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Authentication of real rock mass field voltage to increase safety in anomalous stress states
Koníček, Petr ; Staš, Lubomír ; Ptáček, Jiří ; Kaláb, Tomáš ; Chura, Jan ; Souček, Kamil ; Waclawik, Petr
Voltage fields are one of the key factors that, decisively, along with the mechanical and remodeling properties of rocks, greatly influence the behavior of the mountain massif. Knowledge of stress fields is beneficial for the design and successful implementation of geotechnical underground projects (eg for the assessment of the stability of underground spaces, the behavior of proposed reinforcements of underground structures, for space-time placement of underground structures) especially in non-trivial geomechanical conditions, both in terms of natural factors affecting stress fields structural and geological structure of the rock mass, tectonic stress, cracks and discontinuity in the rock mass) as well as anthropogenic factors (geomechanical configuration of the underground spaces and dynamics of their changes). Geotechnical practice in our (Czech) conditions is usually used only calculations of a voltage field based primarily on the theoretical behavior of the rocks and the assumed vertical geostatic pressure at a given depth. The development of possible progressive deformations of the stress field is then derived from the development of anthropogenic interventions into a relatively homogeneous massif. In fact, tension is also affected by close geological structures. The data obtained from the study of the magnitude, direction and change of stress in the mountain massif are a significant contribution in mathematical modeling where they can be used as input parameters to obtain a more accurate picture of the behavior of mountain massifs and underground structures in the subject areas.
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Obtaining data from the deep horizons of the Rožná mine - realization project of work
Švagera, O. ; Bukovská, Z. ; Souček, Kamil ; Vavro, Martin ; Waclawik, Petr ; Sosna, K. ; Havlová, V. ; Zuna, M. ; Jankovský, F. ; Filipský, D. ; Chabr, T. ; Navrátil, P. ; Mixa, P. ; Soejono, I. ; Laufek, F. ; Kříbek, B. ; Leichmann, J. ; Zeman, J.
Realization project summarizes the planned work, its progress and continuity within the environment of Rožná I mine in the extent of the procurement „Získání dat z hlubokých horizontů dolu Rožná“ which is being compiled by Hluboké hluboké horizonty Rožná group. The final goal is to clarify the significance and spatial influence of major tectonic fault on surrounding rock mass. The results will help to clarify localization and safety issues of the potential deep underground repository, especially with respect to the Kraví hora locality.
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Final research report to the project PB-2014-ZL-U2301-004-BUKOV
Souček, Kamil ; Vavro, Martin ; Staš, Lubomír ; Kaláb, Zdeněk ; Koníček, Petr ; Georgiovská, Lucie ; Kaláb, Tomáš ; Konečný, Pavel ; Kolcun, Alexej ; Králová, Lucie ; Kubina, Lukáš ; Lednická, Markéta ; Malík, Josef ; Martinec, Petr ; Ptáček, Jiří ; Vavro, Leona ; Waclawik, Petr ; Zajícová, Vendula
Bukov Underground Research Facility (Bukov URF) has been built as a test site to assess the properties and behaviour of the rock mass analogous to selected candidate sites. It is situated at a depth corresponding to the proposed storage depth of the final locality for the Czech Republic´s deep repository of high-level radioactive waste. Bukov URF is located in the Vysočina Region, the cadastral district of Bukov, approx. 3 km south-eastwards from the municipality of Dolní Rožínka. The underground research facility is placed approx. 300 m from the Bukov-1 shaft, namely on the level 12 of the shaft, at the depth of about 550 – 600 meters below the Earth’s surface. As for the regional geology, Bukov URF is found at the southern part of the Rožná uranium deposit, at the north-eastern edge of the Strážek Moldanubicum close to its contact with the Svratka Unit. The rock mass is composed of a relatively monotonous sequence of differently migmatized biotite gneisses to stromatic migmatites, continuing with amphibole-biotite to biotite-amphibole gneisses and amphiboles, with occasional fine intercalations of aplites, pegmatites or calc-silicate rocks (erlanes). Between 2013 and 2017 and within the complex geotechnical characterization of the Bukov URF, the Institute of Geonics of the Czech Academy of Sciences (Ústav geoniky AV ČR, v.v.i.) in Ostrava carried out a series of laboratory and field works in order to provide a detailed description of the geotechnical and geomechanical properties and quality of the rock mass. The works included the determination and assessment of the physical-mechanical properties of the rocks sampled from the walls, boreholes and ground surface in the locality, the determination of stress state and deformation properties of the rock mass using the methods of hydrofracturing of borehole walls, Goodman Jack and CCBO, or CCBM, determination of the rock mass quality based on selected index geomechanical properties, periodic, long-term strain-gauge measurements and convergence measurements, and the assessment of the effect of technical and mine-induced seismicity on the rock mass of interest. The implemented set of research works was supposed to render a sufficient and integral whole of geotechnical and geomechanical knowledge vital for the subsequent implementation of extensive research experiments focused on long-term safety and technical feasibility of the future national deep repository of radioactive waste.
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Velocity measurements on continuous micro water jet using fluorescent PMMA seeding particles
Zeleňák, Michal ; Ščučka, Jiří ; Souček, Kamil
The paper deals with application of optical diagnostic techniques for velocity\nmeasurements of continuous micro water jet. The combination of Particle image\nvelocimetry, Particle tracking velocimetry, Laser induced fluorescence and\nShadowgraphy methods have been applied together with the use of fluorescent\nPMMA seeding particles. An experimental closed water circuit was designed with\na low-pressure water pump, and a series of experiments was conducted to\nmeasure the velocity of seeding particles in the water jet flow below the diamond\nmicro-nozzle outlet. The basic principles of the methods used in experiments are\nalso described.
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Underground research site Bukov - geotechnical characterization of the site
Souček, Kamil ; Vavro, Martin ; Vavro, Leona ; Staš, Lubomír ; Georgiovská, Lucie
Podzemní výzkumné pracoviště Bukov (PVP) je navrženo jako testovací lokalita pro zhodnocení vlastností a chování horninového masivu, typově blízkého vybraným kandidátním lokalitám, v hloubce odpovídající předpokládané úložné hloubce finálního hlubinného úložiště vysoce aktivních odpadů v České republice. PVP Bukov, jehož výstavba byla zahájena v roce 2013, je realizováno v jižním křídle uranového ložiska Rožná, na severovýchodním okraji strážeckého moldanubika, poblíž jeho styku se svrateckým krystalinikem. Důlní díla pracoviště jsou situována na 12. patře jámy Bukov-1, v hloubce přibližně 600m pod povrchem.
Fulltext: content.csg -  PDF
Plný tet: UGN_0465530 - PDF
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Partial Report IV / 2016 - Rating of the deformation stress monitoring the state of the rock mass during mining coal seam 30 (634) within the trial operation of mining method corridor - a pillar in OPJ ČSM - NORTH
Waclawik, Petr ; Ptáček, Jiří ; Kukutsch, Radovan ; Kajzar, Vlastimil ; Koníček, Petr ; Souček, Kamil ; Staš, Lubomír
Monitoring of the deformation stress state of the rock mass is a prerequisite for the verification of unapproved new mining methods hall-pillar and its further application in the Czech part of the Upper Silesian coal basin. This mining method is designed on the basis of experiences and practices that are verified in different natural conditions and depths below the surface and is therefore essential for the verification of conditions for the Czech part of the Upper Silesian Basin based on geotechnical monitoring. The present report is prepared on the basis of a contract no. 942/50/10, where the Institute of Geonics, v.v agrees to make periodic evaluation of monitoring data napěťodeformačního state of the rock mass. In accordance with the aforementioned agreement, the message is processed in the six-month period and continues in the interim report III / 2015 (Waclawik et al. 2015) passed buyers in April this year. Interim results of the geotechnical monitoring, such as the experience gained during the first conquest dobývky V show specifics of natural conditions in trial operation unapproved new mining methods hall-pillar.
Fulltext: content.csg - PDF
Plný tet: UGN_0464907 - PDF
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Summary of foreign knowledge about the origin and development of EDZ in crystalline rocks - research
Vavro, Martin ; Souček, Kamil ; Staš, Lubomír ; Vavro, Leona
Presented search summarizes findings of foreign research oriented on the origin and evolution of the excavation damaged zone in crystalline rocks with a particular focus on the essential results of experimental projects which were performed in Canada, Sweden, Finland, and Switzerland. The study is divided, excluding the introduction, into seven main chapters of the text, which gradually deal with: (1) definition of key terms, (2) overview of the main underground research laboratories in the world where EDZ assessment was conducted, (3) methods suitable for EDZ description and characterization, (4) main factors influencing the origin of failure around the excavations and time-dependent evolution of EDZ. An overview of important outcomes of EDZ experiments, focusing on the European hard rock laboratories (Stripa, Äspö, Onkalo/Olkiluoto and Grimsel), and their summary are presented in the final two chapters.\nThe review summarizing the published key findings and results of in situ experiments shows, that for rock in lower stress state, i.e. in no spalling environment, the extent and character of rock mass damage is typically dependent on the excavation method. Using mechanical excavation, rock damage zone with thickness less than 3 centimeters can be originated. The microcracks within this zone contribute to the increase of hydraulic conductivity of the rock mass. At some test sites (Äspö, Grimsel), where the tunnel boring machine technology was used, the damage zone was already detected in depth of less than 5 mm.\nOn the contrary, openings excavated by drilling and blasting are characterized by much more extensive damage zones up to several tens of centimeters in width. The damage progressively diminishes with the distance from the opening.
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