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Date submitted2024-05-17
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Date accepted2025-03-27
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Date published2025-03-27
Determination of impact hazard potential of rocks in the Norilsk Industrial Region
The deeper the mineral deposits developments are, the worse the mining and geological conditions become. Significant growth of stress level in the rock mass contributes to possible manifestation of rock pressure in dynamic form. The resulting task of assessment of rock impact hazard is closely related to the task of obtaining more accurate results of compression tests of samples in rigid or servohydraulic test presses using graphs of their full deformation. This approach requires special expensive equipment, considerable time resources, and sufficient core material. Therefore, it is important to have an approach that allows to assess the propensity of rocks to brittle fracture with research methods simple enough not to result in the loss of quality and reliability of the obtained results. This paper presents the results of laboratory tests of rocks from the Norilsk Industrial Region to determine their tensile and compressive strengths. Test methods involved both domestic and foreign standards for determining the value of the brittleness coefficient. The impact hazard potential of rocks was determined using the Kaiser criterion. It is found that the tested lithological types (rich sulfide ores, hornblende, disseminated ores, and gabbro-dolerite rocks), with the exception of anhydrite, have a low impact hazard potential.
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Date submitted2021-12-20
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Date accepted2024-05-02
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Date published2024-08-26
A new formula for calculating the required thickness of the frozen wall based on the strength criterion
- Authors:
- Mikhail А. Semin
- Lev Yu. Levin
The study delves into the elastoplastic deformation of a frozen wall (FW) with an unrestricted advance height, initially articulated by S.S.Vyalov. It scrutinizes the stress and displacement fields within the FW induced by external loads across various boundary scenarios, notably focusing on the inception and propagation of a plastic deformation zone throughout the FW's thickness. This delineation of the plastic deformation zone aligns with the FW's state of equilibrium, for which S.S.Vyalov derived a formula for FW thickness based on the strength criterion. These findings serve as a pivotal launchpad for the shift from a one-dimensional (1D) to a two-dimensional (2D) exploration of FW system deformation with finite advance height. The numerical simulation of FW deformation employs FreeFEM++ software, adopting a 2D axisymmetric approach and exploring two design schemes with distinct boundary conditions at the FW cylinder's upper base. The initial scheme fixes both vertical and radial displacements at the upper base, while the latter applies a vertical load equivalent to the weight of overlying soil layers. Building upon the research outcomes, a refined version of S.S.Vyalov's formula emerges, integrating the Mohr – Coulomb strength criterion and introducing a novel parameter – the advance height. The study elucidates conditions across various soil layers wherein the ultimate advance height minimally impacts the calculated FW thickness. This enables the pragmatic utilization of S.S.Vyalov's classical formula for FW thickness computation, predicated on the strength criterion and assuming an unrestricted advance height.
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Date submitted2014-10-02
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Date accepted2014-12-08
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Date published2015-08-25
Assessment of complicated systems quality on the basis of stochastic similarity methods
- Authors:
- D. A. Pervukhin
- A. A. Klavdiev
Modern development of technology is characterized by sharp complication of the tasks solved at production of products, high requirements to their reliability, short deadlines of creation and introduction in operation, aspiration to reduce costs of development of a product at satisfaction of the set conditions. The existing methods of an assessment and quality control of a product by results of tests are often inefficient in the conditions of the determined experiment or the diverse volume-limited statistical information on results of physical modeling, prototyping and tests of a small number of samples available. One of the solutions of the problem of ensuring quality and reliability at a design stage and production of products is an application of the theory of similarity and modeling. In the article the direction of development of the stochastic similarity theory for the effective solution of problems of an assessment and quality control of complicated systems in the course of their creation and operation is offered. The main theorems of similarity are formulated, the criterion of stochastic similarity in the form of the relation of functions of distribution of parameters (characteristics) of systems is theoretically reasonable and experimentally confirmed. Examples of the solution of applied tasks are given. Further development of the theory of stochastic similarity will allow us to advance in the research of non-limiting distributions which are a little described in classical probability theory and mathematical statistics, especially in that their part which will give the chance to manipulate selections of a small volume and censored selections obtaining maximum information from them.
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Date submitted2014-10-13
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Date accepted2014-12-22
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Date published2015-08-25
Optimum operating zones selection methods for multispectral overhead power lines remote sensing devices
- Authors:
- V. A. Shpenst
The article describes the main methodological aspects of designing multispectral optoelectronic devices intended for remote sensing of overhead power lines. Based on proposed indicators and detection criteria a method for selecting operating spectral zones for these devices is suggested, methods of researching into their efficiency and the results of simulating the process of their operation are described.
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Date submitted2009-08-13
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Date accepted2009-10-09
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Date published2010-02-01
Research of the probability of sudden salt rock outbursts on the basis of measuring of their volume shrinkage
- Authors:
- Yu. G. Sirenko
- A. V. Brovko
- A. A. Sankovskii
The article is devoted to research of probability of sudden salt rocks outbursts on the basis of measuring of their volume shrinkage. The design scheme of the device for measuring quantity of the microincluded gases in rocks is proposed. Criteria to estimate the possibility of sudden salt rocks outbursts is revealed.
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Date submitted2008-11-25
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Date accepted2009-01-02
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Date published2009-12-11
Principles and methods of constructing models of contract bidding in outsourcing support-service production
- Authors:
- N. G. Voronov
We consider the principles and methods of construction contract bidding in outsourcing support-service production by the criterion of optimality of the customer, implemented with a minimum expenditure of the funds and ensure the reduction of the cost of production customers.