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ISSN 0536-1028 (Print) ISSN 2686-9853 (Online) |
УДК 622.271.333 | DOI: 10.21440/0536-1028-2019-8-47-57 | Download |
Abstract
Introduction. Opencast mining is complicated by a number of negative events. The problem of slopes instability plays a special part. In the conditions of modern economy, when the growth of mineral production is inevitable, human protection and work cycle permanence are the criteria of mining enterprises productivity. The actions aimed at protecting against landslides being developed and landslides that took place when carrying out opencast mining operations at the f elds of Kuzbass, Transbaikal, Republic of Kazakhstan, Republic of Uzbekistan, the USA, and Poland prove that it is crucial to f nd the solution to this problem. At the same time, particular features of the mentioned f elds are complex engineering-geological and hydrogeological conditions. One such f eld is Angren brown coal f eld.
Research aim is to determine engineering-geological and hydrogeological factors infuencing the development of landslides.
Methodology. Engineering-geological conditions of Angren brown coal feld have been analyzed, together with the results of surveying instrumental and hydrogeological observations.Results. Geological structure of Angren brown coal feld area includes the rocks of the Paliozoic foundation and the Mezo-Cenozoic deposits. Hydrogeological conditions of the feld include four diferent water-bearing strata and complexes, which infuence the development of landslides: quaternary, Neogene, the Cretaceous-Palaeogene, and Jurassic deposits. Drainage pattern of a feld is represented by ravines with
permanent or temporary watercourse (“sai” in the Kazakh language) and the watercourse itself: Saiak-sai, Badamzar-sai, and Boksuk-sai. The expansion of engineering activities connected with feld development, resulted in some negative efects which infuence the stability of slopes: discharge of subsurface waters on the surface of slopes, reduction of strength characteristics in the zones of disjunctive faults, shale hydration, development of fracture zones in weathering crust rock, and variation of stress. The most hazardous landslide is Tsentralny. As of 2017–2018, the area of the landslide cirque reached 1.06 km2, volume – 120 million m3. By the results of surveying instrumental observations, the following
displacement periods have been determined: most intensive – from January to May 2018, least intensive – from May to December 2018. The analysis of drainage water delivery in 2017–2018 shows that maximum increase in the level of ground waters is in spring (March – May).
Conclusions. Together with deviations from design parameters of slopes (slope angle increases, strata contacts trim, etc.), one main reason of landslides is unfavorable combination of engineering-geological and hydrogeological factors: high water permeability of enclosing rock represented by loam, pebble, and gravelite, and rush of ground water from surface sources, precipitation, and overfow along the fractures reservoir rock.
Key words: landslide; stability of slopes and benches; engineering-geological conditions; hydrogeological conditions; surveying; ground water level.
REFERENCES
Received 6 May 2019
УДК 622.011:539.3 | DOI: 10.21440/0536-1028-2019-8-38-46 | Download |
Abstract
Introduction. One most dynamically developing method of preventing rockbursts and tectonic rockbursts
is the control of geomechanical state of rockburst hazardous rock mass with the use of the automated
systems which inform of geomechanical and geodynamic processes within the rock mass in real time.
The crucial component of such systems is a distributed observation network of underground digital
receiving transducers.
Research aim is to study the infuence of a particular modifcation of a primary transducer on the accuracy
of determining the values of amplitude, frequency, energy parameter of simulation seismoacoustic efects
and errors in seismoacoustic sources coordinates calculation.
Methodology. Research presented in the article are based on a range of experiments carried out in
Nikolaevsly mine of MMC Dalpolimetal JSC. Results were recorded and processed with Prognoz ADS
seismoacoustic system of rock pressure. Experiment included inducing simulation seismoacoustic impacts
of various origin and various distance from receiving transducers on a rock mass.
Results. The comparison of statistic characteristics of seismoacoustic impact impulses hasn’t revealed
signifcant infuence of primary transducer type on the calculation of the values of coordinated and energy
characteristic of simulation sources.
Summary. The research and conclusion about insignifcant infuence of primary transducer body material
on the characteristics of seismoacoustic signals will make it possible to reduce the prime cost of geophones
manufacture without compromising the quality of signal recording, and direct the resources to
geomechanical safety system expansion and maintenance.
Key words: rockburst hazard; geomechanical monitoring; seismoacoustic activity; acoustic manifestation;
microseismic event; primary transducer.
REFERENCES
1. Rasskazov I. Iu. Rock pressure сontrol and management in the Far East mines. Gornaia kniga Publishing;
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2. Rasskazov I. Iu., Iskra A. Iu., Kalinov G. A., Anikin P. A., Gladyr A. V., Rasskazov M. I., Sidliar A. V.
The peculiarities of recording and processing the data of geoacoustic control of rock mass in an operating
mine. Gornyi informatsionno-analiticheskii biulleten (nauchno-tekhnicheskii zhurnal) = Mining
Informational and Analytical Bulletin (scientifc and technical journal). 2011; 8: 212–218. (In Russ.)
3. Zhou K. P., Lin Y., Deng H. W., Li J. L., Liu C. J. Prediction of rockburst classifcation using cloud
model with entropy weight. Transactions of Nonferrous Metals Society of China. China. 2016;
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4. Meifeng C. Prediction and prevention of rockburst in metal mines – A case study of Sanshandao gold
mine. Journal of Rock Mechanics and Geotechnical Engineering. 2016; 8; 2: 204–211.
5. Ma T. H., Tang C. A., Tang L. X., Zhang W. D., Wang L. Rockburst characteristics and microseismic
monitoring of deep-buried tunnels for Jinping II Hydropower Station. Tunnelling and Underground Space
Technology. China. 2015; 49: 345–368.
6. Shan-Chao Hu, Yun-Liang Tan, Jian-Guo Ning, Wei-Yao Guo, Xue-Sheng Liu. Multiparameter
monitoring and prevention of fault-slip rock burst. Shock and Vibration. 2017; 2017; Article ID 7580109.
8 p. https://doi.org/10.1155/2017/7580109
7. Rasskazov I. Iu., Petrov V. A., Gladyr A. V., Tiurin D. V. Streltsovsky ore feld geodynamic polygon:
practice and prospects. Gornyi zhurnal = Mining Journal. 2018; 7: 17–21. (In Russ.)
8. Rasskazov I. Iu., Dolgikh G. I., Petrov V. A., Lugovoi V. A., Dolgikh S. G., Saksin B. G., Tsoi D. I. Laser
strainmeter in integrated geodynamic monitoring within Streltsov Ore Field. Fiziko-tekhnicheskie problemy
razrabotki poleznykh iskopaemykh = Journal of Mining Science. 2016; 6: 29–37. (In Russ.)
9. Rasskazov I. Iu., Tsirel S. V., Rozanov A. O., Tereshkin A. A., Gladyr A. V. Application of acoustic
measurement data to characterize initiation and development of disintegration focus in a rock mass. Fiziko-
tekhnicheskie problemy razrabotki poleznykh iskopaemykh = Journal of Mining Science. 2017; 2: 29–37.
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10. Cheban A. Iu. Improving the technique and technology of blastless mining: monograph. Khabarovsk:
IM FEB RAS Publishing; 2017. (In Russ.)
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Received 19 August 2019
УДК 622.755:622.362.3 | DOI: 10.21440/0536-1028-2019-8-21-29 | Download |
Abstract
Introduction. For solid sand particles continuous separation by size and density in the proccessing chain of placer development with suction dredges, it is advisable to use cylindrical hydrocyclones when dredging a deposit.
Research aim is to determine process parameters of small and light particles and heavy minerals secondary separation in cylindrical hydrocyclones when developing placers with dredgers.
Methodology. The paper deals with the problems of throughput and structural dimensions determination and solid particles separation in fat bottom cylindrical hydrocyclones calculation based on the theoretical positions of cylindrical-conical hydrocyclones and laboratory experiments.
Results. The most acceptable analytical dependencies and formulae were selected for the approximate determination of the parameters: throughput (productivity) according to the formula of Modera and Dalstrom; pressure drops with Reynolds and Euler numbers; boundary grain size according to the detailed formula of A. I. Povarov. A laboratory installation of a fat bottom cylindrical hydrocyclone was mounted with characteristics similar to cylindrical hydrocyclones. A sufcient convergence of the calculated parameters with the indicators measured at the laboratory installation of a fat-bottom hydrocyclone is shown with a separation efciency of 54%.
Conclusions. The use of the secondary separation of minerals in cylindrical hydrocyclones will signifcantly increase the efciency of their further dressing.
Key words: dredger; cylindrical hydrocyclone; performance; pressure drop; boundary grain.
REFERENCES
Received 28 October 2019
УДК 622.831 | DOI: 10.21440/0536-1028-2019-8-30-37 | Download |
ABSTRACT
Introduction. In 2016–2017 the lower horizons of Kholbinsky mine showed harmful rock pressure manifestation in the shape of detachment and caving of rock blocks. There is a critical need to specify geomechanical conditions in the mine in order to estimate the hazard level of currently operating and new mine workings.
Methodology. In the course of the research, a complex of methods and techniques including laboratory experiments on strength and elastic properties of rocks; spatial and statistic analysis of rock jointing; analysis of the level of kern disking in the marginal massif of prospecting holes; in-situ measurement of natural stresses by the method of crack release by the method of IM UB RAS; engineering and mathematical calculations of technogenic stresses in design elements of geotechnologies by proprietary techniques; mathematical modelling by the finite element method; visual observations of mine workings baring stability level, etc.
Results. It has been stated that a massif of rocks of Kholbinskymine lower horizons is caregorized as “nonhazardous”. Mine workings and pillars are in the unstable state. Statistic forms of rock pressure manifestation have been recorded. In order to improve the stability of support systems design elements, a complex of engineering-technical measures is required, including: well-timed extraction floor and intervening pillars; block reserves extraction term reduction; switch to rockburst-safe systems with backfilling; excavation walls supporting with anchors, etc. A final Report on rockbust hazard and gasdynamic manifestations at Zun-Kholba goldmine has been worked out according to the results of the research (2017).
Key words: narrow and large gold lodes; stability; rockburst hazard; mine workings; pillars; physicalmechanical properties of rocks; natural and technogenic stresses.
REFERENCES
Received 12 July 2019
УДК 622.276 | DOI: 10.21440/0536-1028-2019-8-14-20 | Download |
Abstract
Research aim and objectives. The article highlights the development of the Caspian shelf, identifies prospects and options for further development of oil and gas production in the Caspian.
The aim of the work is to conduct a comprehensive assessment of the new technology of “smart completion”. To achieve the goal, the following tasks were solved: optimization of fluid inflow to the well and prevention of gas from the gas cap and bottom water breakthrough into the well; integrated monitoring and control of the reservoir zones in real time without additional downhole operations.
Research methodology. When drilling horizontal wells undersea, the task of geosteering comes to the fore. It required the integration of seismic data, reservoir tilt measurements, GTI and GIS data and was carried out in real drilling mode. The applied technique provided visualization of the reservoir structure, which allowed for geosteering in accordance with the strategic objectives of the field development. Detailed mapping of bed elements and fluid contacts in real time provides critical information in order to avoid going beyond the reservoir.
Research results and analysis. The inexpediency has been determined of operating with extended lengths of phase-by-phase zones of oil rims with active bottom water without well fluid inflow profiles control devices. This scheme allowed to optimize the profile of well fluid flow into the well, reducing the risks of water and gas premature breakthrough. The solution to this problem, namely the reduction in the volume of breakthrough gas and/or water into the borehole, is through active jointing of zones.
Summary. This complex allows real-time monitoring and control of reservoir zones in the reservoir without additional downhole operations. Thanks to this, the technologies of smart wells provide maximum drainage area of the reservoir and increase oil recovery of the reservoir. An assessment of the new technology of “smart completion” of production wells with long horizontal sections has been carried out.
Key words: shelf; Caspian sea; field; drilling of horizontal wells; geosteering; smart completion.
REFERENCES
Received 1 October 2019
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