National Repository of Grey Literature 26 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Obtaining data from the deep horizons of the Rožná Mine
Bukovská, Z. ; Bohdálek, P. ; Buda, J. ; Dobeš, P. ; Filipský, D. ; Franěk, J. ; Havlová, V. ; Chabr, T. ; Knés, I. ; Kryl, J. ; Kříbek, B. ; Laufek, F. ; Leichmann, J. ; Navrátil, P. ; Pořádek, P. ; Rosendorf, T. ; Soejono, I. ; Sosna, K. ; Souček, Kamil ; Šustková, E. ; Švagera, O. ; Vavro, Leona ; Vavro, Martin ; Veselovský, F. ; Waclawik, Petr ; Zuna, M.
This report summarizes the work and partial results made under the Public Procurement Obtaining Data from the deep horizons of the Rožná Mine in the first phase of the third and fourth subdivisions from February to November 2018. These are in particular technical works (boreholes, access to corridors),seismic measurements, sampling for laboratory analysis (physical-mechanical properties of rocks, breakage fills, bearing revalidation), structural characterization of the rockanalytical work on all samples taken. Parallel to these works3D models are being prepared, especially data preparation for modeling.
Instrumentation of four-point bending test during 4D computed tomography
Kytýř, Daniel ; Fíla, Tomáš ; Koudelka_ml., Petr ; Kumpová, Ivana ; Vopálenský, Michal ; Vavro, Leona ; Vavro, Martin
High-resolution time-lapse micro-focus X-ray computed tomography is an effective method for investigation of deformation processes on volumetric basis including fracture propagation characteristics of non-homogeneous materials subjected to mechanical loading. This experimental method requires implementation of specifically designed loading devices to X-ray imaging setups. In case of bending tests, our background research showed that no commercial solution allowing for reliable investigation of so called fracture process zone in quasi-brittle materials is currently available. Thus, this paper is focused on description of recently developed in-situ four-point bending loading device and its instrumentation for testing of quasi-brittle materials. Proof of concept together with the pilot experiments were successfully performed in a CT scanner TORATOM. Based on results of the pilot experiments, we demonstrate that crack development and propagation in a quasi-brittle material can be successfully observed in 3D using high resolution 4D micro-CT under loading.
Effective crack model application for analysis of chevronnotched cylindrical specimens fracture response
Halfar, P. ; Frantík, P. ; Šimonová, H. ; Daněk, P. ; Keršner, Z. ; Vavro, Leona ; Vavro, Martin
This paper introduces the application of an effective crack model to analyse the response\nof chevron-notched cylindrical specimens loaded in three-point bending. There were\nanalysed the three sandstone specimens from the Javorka locality and three concrete\nspecimens from the building structure of the Ostrava-Vítkovice railway station. The\nchevroncylinder software based on the finite element method was used for the\ncalculations.
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.
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.
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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.
Bukov PVP underground research laboratory - geotechnical conditions of construction
Souček, Kamil ; Vavro, Martin ; Staš, Lubomír ; Koníček, Petr ; Ptáček, Jiří ; Waclawik, Petr ; Vavro, Leona ; Lednická, Markéta ; Kaláb, Zdeněk ; Šňupárek, Richard ; Vondrovic, L.
Bukov PVP Underground Research Laboratory (Bukov URL) is designed to be a test site for the evaluation of properties and behavior of the rock mass which is of similar type as selected candidate sites in the Czech Republic. It is situated at a depth corresponding to the proposed storage depth of the final locality for the national deep repository of high-level radioactive waste. The Bukov URL, the construction of which has begun in 2013, is situated in the southern part of the Rožná uranium deposit, at the northeastern periphery of the Strážek Moldanubicum close to its contact with the Svratka Unit. The rock mass is composed of relatively monotonous rock sequences primarily of a volcanosedimentary origin. They are currently represented, due to the subsequent tectonometa-morphic development, by migmatized biotite paragneisses up to stromatitic and/or oftalmitic migmatites, amphibole-biotite to biotite-amphibole gneisses, and amphibolites. The workings of the Bukov URL are situated on the level 12 of the Bukov-1 shaft, at the depth of about 600 m below the earth’s surface. The Bukov URL is still under construction and the research works by the consortium of several organizations – ÚJV Řež, a.s., Czech Geological Survey, Institute of Geonics of the CAS, v.v.i., and Arcadis CZ, a.s. - are carried out simultaneously. The research activities focus on a complex geological and geotechnical characterization of the rock mass of interest, which is vital for the realization of further research in situ. This paper briefly describes the technical solution of the Bukov URL and the process of its construction.
Geotechnické vyhodnocení průzkumných jádrových vrtů S-3 a S-4 na lokalitě PVP Bukov
Souček, Kamil ; Vavro, Martin ; Vavro, Leona ; Georgiovská, Lucie
Předmětem řešeného úkolu je geotechnické vyhodnocení průzkumných jádrových vrtů S-3 a S-4, včetně realizace jejich videoinspekce in situ. V rámci řešeného úkolu byly realizovány následující práce: - makropetrografický popis vrtného jádra, - upřesnění makropetrografického popisu hornin pomocí optické mikroskopie horninových výbrusů, zhotovených z vybraných horninových vzorků, - analýza RQD parametru, kusovitosti vrtného jádra a úklonu foliace k ose vrtu, - fotodokumentace vrtného jádra, - videoinspekce vrtů in situ. Výsledky a výstupy provedených prací jsou zpracovány v předkládané zprávě, jejíž členění odpovídá výše uvedenému rozsahu prací. Petrografické popisy hornin a grafické výstupy z provedených analýz a měření jsou, z důvodu řádné čitelnosti a přehlednosti, převážně zpracovány a prezentovány v samostatných přílohách této zprávy (viz Seznam příloh). Součástí zprávy jsou rovněž dva DVD disky, na kterých jsou nahrány jak soubory obsahující datový záznam z videoinspekce obou vrtů ve formátu "*.mpg", tak text zprávy včetně jednotlivých příloh v pdf formátu.
Mineralogical and silicate analysis of steel work waste samples after expansibility and disintegration tests
Martinec, Petr ; Ščučka, Jiří ; Kubina, Lukáš ; Vavro, Leona
The report includes results of mineralogical and petrographic analyses of material samples of steel work waste after expansibility and disintegration tests.
Determination of physico-mechanical and geotechnical properties of rocks - a sample taken from initial blasting of connecting crosscut BZ-XIIJ
Souček, Kamil ; Vavro, Martin ; Vavro, Leona ; Georgiovská, Lucie
Macroscopic description, microscopic analysis and results of assessment of physico-mechanical and geotechnical properties of a rock sample taken from initial blasting of connecting crosscut BZ-XIIJ are presented in the research report. The crosscut BZ-XIIJ is driven for the purpose of construction of the underground research laboratory (URL) Bukov.

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