
- S. N. Kutovoi
- E. M. Efimov
- M. V. Gilev
At ore mines of the Silvinit Co. for accounting and movement of reserves are developed and used special tools, using GIS within the information system. Their use allows to automate accounting and monitoring of status and movement of stocks, including the formation of the reporting tables.
-
Date submitted2008-10-08
-
Date accepted2008-12-08
-
Date published2009-12-11
Georadar investigations of shallow depth оf geological section and engineering constructions
- Authors:
- V. V. Glazunov
- N. N. Efimova
The GPR-method showing high resolution, great performance and sensitivity to minor variations in the composition and conditions of soils and material has assumed a role of the leading geophysical method for looking at the upper part of the geological section. This paper presents the advanced directions of GPR application for engineering problems solution.