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Date submitted2023-12-07
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Date accepted2024-11-07
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Date published2025-04-07
Determination of the tangential component of cutting resistance during frozen sedimentary rock cutting using blocked, deeply blocked and cell cutting methods
Due to the insufficient accuracy of existing studies of frozen sedimentary rock cutting process for practical calculations, the article solves the problem of determining the tangential component cutting resistance for blocked, deep blocked and cell cutting, which are currently the most commonly used methods in earthmoving equipment. The cutting tool and rock mass force interaction is considered from the point of view of the emerging stresses, which act on the separated chip element. The analytical dependences for determining the tangential component of cutting resistance were obtained. The numerical explanation of the choice of cell cutting in relation to blocked and deeply blocked cutting is given. For all three methods of cutting, under equal geometrical parameters of the cutting tool and the physical and mechanical properties of the frozen rock, the numerical value of the tangential component of cutting resistance is obtained. The comparison of the cutting resistance estimated values has shown that cell cutting requires relatively less energy and is preferred during the process of frozen sedimentary rock excavation. During field and laboratory investigations with the use of a multi-purpose cutting stand, a sufficient convergence of the analytical statements with the physics of frozen sedimentary rock cutting process was established. The results of the research allow a more reasonable approach to the adjustment of existing methods for determining the required tractive force and power for the drive of an excavation machine, and, therefore, to the actual efficiency and profitability of work.
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Date submitted2023-10-31
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Date accepted2024-11-07
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Date published2025-01-24
Specifics of magnetotelluric studies in Antarctica
One of the priority areas of scientific research in Antarctica is the study of its deep structure. Most of the continent is covered with a thick ice sheet, so the main geoscientific data are acquired using geophysical methods, among which magnetotelluric (MT) ones have the greatest penetration depth and insignificant environmental impact. The possibility of acquiring high-quality MT data in the conditions of the sixth continent has long been questioned. The work is aimed at studying the specifics of magnetotelluric survey in Antarctica. The following tasks were set: to summarize the world experience of studying Antarctica using MT sounding methods; to identify factors that negatively affect the high-quality data acquisition; to determine methods for minimizing the influence of these factors. The article analyses geophysical studies conducted by the magnetotelluric sounding method in the Antarctic region from 1964 to the present. The application of the method is complicated by the following: extremely low temperature affects the drop in the batteries capacity, freezing of the non-polarizing electrodes solution, and changes in the strength properties of materials. Electromagnetic noise occurs during strong winds; proximity to the magnetotelluric field source can violate the plane wave principle on which the method is based. The ice sheet covering most of Antarctica does not allow acquiring optimal values of the contact resistance of the electrode grounding; the extended coastline distorts the acquired data. Studies of the influence of factors complicating the MT sounding method in the coastal and central parts of Antarctica made it possible to formulate recommendations for preparing equipment and adapting the work procedure, modifying the processing flow and a set of measures to ensure safety, the implementation of which will both allow safe performance of geophysical investigations and high-quality data acquisition.
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Date submitted2022-01-20
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Date accepted2022-07-21
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Date published2023-12-25
Tribodynamic aspects of the resource of electric submersible vane pumps for oil production
The operation of electric submersible vane pumps for oil production is accompanied by the presence of solid particles, corrosive substances, asphalt-resin-paraffin deposits in the reservoir fluid, leading to changes in performance characteristics and equipment failures. The reduction of the resource as a result of this is accompanied by an increase in the costs of repair and replacement of equipment. The main processes that negatively affect the failure are the wear of the seals of the working stages, the pump plain bearings and vibration, the level of which can significantly exceed the initial level. A test bench and methodology for testing pump sections for wear in water with an abrasive and simultaneous registration of vibration characteristics have been developed. Two main forms of wear of radial seals have been identified – one-sided and equal-dimensional. The one-sided form of sleeve wear is caused by synchronous shaft precession, whereas the equal-dimensional one is an asynchronous precession, and the vibration level increases with increasing wear. The wear distribution of radial seals along the length of the pump correlates with the shape of the elastic shaft line. The wear of the axial seals does not significantly increase the vibration level. During wear the frequency spectrum of vibrations changes; there occurs a frequency that can serve as a diagnostic sign of ultimate wear of the pump. The calculated dependence of the vibration velocity on the wear of the radial seals of the working stages is obtained, which makes it possible to predict the onset of a failure of functioning.
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Date submitted2021-04-30
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Date accepted2021-11-30
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Date published2021-12-27
Methodology for testing pipeline steels for resistance to grooving corrosion
- Authors:
- Viktor I. Bolobov
- Grigoriy G. Popov
The methodology for testing pipeline steels is suggested on the assumption that for the destruction of pipes in field oil pipelines by the mechanism of grooving corrosion the simultaneous fulfillment of such conditions as the occurrence of scratches on the lower generatrix of the pipe, eventually growing into a channel in the form of a groove, emulsion enrichment with oxygen, presence of pipe wall metal in a stressed state, presence of chlorine-ion in the oil-water emulsion is required. Tests are suggested to be carried out in 3 % aqueous solution of NaCl with continuous aeration by air on bent plates 150×15×3 mm, made of the analyzed steel, the middle part of which is under the action of residual stresses σ res , close to the level of maximum equivalent stresses σ eqv in the wall of the oil pipeline, with the presence of a cut on this part on the inner side of the plate as an initiator of additional mechanical stresses. Using the value of the modulus of normal elasticity of the analyzed steel, the degree of residual strain of the elastic-plastic body from this material, corresponding to the value σ res ≈ σ eqv is calculated, based on which the plates are bent to the required deflection angle, after which the cut is applied to them. After keeping the plates in the corrosive medium for each of them the increase in depth of the cut as a result of corrosion of the walls by the corrosive medium is analyzed, from which the rate of steel K by the mechanism of grooving corrosion is calculated taking into account the duration of tests. Corrosion rate values for two pipe steel grades determined by the suggested procedure are given. The comparison of K values obtained leads to the conclusion about the higher resistance to grooving corrosion of 09G2S steel.
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Date submitted2021-04-19
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Date accepted2021-10-18
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Date published2021-12-16
Mutual spectral densities calculation of the moments of resistance on the peat milling unit working bodies
- Authors:
- Konstantin V. Fomin
When performing technological operations in the peat industry, various units with milling-type working bodies are used. They differ in design, layout, number and type of cutting elements, operating modes, and may have one or more working bodies. During operation, random forces and moments act on the cutters, which have a dramatically variable nature, which is associated with the periodic interaction of the knives with the peat deposit, its structural heterogeneity, variations in the milling depth, physical and mechanical properties of peat, the rotational speed of the cutter and the movement speed of the machine. In this case, significant dynamic loads arise in the structural elements, which leads to a decrease in their reliability, deterioration of the energy characteristics of the engine operation and technical and economic indicators of use. In the dynamic analysis of drive elements, when using machines with several working bodies, it is necessary to know both spectral and mutual spectral load densities. For their calculation, expressions were obtained that take into account the physical and mechanical properties of peat, the operating modes of the unit and their probabilistic characteristics, as well as the design features of the working body. The expressions are obtained for the case when there are several working bodies with the same diameters and the number of knives in the cutting plane. In this case, the number of planes, width, type of cutting element and type of cutting (locked, semi-locked, etc.) may differ. As an example of using the developed approaches, the calculation of spectral and mutual spectral densities of moments on cutters and loads in the drive elements of the machine for surface-layer milling MTF-14 is presented.
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Date submitted2021-03-05
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Date accepted2021-10-18
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Date published2021-12-16
Physical and mathematical model of rock destruction by a milling machine cutter
As a result of the analysis of the work on rock destruction by cutters of milling of machines, it was found that the existing developments do not allow us to proceed to the derivation of calculation d dependencies for determining fracture resistance, or can be used only in preliminary calculations of the known by design parameters of milling machines. To eliminate these disadvantages, a combined physical and mathematical model of the process of interaction of a single milling cutter with a spherical tip with the rock has been developed. Consideration of the physical picture of the action of forces and stresses acting from the cutter with spherical tips on the separating rock element in the limiting condition allowed to describe analytically the components of total resistance, which are the mathematical part of the physical and mathematical model of rock destruction by cutters. Analytical dependences for determining the tangential and normal components of fracture resistance of rocks of medium hardness have been obtained. The adequacy of the physical and mathematical model to the physical process of destruction of rocks of different hardness by cutters on a universal stand was tested both in the field and in the laboratory conditions. Technical evaluation of the results of experimental studies confirms the reliability of the developed physical and mathematical model.
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Date submitted2020-05-15
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Date accepted2020-06-12
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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.
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Date submitted2019-06-19
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Date accepted2019-09-11
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Date published2020-02-25
Method for estimating the spectrum density of the resistance moment on the working body of a peat milling unit
- Authors:
- K. V. Fomin
The main source of dynamic loads in the drive elements and the design of the peat milling unit is the working body. The forces of external resistance arising in the process of performing a technological operation are sharply variable, random in nature. The article proposes a model of formation of the moment of resistance on the mill when interacting with peat. The case when there are several cutting planes with the same radius at the ends of the cutting elements is considered. When developing the model, it was taken into account that the operating conditions of the knives, determined by the type of cutting (blocked, semi-blocked, etc.), their width and type in each cutting plane can vary. Factors that determine the nature of loading, such as the frequency of interaction of the cutting elements with the fallow and the randomness of the operating conditions of the unit, lead to the presentation of the loads in the form of a sequence of pulses with random parameters. Expressions are obtained for determining the spectral density of the moment of resistance on the mill at the design stage, taking into account its design, operating modes, physico-mechanical properties of peat and their probabilistic characteristics. To illustrate the application of the developed approaches, a technique is presented for determining the spectral density of the moment on the working body of deep milling machines and in their drive elements based on a linear model. An example of calculation is given, and the obtained expressions are verified on the basis of experimental data. The probabilistic characteristics of the loads on the mill serve as initial information for the dynamic analysis of the drive system and the design of the unit, its strength analysis, the selection of optimal parameters and operating modes.
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Date submitted2019-03-13
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Date accepted2019-09-19
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Date published2020-02-25
Specifying the technical state limit value of the pump pulp without disassembling
The northern part of the territory of the Republic of Sakha (Yakutia) is rich in vast deposits of diamonds. These deposits are developed by the mining company “Almazy Anabara”, which is engaged in the extraction of diamonds at seasonal processing plants using various technological equipment. One of the key types of equipment is the pulp pump of a foreign company “KETO”. The work of pulp pumps of this company in the enrichment of diamond-containing raw materials is accompanied by intensive hydroabrasive wear of their impellers, the service life of which usually does not exceed three months. In practice, untimely replacement of a worn impeller can lead to emergency breakdowns of sealing elements and bearings, which is explained by super-permissible deflections of the shaft of pumping equipment arising from a significant unbalance of the rotor. The main cause of breakdown of slurry pumps at “Almazy Anabara” seasonal processing plants is the inability to quickly identify their ultimate technical condition, the key sign of which is the maximum wear of the impeller. The seasonal beneficiation plants of “Almazy Anabara” currently need a simple and at the same time reliable diagnostic sign of pulp pumps reaching their ultimate technical state, the identification of which can be quickly performed without disassembling and using complex equipment, which is very important when operating pumping equipment in short wash season on the Far North.
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Date submitted2019-07-23
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Date accepted2019-09-19
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Date published2019-12-24
Estimation of abrasiveness impact on the parameters of rock-cutting equipment
Development of equipment, which provides access to underground mineral deposits and their extraction, requires the use of all the accumulated experience and advanced scientific research in the area of mechanical rock cutting. The most important issues of using mechanical rock cutting tools are their wearability and consumption, which have an impact on technical and economic indicators of project efficiency. The paper describes Russian and foreign practices of estimating tool wear resistance, expressions to determine critical cutting speed, methods to evaluate tool consumption. It is demonstrated that wearability of mechanical tools and associated effects are to a large extent defined by rock abrasiveness. It is highlighted that in Russia the index is calculated using Baron-Kuznetsov method, which is briefly described in the paper. In many countries with a highly-developed mining industry, rock abrasiveness is estimated with a Cerchar Abrasiveness Index (CAI), recommended by the International Society for Rock Mechanics. Its description is also presented in the paper.
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Date submitted2018-11-03
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Date accepted2019-01-16
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Date published2019-04-23
Interpretation of the tracer investigation results considering convective mass transfer
- Authors:
- V. A. Korotenko
- S. I. Grachev
- A. B. Kryakvin
The paper discusses the results of interpreting well tracer studies. It is shown that from the law of mass conservation it follows that when filtering a volume of an indicator, part of the injected tracer flows into the matrix. With the flow of fluid containing the indicator from the low-filtration resistance channel (LFR) into the surrounding matrix, the linear dimensions of the flow area depend on the permeability and porosity properties of the high-permeability channel and the matrix. While another part of the tracer moves toward the production well, its mass is lost due to diffusion processes. From the solution of the diffusion equation, it follows that the initial concentration of the tracer decreases in the course of filtration along the LFR channel. To interpret the results of the tracer studies, different cases of the LFR channels' location in the volume of the productive formation are considered. The varied parameter w allows characterizing the presence of several peaks in the concentration of the indicator and calculation the filtration parameters of the LFR channels. Depending on the known technological indices, several methods for determining pore volumes in the LFR channels have been proposed. To reduce the water cut in producing wells and to apply the technology of changing or aligning the injectivity profiles, calculations of the pore channels' radii in the mass of highly permeable seams are presented. It is shown that the volume of the chemical reagent pumped into the injection well to isolate the LFR channel is affected by the linear dimensions of the drainage area for the aqueous solution of indicator. Examples of the calculation for the permeability and porosity parameters of the LFR, the volume of pore channels necessary to isolate water inflow, and the radii of pore filtration channels, which influence the selection of the size of chemical reagent molecules, are given.
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Date submitted2018-11-05
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Date accepted2019-01-15
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Date published2019-04-23
Some aspects of antifriction coatings application efficiency by means of finishing nonabrasive antifriction treatment
- Authors:
- M. I. Sidorov
- A. V. Ragutkin
- M. E. Stavrovskij
The article analyzes the effectiveness of anti-friction coatings obtained by finishing anti-friction non-abrasive treatment (FANT), including processing in metal-clad technological media, in order to improve the performance of machine parts. The analysis of the application of coating technologies FANT on materials operating at elevated temperature and at high pressure, as well as with high values of energy fluxes in the environment, was carried out. The results of the application of various compositions of cladding elements and FANT technologies for various engineering products are presented. The results of studies of the use of FANT technologies developed with the participation of the authors confirm their high efficiency for improving the wear resistance of artillery gun barrel materials. Decrease in wear ranging from two to three times compare to regular technology. Field testing of anti-friction anti-wear coatings, carried out by specialists of the FSE SRI «Geodesia», confirmed the prospects of this direction for increasing the survivability of artillery barrels.
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Date submitted2018-09-04
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Date accepted2018-11-18
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Date published2019-02-22
Operation experience of centrifugal single-stage pumps in «ALROSA» Joint Stock Company
- Authors:
- N. P. Ovchinnikov
When mining diamond-bearing raw materials and further extracting diamonds from it in the joint-stock company ALROSA, which is a city-forming enterprise in the north-east of the Russian Federation, various pumping equipment is used, in particular, centrifugal single-stage pumps. In the present work, it is noted that the least reliable in terms of absence of failures of centrifugal single-stage pumps used in the joint-stock company ALROSA are the impellers, seals and bearing assemblies. Using linear correlation and regression analysis, it was found that the durability of the seals and bearing assemblies of the investigated pumps largely depends on the durability of their impellers. In the course of research, it was found that unbalancing the pump rotor due to excessive hydroabrasive wear of the impeller also leads to deformation and fracture of the shaft. In general, residual deformations and destructions are characteristic of the shafts of domestic pulp pumps of GrAT, GrT and Gr types. The most loaded sections of shafts of centrifugal single-stage pumps are installed. The most effective from the point of view of application among the pulp (ground, slurry and sand) pumps are pulp pumps of the Finnish company «Metso». When working on highly mineralized water (brines), the «X» type pumps have proven to be the best among centrifugal single-stage pumps.
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Date submitted2018-08-30
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Date accepted2018-10-26
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Date published2019-02-22
Study of bearing units wear resistance of engines career dump trucks, working in fretting corrosion conditions
- Authors:
- Ju. Olt
- V. V. Maksarov
- V. A. Krasnyy
The occurrence of fretting corrosion on nominally fixed surfaces of high-loaded parts of mining machines and mechanisms is considered. Examples of wear and damage of critical parts, bearing assemblies of engines of dump trucks in fretting conditions are given. The mechanisms of fretting corrosion when using wear-resistant coatings are considered. It is noted that when choosing protective thin-layer coatings that provide an increase in the fretting-resistance of surfaces of tightly contacting parts, it is necessary to take into account both their wear resistance and the ability to resist shear. At the same time, the thickness of such coatings allows preserving, during operation, those provided during the assembly of the tension, without disturbing the maintainability of the nodes. The results of research of fretting wear of a number of coatings on a special installation are given. The mechanisms of wear of a number of thin-layer coatings based on friction-mechanical brazing, polymer fluorocarbon composition, solid lubricant coating using scanning electron microscopy were studied. Recommendations on the use of the studied thin-layer coatings for high-loaded parts of mining machines operating in fretting corrosion conditions have been developed. The aim of the work was to study the effect of a number of thin-layer coatings on the wear of highly loaded connections of the mechanisms of mining machines, in particular bearing assemblies of quarry dump trucks operating under fretting corrosion conditions.
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Date submitted2018-05-21
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Date accepted2018-07-14
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Date published2018-10-24
Increasing the wear resistance of adapters and drill pipes by elec-tromechanical processing
The directions of the research on increasing the wear resistance of drill pipe locks, threaded joints and casing drill string have been defined: application of drill pipes from the nose-resistant surfacing to the lock with Russian and foreign materials (hardbanding); hardening of the surface layer of drill pipe locks by electromechanical processing; hardaning of the external and internal locking thread of drill pipes by electromechanical processing. Comparative tests of the wear resistance of various hardening materials (hardbanding) of Russian and foreign production and the drill pipe lock without surfacing have been made. The recommendations for increasing the wear resistance of threaded joints by the method of electromechanical processing are developed, which determine the ways of increasing the resource and reliability of drill pipes and sub-assemblies, the formation of unique properties of parts, reducing the labor-capacity of manufacturing and restoring parts, increasing the efficiency of enterprises and organizations, protecting the environment and creation of competitive products. The materials of the article are of practical value for specialists of various fields engaged in the issues of increasing the reliability of technological equipment. The production success of using wear resistant surfacing technology on the body of a drill pipe joint is due to the possibility of using relatively simple and mobile welding equipment, carrying out work in the places of use of a drilling tool or temporary (permanent) production bases with a small transport arm from the field, re-depositing surfacing materials restoration of drill pipe locks; a wide and growing list of companies that receive accreditation for the production of these works.
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Date submitted2018-05-03
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Date accepted2018-07-07
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Date published2018-10-24
Regularities of material destruction of the impactor in repeated single punch
- Authors:
- V. I. Bolobov
- Le Tkhan' Bin
The technique and the results of experiments on the study of the laws of the process of the cone-shaped tip of a freely falling impactor made of 38HM, U8, H12MF steels, subjected to typical heat treatment and additionally treated with cold, when they apply multiple (up to 10000) single impacts on granite under conditions approaching hydraulic impactor peaks. To explain the processes, we used the values of stresses σ к , arising at the contact area of the impactor and the rock, calculated using the developed mathematical model. It has been established that the process of wear of an impactor with multiple single blows proceeds in three stages separated by critical values, , which correspond to the strength characteristics of the material of the impactor demonstrated in these dynamic conditions. With a small number of strokes (n ≤ n * ) and the small size of the blunting area (stage I interaction) values σ c exceed of steel and it is exposed to local destruction at the contact site, which is recorded as a significant loss of the impactor’s mass; with n * < n ≤ n ** (stage II) the resulting stresses are not enough to destroy the material, but it is enough for its plastic deformation, accompanied by the movement of metal from the central part of the contact area to the peripheral and the destruction of part of the deformed metal by rock; with n > n ** (stage III) arising σ к do not reach the level and the decrease in the mass of the impactor is determined by the resistance of the steel to abrasion by the products of rock destruction, displaced by the impactor from the well. The treatment of impactors from all tested steels with cold leads to an increase in their wear resistance; The total depth of the holes punctured by the cold-treated H12MF steel impactor at the time of the interruption of the rock penetration is four times higher than that of the 38HM steel impactor subjected to typical heat treatment.
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Date submitted2017-11-22
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Date accepted2018-01-04
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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.
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Date submitted2017-09-11
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Date accepted2017-10-30
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Date published2018-02-22
Provision of adhesion strength of gas-thermal coatings on piston rings of quarry transport engines
- Authors:
- Yu. Olt
- V. V. Maksarov
- V. A. Krasnyi
The main trend in the development of modern diesel engine manufacturign is the creation of high-powered, reliable and economical internal combustion engines (ICE), which are widely used in various industries, including mining machinery. The application of the methods of gas-thermal and gas-plasma coating for obtaining wear-resistant layers on piston rings for large internal combustion engines of quarry transport – diesel locomotives and dump trucks- is considered. It is shown that the abrasive-jet machining of base coat is widely used as a preparatory operation before coating process, and the roughness of the working surface of the rings after abrasive-jet machining has a significant impact on the adhesion strength of the coating with the base material. The selection of the surface roughness and the conditions of abrasive-jet machining for increasing the coating adhesion strength to the base coat significantly determines both the thickness of the coating and the reliability of the part itself. The aim of the paper is to investigate the dependence of the adhesion strength of a gas-thermal wear-resistant coating of piston rings of large engines of quarry transport, including dump trucks and diesel locomotives, from the roughness of the working surface after abrasive-jet machining, which in turn depends on its modes (distance to the nozzle exit section, the number of passes, the working air pressure, the shot change rate). The working surface adhesion strength of piston rings with diameter of 210 mm coated with molybdenum and steel wire composition was investigated by the twisting angle at which the coating peeled. It is shown that the roughness providing a twist angle greater than 35° should be more than 22 μm, which does not cause coating peeling off. Modes of abrasive-jet machining providing the specified values of roughness: working air pressure is 0.4 MPa, distance to the nozzle exit section is 110 mm, the number of passes is 2, and the shot changes after processing 40 mandrels.
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Date submitted2017-09-17
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Date accepted2017-11-06
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Date published2018-02-22
Collaborative interpretation of the data obtained by resistivity and ground penetrating radar methods for assessing the permeability of sandy clay soils
- Authors:
- D. A. Lalomov
- V. V. Glazunov
A method for estimating the filtration factor of sandy clay soils is considered on the basis of a joint interpretation of the data of a set of methods of engineering electrical exploration, including electrical resistivity tomography and ground penetrating radar studies. The solution of this problem is based on the use of known empirical connections between the imaginary and real parts of the complex dielectric permittivity, specific electrical resistance, and Q factor. An example of the effective joint use of the ground penetrating radar and non-contact electrical resistivity tomography shows how to obtain qualitative and quantitative estimates of a changing filtration factor in a draining road layer. It is necessary to use precise engineering geological information in order to provide the required estimates. The proposed approach makes it possible to describe continuous profiles of a pavement and underlying layers by ground penetrating radar and electrical resistivity tomography, as well as to assess soil properties when conducting an electrical survey from the surface of asphalt concrete pavement. Recommendations for the implementation of the developed methods of complex engineering and geophysical research are given for solving issues of repair work design, supervision, and quality control of road construction.
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Date submitted2015-08-25
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Date accepted2015-10-01
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Date published2016-04-22
Vibrodiagnostics of the technical state slurry pumps
- Authors:
- V. I. Aleksandrov
- Irzhi Sobota
Analysis of the work hydrotransport systems in processing plants shows that the efficiency of this type transport does not match its technical capabilities: the high laboriousness involved in the operation of the equipment, high hydroabrasive wear of slurry pumps and pipelines, low working life pumps, high metal consumption and energy. The main reason for the lack of effectiveness of hydraulic transport is hydroabrasive wear impellers of slurry pumps, causing rising levels of vibra-tion pumps, reducing the pressure characteristics, general technical state of hydrotransport system and as a result - low pumps life, not exceeding 500 hours of continuous operation. In paper, it is shown that as a criterion of period normal operation slurry pump can be used coefficient of techni-cal state, the value of which is proportional to the relative head, degree of hydroabrasive wear of the impeller and time of continuous operating. The coefficient technical state of slurry pump can be represented as a function of current flow rate and the RMS value of vibration velocity. The re-sults of theoretical and experimental studies used to develop algorithms and techniques express-diagnosis and monitoring of slurry pumps in hydrotransport system, data which indicate the need for routine maintenance of pumping equipment.
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Date submitted2014-12-11
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Date accepted2015-02-11
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Date published2015-12-25
Influence of the type of hardening treatment on wear-resistant materials of mining equipment
- Authors:
- V. I. Bolobov
- S. A. Chupin
For example, steel 110G13L as the material of teeth of excavator buckets, shows that the work hardening (hardening) is an effective means to increase (up to 10 times) the wear resistance of components in contact with abrasive media, such as marble, yielding the steel in a state of hard-ening of hardness. In the case of wear on the rocks (granite, gabbro) with a hardness greater than the hardness of steel, the effect of hardening has almost no effect. It was found that high-temperature thermomechanical treatment of steel 35HGSA as the material of holders of rotary cut-ters (strain at 900 С, water quenching, tempering at 230 С) leads to a substantial increase of its hardness (23 %) and durability (38 %) compared to typical heat treatment used in the manufacture of cutting tools at the factory.
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Date submitted2010-07-16
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Date accepted2010-09-06
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Date published2011-03-21
The aboveground oil pipeline temperature regimes calculation
- Authors:
- S. Yu. Trapeznikov
The theoretical and experimental investigations of the highviscosity oil transportation temperature regimes to improve the pipeline efficiency are caused by the insufficient knowledge of its heat transfer process. The dependencies for the hydraulic resistance coefficient and the dimensionless heat transfer coefficient of Nusselt are proposed.
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Date submitted2010-07-10
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Date accepted2010-09-04
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Date published2011-03-21
Experimental research of the train aerodynamic resistance
- Authors:
- V. A. Pleskunov
In paper the technique of definition of aerodynamic resistance of the train, a being main component of a piston pressure is resulted. The urgency of the given theme is caused by essential influence of a piston pressure on distribution of fresh air on a tunnel and accordingly on safe operation of railway tunnels.
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Date submitted2010-07-14
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Date accepted2010-09-07
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Date published2011-03-21
Substantiation of pumped volumes of flow angularity compositions in injection wells
- Authors:
- A. R. Mavliev
- M. K. Rogachev
- D. V. Mardashov
The method of calculation pumped volumes of flow angularity compositions in injection wells, which based on combination of the seepage theory, laboratory investigation and field experience is developed.
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Date submitted2010-07-18
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Date accepted2010-09-20
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Date published2011-03-21
Analyses of technologcal characteristics of diamond drilling of hard rock
- Authors:
- V. G. Gorelikov
- Van Dong Vu
The classification of different diamond bit types for drilling of jointed rock is offered. It is based on two predominant types of wear: mechanical and thermo physical. The facial and lateral on matrix body as well as cracks along the matrix body, spalling of the matrix sectors and normal wear are attributed to the mechanical type of wear. The proposed classification includes main types of wear at jointed rocks drilling and creates the grounds for the designing of rock-distributing tool more resistant to mechanical and thermo physical wear.