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Determination of in situ stress state at Bukov Bukov URF II - search of the stress state measurement methods and study of their use in the process of construction and operation of a deep geological repository.
Vavro, Martin ; Waclawik, Petr ; Souček, Kamil ; Staš, Lubomír ; Koníček, Petr ; Jiránková, Eva ; Schuchová, Kristýna ; Kukutsch, Radovan ; Kajzar, Vlastimil
The presented search summarizes main measurement methods and their corresponding technical instrumentation, which were used in the past to determine the stress state of the rock\nmass, both in the conditions of Bukov URF I or the Rožná mine respectively, and especially in the environment of selected foreign underground research laboratories. The key results obtained during these stress measurements are also compiled. The findings are then reflected in the proposed method of rock mass stress measurement and monitoring in various stages of the process of preparing and operating a deep geological repository (DGR) in the Czech Republic. From the conducted search of the crucial published studies and the results of in situ experiments, it follows that the most commonly used methods of stress measurement worldwide are mainly hydraulic fracturing of borehole walls (hydrofracturing) and the overcoring method. These two methods were also proposed as the most suitable for the stage of selecting the final site of the DGR in the Czech Republic. In the phase of construction the DGR, it was recommended to extend them by the method of inverse analysis of convergence measurements. For the purposes of measuring stress changes during the construction and operation of the DGR, monitoring using conical tensometric CCBM probes was recommended as the most suitable.
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Geological and geotechnical characterisation of the mining environment - URF Bukov II - Interim report III
Soejono, I. ; Bukovská, Z. ; Rukavičková, L. ; Švagera, O. ; Chabr, T. ; Souček, Kamil ; Vavro, Martin ; Morávek, R. ; Levý, O. ; Sosna, K. ; Kryl, J. ; Řihošek, J. ; Zelinková, T. ; Dobeš, P. ; Hanák, J. ; Čermák, F. ; Kašpar, R. ; Mareček, L. ; Nedvěd, J. ; Vavro, Leona ; Myška, O. ; Janeček, Ivan
This report describes the work carried out in the third year of the public contract Geological and geotechnical characterisation of the rock environment – the Bukov URF II. The characterisation and descriptive works are directly related to the excavation of the premises for the future underground laboratory. These include in particular: geological and geotechnical documentation of the faces and walls of the workings, petrographic, mineralogical and structural geological documentation, hydrogeological characterisation of the environment, as well as determination of the physical and mechanical properties of the rock-mass in situ and in the laboratory, geophysical characterisation and monitoring of the seismic effects of blasting. The report also includes the newly developed rock mass\nclassification system and the results of its testing on the Bukov URF II site. The report includes also brief overview of the work planned for the following year of the project.
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Mechanical properties of basalt: a study on compressive loading at different strain rates using SHPB
Falta, J. ; Krčmářová, N. ; Fíla, T. ; Vavro, Martin ; Vavro, Leona
This article focuses on the mechanical properties of basalt in compressive loading at different strain-rates. The study employs advanced instrumentation for the evaluation of the results in dynamic conditions, while standard uni-axial loading device is used for evaluation in quasi-static conditions. Basalt specimens were subjected to four different loading-rates from 200–600 s−1 on which the stress-strain dependence was evaluated together with DIC analysis of crack initiation and disintegration process. Understanding the mechanical properties of basalt can provide insights for engineers and designers in creating structures that are durable and able to withstand different loading conditions. The findings of this study can have implications for a wide range of industries, including aerospace, automotive, and construction, among others.
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Interpretation of regional faults at the Carboniferous structural level and experiences with manifestation of stress in vicinity faults at the area of the power plant Dětmarovice
Waclawik, Petr ; Ptáček, Jiří ; Vavro, Martin
The expert assessment deals the interpretation of regional faults, the assessment of their possible recent activity and summary of experiences with manifestation of stress in vicinity faults during OKR mining activity at the level of the Carboniferous structural floor. The results of the assessment will be used to assess the possible tectonic influence of faults in the area of the power plant Dětmarovice, especially in connection with the geophysical works. The interpretation of regional faults is based on knowledge of the geological structure of the Carboniferous structural level and on the basis of experience with stress and deformation manifestations during the drivage of mine excavations. The expert evaluation take into consideration the structural-tectonic development and tectonic conditions of the basin, which are conditioned by the overall deformational development of the Variscan orogen. There are also the summary of available technical documents, which could be useful for the geological assessment of the underlying bed and the assessment of the possible effects of induced seismicity in the interest area of power plant Dětmarovice.
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Geological and geotechnical characterisation of the mining environment - URF Bukov II - Interim report II
Bukovská, Z. ; Rukavičková, L. ; Chabr, T. ; Morávek, R. ; Levý, O. ; Sosna, K. ; Souček, Kamil ; Vavro, Martin ; Zelinková, T. ; Dobeš, P. ; Švagera, O. ; Kryl, J. ; Soejono, I. ; Řihošek, J. ; Holeček, J. ; Hanák, J. ; Čermák, F. ; Kašpar, R. ; Mareček, L. ; Nedvěd, J. ; Vavro, Leona ; Waclawik, Petr ; Staš, Lubomír ; Myška, O.
This report describes the work carried out in the second year of the public contract Geological and geotechnical characterisation of the rock environment – PVP Bukov II. The\ncharacterisation and descriptive works are directly related to the excavation of the premises for the future underground laboratory. These include in particular: geological and geotechnical documentation of the faces and walls of the workings, petrographic, mineralogical and structural geological documentation, hydrogeological characterisation of the environment, as well as determination of the physical and mechanical properties of the rock mass in situ and in the laboratory, geophysical characterisation and monitoring of the seismic effects of blasting and hydrogeological monitoring. An important part of this report is preparation of the classification system used to describe the rock mass. The report also includes a brief overview of the work planned for the third year of the project.
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Research of geotechnical methods – Stage research report – Stage C
Staš, Lubomír ; Waclawik, Petr ; Souček, Kamil ; Vavro, Martin ; Kukutsch, Radovan ; Schuchová, Kristýna ; Gong, Libin ; Kubina, Lukáš ; Zajícová, Vendula ; Nohejl, Zdeněk ; Rutar, Tomáš
The main goal of project No. FV20294 (GEOSTAB) was the verification of measured geophysical quantities with data obtained by various geotechnical methods. For this reason, stage C - Research of geotechnical methods was solved in parallel and in close cooperation with stage B - Research of geophysical methods. The geotechnical experiments in situ were carried out in the same localities where geophysical methods were applied. For this purpose, several underground mining workings located in different lithological and geomechanical conditions were selected. Experimental gallery Josef was selected in volcanic rocks, the metamorphic rock mass was represented by underground workings of the former deep uranium mine Rožná and the sedimentary environment was examined in the old slate mine Modrá štola. The stage research report summarizes the results of geotechnical, laboratory and numerical methods from all the mentioned localities.
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Characterization of the Excavation Damage Zone (EDZ) in different geotechnical conditions
Staš, Lubomír ; Waclawik, Petr ; Souček, Kamil ; Vavro, Martin ; Zajícová, Vendula
In order to realize a comparative study of the Excavation Damage Zone (EDZ), two lithological and geotechnical different localities were selected. The first locality is located in the metamorphic rocks of the Rožná Mine. The second locality is located in the volcanic-sedimentary series of the Experimental gallery Josef. In order to evaluate the range of the EDZ, a combination of geotechnical and laboratory methods was used at the mentioned localities. The geotechnical method included the qualitative evaluation of the rock mass using the RQD index on the borehole core. The RQD index and failures of borehole walls were also determined based on OBI and ABI methods. In the laboratories, the pore space was characterized using X-ray computer micro-tomography (X-ray) and high-pressure porosimetry (MIP). The research report summarizes the results of these methods.
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