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Date submitted2022-03-14
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Date accepted2022-06-20
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Date published2022-11-10
Model of a walking sampler for research of the bottom surface in the subglacial lake Vostok
Technologies and technical means for investigation of subglacial lakes in Antarctic is a new developing scientific and technical direction, which today has no clearly established methodology. Based on the developed technology of drilling a new access well to lake Vostok and its penetration as well as analysis of existing methods and devices for bottom sediment sampling, a basic model of a sampler with a walking-type mover, capable of moving along different trajectories and operating in a wide technological range, is proposed. The proposed device model is equipped with different actuators for sampling the bottom surface with different physical and mechanical properties. Based on the presented basic model of the walking sampler, a mathematical model of the device was developed, which was based on the theoretical mechanics methods. As a result of conducted research the dependencies were obtained, which allow making a scientifically justified choice of optimal values for geometric and force parameters of the walking sampler. A conceptual design of the walking sampler has been developed, taking into account the mutual location and coupling of its main components, the overall dimensions of the delivery tool, as well as the esthetic component of the device.
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Date submitted2021-03-05
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Date accepted2021-04-28
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Date published2021-09-20
Rational design justification of the tunnel boring shield executive body for the conditions of the mines of Saint Petersburg Metrostroy
The article discusses the features of running tunnels in difficult mining and geological conditions of the Saint Petersburg Metrostroy using modern tunnel boring shields of Herrenknecht company with hybrid executive bodies equipped with a incisors and rock cutters. The work of a hybrid executive body is analyzed when driving along a heterogeneous bottomhole massif consisting of Cambrian clay with limestone interlayers. Theoretical and experimental studies of vibroactive cones, a graphical representation of the dependence of the depth of their penetration on the axial force and axial force together with the applied shock load (the dependences of the penetration depth are interpreted as a linear dependence) have been carried out. An increase in the intensity of destruction of a heterogeneous bottomhole massif consisting of Cambrian clay and limestone interlayers using vibroactive rock-cutting tools (spiked roller) was theoretically and experimentally confirmed, while the growth of the penetration rate is determined depending on the number of their parameters. The design is considered, the principle of operation and the method of power calculation of a rotary executive body equipped with vibroactive cutters are described, on the basis of which a nomogram of the dependence of the torque and performance of the tunnel boring shield on the feed rate of the executive body to the bottom is built.
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Date submitted2020-05-28
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Date accepted2020-05-28
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Date published2020-06-30
The age of mineralization of Mayskoe gold ore deposit (Central Chukotka): results of Re-Os isotopic dating
The article presents the results of the sulfide mineralization dating of the Mayskoe gold ore deposit using the Re-Os isotope system and isochron age estimation method of the main sulfide minerals: arsenopyrite, pyrite, and antimonite. The complex multistage formation of the studied sulfides, as well as the close intergrowths of genetically different mineral phases, did not allow obtaining a single rhenium-osmium isochron corresponding to the formation time of sulfide mineralization. Isochrones for single minerals, collected from each sulfide sample, turned out to be the result of isotopically distinct components mixture (radiogenic crustal and non-radiogenic mantle) and do not make sense from the geochronological point of view. In terms of geology, the most significant result of the study is an age estimation of 128.8 ± 4.4 Ma, obtained for the sulfide mineralization of Mayskoe deposit using Re-Os isotope dating of single fractions of pyrite and antimonite of the ore mineralization stage. While arsenopyrite is most closely associated with gold mineralization, one of the arsenopyrite varieties corrodes framboidal pyrite of the pre-ore stage, has a maximum of the crust component in the osmium isotopic composition and forms a mixing line in the isochron diagram with an apparent formation age of 458 ± 18 Ma. The initial osmium isotopic composition of the studied sulfides indicates a mixed mantle-crust source of sulfide mineralization. The issue of simultaneous ore genesis and granitoid magmatism in the Mayskoe deposit remained unresolved (the age of granitoids according to the U-Pb zircon system is 108 Ma). However, a possible solution could be the further determination of the Re-Os isochron age of the ore mineralization sulphides from the single paragenesis of a specific sample containing both arsenopyrite and pyrite (+ antimonite) with gold.
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Date submitted2015-08-26
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Date accepted2015-10-16
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Date published2016-04-22
Reserch of modernized perforator-hammer for drifting special roadway the underground mines «Metrostroy»
- Authors:
- D. A. Yungmeister
The article describes the design of modernized hammer-perforators for tunnel complexes for construction of auxiliary mine workings of «Metrostroi», St Petersburg, protected by patents. The article deals with assembly variants of the executive device of percussion type for breaking faces of complicated structure. Particular attention is paid to hammers working in the mode of the «counter-shearing» accomplished by dual jackhammers. The results of experimental tests to determine pike penetration into rock array for different values of rock hardness and pressing force. It is noted that the proposed solution replaces manual labor, reduces working cycle time.
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Date submitted2009-10-21
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Date accepted2009-12-26
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Date published2010-09-22
Modeling of geomechanical processes in mining the steeply pitching ore bodies of rockburst-hazardous deposits
The article contains the results of numerical modeling of stress-strain state in constructive elements of mining systems, applied at hazardous and prone to rook bursts deposits of the Far-East. Consideration is given to some stated regularities of forming of teсhnogenic stress field and geomechanical processes proceeding in rock mass of minable deposits which allow to substantiate a сomplex of measures for prevention of dynamic rock pressure manifestations.