НАУЧНИ ПУБЛИКАЦИИ Archives - Page 3 of 35

DEVELOPMENT OF THE MINING INDUSTRY IN BULGARIA IN THE PERIOD 1990 - 2020: AN OVERVIEW

Prof. Phd Nikolay Sterev, Assoc. Prof. Vyara Milusheva, Assoc. Prof. Petya Biolcheva, Assoc. Prof. Ivaylo Ivanov, Assoc. Prof. Marin Geshkov

ABSTRACT

The mining industry is often underestimated both in terms of its contribution to the economy and its development prospects. However, mining and the mining industry have been the basis of the growth of the Bulgarian economy for more than 60 years, and especially the mining industry has been a key factor in the development of the economy in transition - for the last 30 years. Regardless of the pronounced dependence of the mining industry on the economic development, it can be defined as one of the sectors that are leading in terms of: introduction of new technologies; wage growth; fulfilment of the requirements for labour safety and environmental protection; introducing the requirements of the circular economy and the rules of corporate social responsibility (CSR). This article reveals the answers to the question: how is the mining industry changing from within to meet these contemporary economic, social and political challenges. The presented analysis objectively analyses data from the development of the sector from 1989 to 2019, incl. in terms of production, investment, labour and wages, etc. On this basis, the necessary summaries are made and trends in the development of this sector are outlined.

KEYWORDS

mining industry, Bulgaria, industry growth and development

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DEVELOPMENT OF THE MINING INDUSTRY IN BULGARIA IN THE PERIOD 1990 - 2020: AN OVERVIEW

REFERENCES

1. Avtorski kolektiv (Lyuben Berov i Dimitar Dimitrov – red.), Razvitie na industriyata v Bulgaria, izd. Nauka i izkustvo, S., 1990 g.
2. Shterev N. i kolektiv. Razvitie na industriyata v Bulgaria sled 1989 g.: ikonomicheski, sotsialni i politicheski efekti, UI Stopanstvo – UNSS, 2023.
3. NSI, http/www.nsi.bg

RESEARCH OF THE DEFORMATION STATE OF THE ROCK MASSIVE FOR PRESERVATION PURPOSES TO UNDERGROUND AND OVER-GROUND OBJECTS AT UNDERGROUND DEVELOPMENT OF ORE DEPOSITS FOR THE CONDITION OF “GORUBSO – MADAN” Ltd

Еng. Desislava Atanasova - Venkova

ABSTRACT

The changes in the deformation state of the massive, due to the development of mining works, lead to the need to study and control the deformation processes and protect various underground and surface objects from their influence. In the sections „Varba“ and „Krushev dol“, of „Gorubso-Madan“, with the advancement and penetration of the mine workings, preconditions are created for relocations of the surface, as well as of the rock massif. The used chambers are large in size and the conducted operation, close to capital works, creates a need for observations and analysis of the condition of the massif and the surface facilities. The report presents the observation stations built in the above-mentioned sections. Initial surveying observations have been made, the results of which will be used for comparison with subsequent measurements. Based on the data for realized spatial displacements of the observed landmarks on the earth‘s surface and in the underground workings, the deformation state of the massif at different moments of the observations will be determined.

KEYWORDS

massive, deformation state, initial surveying observations

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RESEARCH OF THE DEFORMATION STATE OF THE ROCK MASSIVE FOR PRESERVATION PURPOSES TO UNDERGROUND AND OVER-GROUND OBJECTS AT UNDERGROUND DEVELOPMENT OF ORE DEPOSITS FOR THE CONDITION OF “GORUBSO – MADAN” Ltd

REFERENCES

1. Varbanov, V., Izsledvane vliyanieto na podzemnite minni raboti za deformirane na vertikalni shahti, Sofia. 1976.
2. Instruktsia za izsledvane na deformatsiite na sgradi i saorazhenia, chrez geodezicheski metodi, Komitet po arhitektura i blagoustroystvo- Glavno upravlenie po geodezia, kartografia i kadastar, 1980.
3. Turchaninov, I.A., M.A.Yofis, Э.V.Kasparyan, Osnovы mehaniki gornыh porod, Leningrad, Nedra, 1989.
4. Hrischev, G., Opazvane na saorazheniyata i obektite ot vrednoto vliyanie na podzemnite minni raboti, „Tehnika”, Sofia, 1978.
5. Tsonkov, Al., M.Begnovcka, Cledene yctoychivoctta na ckalnia maciv chpez mapkshaydepcki izmepvania ppi dobiv na olovno-tsinkova pyda za ycloviyata na p-k „Kpyshev dol”, „GORUBSO – MADAN” AD, VIII Mezhdynapodna konfepentsia po geomexanika, 2-6 yuli, Bapna, 2018 g.
6. Tsonkov, Al., M. Begnovcka, S. Paytalov, Pezultati i analiz na ekcpepimentalni izcledvania chpez mapkshaydepcki izmepvania za cledene uctoychivoctta na ctenata na Xvoctoxpanilishte „Laki – 2 vremenno” kam „Laki Invect“ AD, IX Mezhdynapodna konfepentsia po geomexanika, 7-11 septemvri, Bapna, 2020 g.

INFLUENCE OF SOIL LIQUEFACTION AND LOCAL GEOLOGICAL CONDITIONS ON EARTHQUAKE DAMAGES IN TURKEY ON 06.02.2023 – PART 1

PhD Eng. Nikolay Milev, Eng. Juan José Briones Contreras

ABSTRACT

The first part of the report presents the members of the team, the places visited, the different types of research and the main goals of the research. The geological and topographic features of the visited areas are considered: banked ground, Idil collapse, Islahiye and Tepehan landslides and the fault in two locations - Chigli and Islahiye, and the damage caused by the earthquake are described. Particular attention is paid to the coastal city of Iskenderun (in part 1) and the city of Golbasi (in part 2), where a number of significant damages were revealed due to the influence of the ground base and the natural frequency of the soil massive was determined. The second part analyzes the reasons for the completely destroyed buildings in the cities of Antakya and Kahramanmarash.

KEYWORDS

liquefaction, earthquake, geotechnics, soil dynamics, Turkey

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INFLUENCE OF SOIL LIQUEFACTION AND LOCAL GEOLOGICAL CONDITIONS ON EARTHQUAKE DAMAGES IN TURKEY ON 06.02.2023 – PART 1

REFERENCES

1. Middle East Technical University. Preliminary Reconnaissance Report on February 6, 2023, Pazarcık Mw=7.7 and Elbistan Mw=7.6, Kahramanmaraş-Türkiye Earthquakes February 20, 2023. https://eerc.metu.edu.tr/en/system/files/documents/DMAM_Report_2023_Kahramanmaras-Pazarcik_and_Elbistan_Earthquakes_Report_final_ENG.pdf
2. Earthquake Engineering Research Institute, Geotechnical Extreme Events Reconnaissance Association. “February 6, 2023 Türkiye Earth-quakes: Report on Geoscience and Engineering Impacts”. https://learningfromearthquakes.org/ images/2023_02_06_nurdagi_turkey/GEER_2023_Turkey_Earthquake_FullReport_ReducedSize.pdf
3. Уеб семинари, организирани от Earthquake Engineering Research Institute. https://www.eeri.org/what-we-offer/webinars/16272-lfe-kahramanmaras-earthquakesreconnaissance-webinar-series
4. Turkey Accelerometric Database and Analysis System (TADAS) – https://tadas.afad.gov.tr/
5. Rojay, Bora, Ariel Heimann & Vedat Toprak (2001). Neotectonic and volcanic characteristics of the Karasu fault zone (Anatolia, Turkey): The transition zone between the Dead Sea transform and the East Anatolian fault zone, Geodinamica Acta, 14:1-3, 197-212, DOI: 10.1080/09853111.2001.11432444.
6. Özşahin, E. (2010). Antakya’da hatay yer seçiminin jeomorfolojik özellikler ve doğal risk açisindan değerlendirilmesİ. Balıkesir Üniversitesi Sosyal Bilimler Enstitüsü Dergisi , 13 (23) , 1-16 . Retrieved from https://dergipark.org.tr/tr/pub/baunsobed/issue/50236/647964
7. Özmen, Özgür Tuna et al. Microtremor Array Measurements for ShallowS-Wave Profiles at Strong-Motion Stations in Hatay and Kahramanmaras Provinces, Southern Turkey. Bulletin of the Seismological Society of America (2017),107(1): 445. https://doi.org/10.1785/0120160218
8. Ermini, L., Casagli, N., 2002. Criteria for a preliminary assessment of landslide dam evolution. In: Rybar, J., Stemberk, J., Wagner, P. (Eds.), Landslides. Proceedings 1st European Conference on Landslides 24–26 June 2002. Balkema, Prague, pp. 157–162.
9. Seed, H.B. and Idriss, I.M. (1971) Simplified Procedure for Evaluating Soil Liquefaction Potential. Journal of the Soil Mechanics and Foundations Division, ASCE 97, SM9, 1249-1273.
10. Idriss, I. M., and Boulanger, R. W. (2010). „SPT-based liquefaction triggering procedures.“ Report UCD/CGM-10/02, Department of Civil and Environmental Engineering, University of Cal Shear-wave velocity-based probabilistic and deterministic assessment of seismic soil liquefaction potential
11. Boulanger, R.W., and Idriss, I.M., (2014). CPT and SPT based liquefaction triggering procedures. Report No.UCD/CGM-14/01, Centre for Geotechnical Modelling, Department of Civil and Environmental Engineering, University of California, Davis, CA, 2 pp.
12. Kayen, Robert & Moss, R. & Thompson, Eric & Seed, Raymond & Cetin, Kemal & Der Kiureghian, Armen & Tanaka, Yasuo & Tokimatsu, Kohji. (2013). J.29 Shear-wave velocity-based probabilistic and deterministic assessment of seismic soil liquefaction potential. Journal of Geotechnical and Geoenvironmental Engineering. 139. 407-419. 10.1061/(ASCE)GT.1943-5606.0000743.
13. Wu J, Seed RB, Pestana JM (2003). Liquefaction triggering and post liquefaction deformations of Monterey 0/30 sand under uni-directional cyclic simple shear loading. Geotechnical Engineering Research report no. UCB/GE-2003/01, University of California, Berkeley, CA

ОТ ГЕОДИНАМИКАТА ДО ПОВЪРХНОСТНИТЕ ЛАНДШАФТИ И ТЯХНОТО ПОЛЗВАНЕ ОТ ЧОВЕЧЕСТВОТО

Венелин Велев

ABSTRACT

KEYWORDS

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ОТ ГЕОДИНАМИКАТА ДО ПОВЪРХНОСТНИТЕ ЛАНДШАФТИ И ТЯХНОТО ПОЛЗВАНЕ ОТ ЧОВЕЧЕСТВОТО

REFERENCES

1. Scar, S., V. M. Kawood, J. Chowdhtary, 2023. The day The Earth moved . – Reuters.com/graphics/turkey – quake/rupturegdpzqdzwwvw/
2. Черский, В. Н., Царев, В. П., Сороко, Т.И., Кузнецов, Е. В., 1985. Влияние тектоно-сейсмических процессов на образование и накопление углеводородов. – Новосибирск, „Наука“,
224 с.
3. Велев,В. Х., 2021. Неотектоника в югозападната част на Мизийската платформа с последствия за петролната геология на България. – Минно дело и геология, 2, 37-46.

MODELLING OF FIXED FIREFIGHTING SYSTEMS WITH LOW PRESSURE WATER MIST NOZZLES

Еng. vladislav stoykov, vlado_Prof. DSc. Eng. mihail mihaylov

ABSTRACT

The present works is related to the idea of researching and modeling stationary low pressure water fixed firefighting systems (FFFS) for fire protection of road tunnels with water mist. The GW M5 is tested, which is a compact, low pressure water mist nozzle specifically designed for overall and local use for protective water mist fire extinguishing systems. The main purpose of water mist systems is to prevent the full development of a fire in a road tunnel to its maximum capacity and, if possible, to ensure that damaged cars in a tunnel pipe can be separated from the rest of the passenger traffic, to localize and limit the spread of a possible fire inside a broken car. The operation of these FFFS will ensure the problem-free movement of other road users in the tunnel and also prevent the fire from spreading to other vehicles. Water mist systems are inherently effective in the early stages of fire development.

KEYWORDS

fires in road tunnels; fixed firefighting systems (FFFS); water mist - classes and characteristics; low pressure water mist nozzle; stand for testing nozzles

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MODELLING OF FIXED FIREFIGHTING SYSTEMS WITH LOW PRESSURE WATER MIST NOZZLES

REFERENCES

1. Fire Protection of high-rise Buildings with Water Mist. UC LGN 23, June 2018, www.LocalGov.co.uc
2. EN14972-1:2020 The European watermist standard. Implementation date 30-th June 2021.
3. BDS EN 14972-1:2021. Statsionarni pozharogasitelni instalatsii. Instalatsii s vodna magla. Chast 1: Proektirane, montirane, kontrolirane i poddrazhka, publ.19.05.2021 g.
4. BDS EN 14972-3:2022. Statsionarni pozharogasitelni instalatsii. Instalatsii s vodna magla. Chast 3: Protokol ot izpitvane na sistemi s avtomatichni dyuzi za ofisi, uchilishtni klasni stai i hoteli, 20.01.2022 g.
5. DIRECTIVE 2004/54/EC on minimum safety requirements for tunnels in the trans-European road network, 18.7.2004.
6. GW Sprinkler A/S Kastanievej 15 DK-5620 Glamsbjerg Denmark CVR/VAT No: 31 79 65 12.
7. NFPA 750 Standard on Water Mist Fire Protection Systems, 2019.
8. NFPA 25 Standard on sprinkler inspection forms.
9. GW Sprinkler A/S SN010 1001D GW M5.
10. Antonov, I.S. Prilozhna mehanika na fluidite. S., 2009, 2016.
11. FFFS-EVS for Highway Tunnels – Literature Survey and Synthesis, January 2020. Доклад № FHWA-HIF-20-016.
12. PIARC, Fixed Fire Fighting Systems in Road Tunnels: Current Practices and Recommendations. Permanent International Association of Road Congresses, Technical Committee on Road Tunnel Operation, 3.3, 2016.
13. Mihaylov, M., D. Makedonska. Izsledavne na dyuzi za pozharogasene s fino razprasnata voda v patni tuneli, toplotehnika, Godina H, Kniga 1, 2019, ISSN 1314-2550.

RISK ASSESSMENTIN THE MANAGEMENT OF MINING INVESTMENT PROJECTS USING THE RISK DISCOUNT FACTOR METHOD

Eng. Dimitar Shaykov

ABSTRACT

This article aims to clarify the process of risk management in mining investment projects, which is current due to its importance for the future profitability and efficiency of the investment activity. The future results of the investment activity in the mining industry are significantly influenced both by the shocks in the economic policy of the countries and by the numerous factors of the external and internal investment environment. A large part of them do not directly depend on economic subjects, and economic phenomena and processes are also under the influence of a large number of external factors to the investor. Economic evaluation and risk analysis are basic elements in the analysis of investment projects in the mining industry. In them, the importance of risk is determined by the need to carry out the most accurate risk assessment and incorporate the individual types of risk when determining the risk discount rate with which the expected net annual cash flows of the investment projects are discounted (updated). This leads to the determination of a risk discount rate that reflects the expected future profitability of the projects implemented by the investor. The determination of the risk discount rate is based on the risk discount factor method, also known as the risk accumulation method. On this basis, the investor can really assess the attractiveness of the investment projects

KEYWORDS

risk assessment, economic assessment, mining investment projects, risk discount factor

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RISK ASSESSMENTIN THE MANAGEMENT OF MINING INVESTMENT PROJECTS USING THE RISK DISCOUNT FACTOR METHOD

REFERENCES

1. Mitev, V. Metodika za ikonomicheska otsenka na vazmozhnostite za efektivno razrabotvane na novi nahodishta. І. Sashtnost na razrabotenata metodika. Sp. „Minno delo i geologia”, br. 1, 2005, s. 19-22.
2. Mitev, V. Metodika za ikonomicheska otsenka na vazmozhnostite za efektivno razrabotvane na novi nahodishta. ІІ. Rezultati ot prilozhenieto na metodikata v realni uslovia. Sp. „Minno delo i geologia”, br. 2/2005, s. 13-18.
3. Brankova, B., P. Zlatanov. Analiz na riska pri ikonomicheskata otsenka na minnite investitsii. Godishnik na Minno-geolozhkia universitet „Sv. Ivan Rilski“, tom 44, svitak IV, „Humanitarni i stopanski nauki“, 2003, s. 35-39.
4. Mitev, V. Otsenka na zapasite i resursite na nahodishtata na polimetalni rudi. Godishnik na MGU „Sv. Iv. Rilski”, t. 50, sv. ІV, „Humanitarni i stopanski nauki“, 2007, s. 53-58.
5. Radev, J. Economic analysis of investment projects in mining industry. Annual of University of Mining and geology “St. Ivan Rilski”, vol. 46, part ІV, “Humanitarian and Economic Sciences”, 2003, рр.49-54.
6. Mitev, V. Vidove risk i metodi za otsenka na riska pri investitsionnite proekti v minnia otrasal. Godishnik na MGU „Sv. Iv. Rilski”, t. 47, sv. ІV „Humanitarni i stopanski nauki“, 2004, s. 49-53.
7. Mitev, V. Klasifikatsia na metodite za otsenka na investitsionni proekti v minnia otrasal. Godishnik na MGU „Sv. Iv. Rilski”, t. 46, sv. ІV, „Humanitarni i stopanski nauki“, 2003, s. 55-60.
8. Mitev, V. Management of the quantity and quality of the reserves and resources of ore deposits. Journal of Mining and Geological Sciences, Vol. 62, Number 4, 2019, p. 09-14.
9. Yordanov, M. Otsenka na nahodishtata na etap Pre-feasiility study i Feasibility study s analiz na parichnite pototsi, I chast – Osnovni termini i ponyatia. Sp. „Minno delo i geologia“, br. 1/1998.
9. Yordanov, M. Otsenka na nahodishtata na etap Pre-feasiility study i Feasibility study s analiz na parichnite pototsi, I chast – Osnovni termini i ponyatia. Sp. „Minno delo i geologia“, br. 1/1998.