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Determination of the initial stress tensor from deformation of underground opening-theoretical background and applications
Malík, Josef ; Kolcun, Alexej
In this paper a method for the detection of initial stress tensor is proposed. The method is based on measuring distances between some pairs of points located on the wall of underground opening in the excavation process. This methods is based on the solution of eighteen auxiliary problems in the theory of elasticity with force boundary conditions. The optimal location of the pairs of points on the wall of underground work is studied. The pairs must be located so that the condition number of a certain matrix has the minimal value, which guarantees a reliable estimation of initial stress tensor.
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Comprehensive geological characterization of URF Bukov – part II Geotechnical characterization.
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
This final report was processed as a part of Radioactive Waste Repository Authority project Research support for safety evaluation of the deep repository, which is a part of the preparation for the deep repository of nuclear waste (further DR). The aims of the project were collection and interpretation of geological data, the creation of models and obtaining information necessary for evaluation of potential sites for DR emplacement regarding long-term safety. On the basis of public submitting act, a 4-year contract was signed with ÚJV Řež, a.s. and its subcontractors: Czech Geological Survey, Czech Technical University in Prague, Technical University in Liberec, Institute of Geonics of Czech Academy of Sciences, and companies Arcadis CZ, Progeo, Chemcomex Praha and Centre for Research Řež about providing research support for evaluation of long-term safety.
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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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Reference points distance measurement
Jedlička, Petr ; Čížek, Martin ; Staš, Lubomír ; Malík, Josef
The device is developed for measuring the deformation of natural and artificial underground spaces, especially active mines. The deformations are derived from LIDAR distance measurements of network of reference points. Each reference point consists of steel rod embedded into wall and stainless steel ball as reflector. The LIDAR is placed in a precision adjustable 2-axis mount and which can be fitted to any reference point. The system is portable, battery powered. Part of the system is software allowing reading and processing LIDAR measurement data. The measurement is usually started immediately after excavation, and then go on as long-term monitoring after the completion of the construction or mining activities.
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Stability of suspension bridges in lateral wind
Malík, Josef
The collapse of the original Tacoma suspension bridge has been studied in many papers. On 7 November 1940 around 10 a.m. the torsional oscillations appeared on the deck of the original Tacoma bridge after the loosening of one midspan cable band, which resulted in the lateral asymmetry of the construction. It seems that the loosening of the midspan cable band had a significant impact on the behavior of the bridge and in the end it resulted in the collapse.
Fulltext: content.csg -  PDF
Plný tet: UGN_0425332 - PDF
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Mathematical modelling of geosynthetic tubes
Malík, Josef
Geosynthetic tubes are comprised of thin sheets and pumped with water or slurry. The tubes are made of synthetic fabrics (geotextile). They have been used as dikes or breakwaters and to prevent beach erosion. They have many other applications in geoengineering.
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2D-analýza geotextilních trubic
Malík, Josef
The analysis describing both stress and geometry of geosynthetic tubes is presented. The parametric study shows that the most critical point responsible for stability is pumping pressure. A small pressure increase can result in a big increase or tension force in geosynthetic. On the other hand it has small infuence on volume capacity.
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