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Date submitted2023-06-01
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Date accepted2024-03-05
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Date published2024-08-26
Analyzing friction bolts load bearing capacity in varying rock masses: an experimental study in Anti Atlas Imiter silver mining region, Morocco
This study analyzes how key factors impact friction rock bolt capacity using standard pull-out tests, focusing on 39 mm diameter, 180 cm long split-tube bolts. We investigate bolt performance dependence on rock mass rating (RMR), time after installation, schistosity orientation, surface roughness, and installation quality. The aim is optimizing bolt design and implementation for enhanced underground stability and safety. Results show RMR strongly exponentially correlates with pull-out resistance; higher quality rock masses increase capacity. Anchorage capacity significantly rises over time, especially for RMR above 70. Increasing angle between bolt axis and rock foliation from 0 to 90° boosts pull-out response. Reducing borehole diameter below bolt diameter grows bolt-ground friction. Empirical models estimate load capacity based on RMR, time, orientation, diameter, roughness and installation quality. These reliably predict bolt performance from site conditions, significantly improving on basic RMR methods. Experiments provide practical friction bolt behavior insights for typical rock masses. The data-driven analysis ensures models are applicable to actual underground scenarios. This enables tailored optimization of bolting configurations and supports. Methodologies presented should improve safety, efficiency and cost-effectiveness of reinforced mining and tunneling. Overall, this study fundamentally furthers friction bolt performance understanding, enabling superior underground support design.
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Date submitted2022-09-30
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Date accepted2023-02-13
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Date published2024-02-29
Improving the efficiency of oil vapor recovery units in the commodity transport operations at oil terminals
- Authors:
- Vladimir V. Pshenin
- Gulnur S. Zakirova
In this paper the problem of losses from evaporation of light fractions of hydrocarbons during loading operations of tanker fleets vessels is considered. It was found that there is no unified approach to modeling the system “tanker – gas phase pipeline – vapor recovery units” in open sources. The absence of a generally recognized model makes it impossible to scientifically justify the application of instruments to reducing losses and the development of corresponding measures. In work it is showed that the dynamics of growth of pressure in the inner tanker capacity is described by a differential equation, considering for non-stationary essence of the process. This equation is converted to a non-dimensional form and investigated in relation to the similarity criteria of this system. This research has allowed to establish unambiguously the general character of pressure changes in the inner tanker capacity, and to predict the peak values of its growth at the initial stage of the loading operation. The obtained equations were tested on real tanker loading data and showed satisfactory convergence with the experimental data. At different stages of the loading opera-tion the component composition of vapor changes, which is shown by chromatographic analysis of the gas mixture. With the availability of a model of hydrocarbon vapor displacement from the inner of tanker, it is possible to propose measures to minimize the negative impact on the environment and return valuable vapors of the product to the technological chain of transportation.
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Date submitted2022-04-05
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Date accepted2022-07-21
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Date published2022-11-10
Development of resource-saving technology for excavation of flat-lying coal seams with tight roof rocks (on the example of the Quang Ninh coal basin mines)
- Authors:
- Vladimir P. Zubov
- Le Quang Phuc
It is shown that the creation of the variants of resource-saving systems for the development of long-column mining is one of the main directions for improving the technological schemes for mining operations in the mines of the Kuang Nin coal basin. They provide a reduction in coal losses in the inter-column pillars and the cost of maintaining preliminary workings fixed with anchorage. The implementation of these directions is difficult (and in some cases practically impossible) when tight rocks are lying over the coal seam, prone to significant hovering in the developed space. In the Quang Ninh basin, 9-10 % of the workings are anchored, the operational losses of coal reach 30 % or more; up to 50 % of the workings are re-anchored annually. It is concluded that the real conditions for reducing coal losses and the effective use of anchor support as the main support of reusable preliminary workings are created when implementing the idea put forward at the St. Petersburg Mining University: leaving the coal pillar of increased width between the reused mine working and the developed space and its subsequent development on the same line with the stoping face simultaneously with the reclamation of the reused mine working.
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Date submitted2009-08-22
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Date accepted2009-10-19
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Date published2010-02-01
The substantiation of reinforcing support of preparation mines in the ore massive of the Yakovlevskiy deposit
- Authors:
- Yu. N. Antonov
- V. Yu. Sinegubov
The paper justifies a design of reinforcing mine support of the protective roof at the priority high-grade ore mining site of the Yakovlevskiy deposit. Experience of mine roadway support with the KMP-A3 standing support has been analyzed. A reinforcing support is offered consisting of rock bolts back bracing the ore exposure, which best fits with continuous miner roadheading and consolidating stowing (concrete).
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Date submitted2009-07-24
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Date accepted2009-09-27
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Date published2010-04-22
Influence of geomechanical processes in rock mass on the selection of parameters of technological schemes for flat seams mining at the Leninsk-Kuznetsk coal deposit
- Authors:
- E. P. Yutiaev
The article deals with the aspects concerning the influence of geomechanical processes in rock mass on the selection of parameters of technological schemes for flat coal seams mining. Based on the analysis of experience gained under similar conditions at coal mines of the advanced national and foreign countries, the promising trends in the research work and development projects for the SUEK-Kuzbass Co.were suggested.
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Date submitted2009-07-21
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Date accepted2009-09-28
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Date published2010-04-22
The determination of the volume stress-strain conditions of the rock massive with the circular outline mining ensrined with the anchors
- Authors:
- A. G. Protosenya
- N. A. Belyakov
In the article the analysis of consolidating effect from application of the anchor fastening, which using at driving of transport tunnels in the conditions of North Caucasus is produced. The change of the stress-strain condition of the rock massive, which is weaked by the mining of the circular outline is certain with the finite-elements method. On the basis of the executed design the row of graphic dependences, which describes changing of the sizes of limitary areas depending on strength and deformational properties of the rocks. Due to results of the conducted work the direction of further researches is seted.
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Date submitted2009-07-09
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Date accepted2009-09-03
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Date published2010-04-22
The stress-strain state of the massive of the loose ores in the Yakovlevsky deposit around the minings which were drilled with the combines or with drilling-blast technology
The article presents the consistent patterns of the changes in stress-strain state of the massive by the minings of the first stage of protective overlapping in the Yakovlevsky deposit. The change of the stress-strain condition of the rock massive, which is weaked by the mining was determined by the method of finite elements. The stresses distribution in the massive, the displacement of the contour of the minings, the size of conditional zones of non-linear deformations has been obtained. For stoping passes at the first stage the cutting with combine and application of fastening with the anchors has been suggested.
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Date submitted2008-10-29
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Date accepted2008-12-11
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Date published2009-12-11
Experience in providing the stability of tunnel face and roof during its drivage in proterozoic clays
- Authors:
- V. A. Maslak
Methodology for assessment of state of advance support of face with fiberglass anchors and the working¢s roof – with tube anchors, is given. The results of in-situ experimental observations for efforts in anchors, displacements of excavation and growth of load on the advance supports in its roof are shown.