The aim of this paper is to show time-de pendent baseline variation between GPS stations situated in South-East Poland. This study was based on daily data analysis of selected GPS stations: WROC, GOPE, MOPI, KRAW and KATO. The start date o f the analysis is linked at every station with the beginning of its operation and the closing date of the operation is in 2006. The multiresolution signal decomposition method has been used to analyze the periodic terms of the time series of the above. The estimated trends enable further coordinate analysis as well as determination of site displacements at the study area., Mariusz Figurski, Krzysztof Kroszczyński, Paweł Kamiński and Marcin Gałuszkiewicz., and Obsahuje bibliografické odkazy
Monitoring of tectonic movements along three active faults of Dinaric (NW-SE trending) fault system in W Slovenia using TM 71 extensiometers was set up in 2004. After two and a half years of measurements clear trends of displacement were recorded. The average left-lateral displacement along a crack in the inner fault zone of the Idrija fault in Učja valley was reading 0.38 mm/year. Short term (10 months) rates were even greater and reached the value of 0.54 mm/year. Since the Idrija fault is considered generally to be dextral strike-slipping, the observed left-lateral displacement can be explained by variations in principle stress. Raša fault monitoring site at the foot of Vremščica Mt. established an average reverse uplift of hanging wall (SW) block of 0.24 mm/year and left-lateral displacement of 0.16 mm/year. Short term (9 months) vertical displacements reached the value of 0.53 mm/year. The inclined displacement is in agreement with geological and seismological observations. In the Postojna cave system two instruments were installed at the fault which extends parallely to Predjama fault zone. The average vertical displacement rate at Postojna 1 site was 0.01 mm/year. Both devices recorded similar reaction which can be attributed to 12 July, 2004 (Mw=5.2) earthquake with an epicentre 70 km away from the measuring site. Since there were no other stronger earthquakes in the vicinity and time span of monitoring, no other correlations were established with earthquake activity. The observed displacement rates along all three monitored faults of up to 0.5 mm/year are consistent with the regional deformation rate in W Slovenia established from GPS measurements which is of the order of 2 mm/year., Andrej Gosar, Stanka Šebela, Blahoslav Košťák and Josef Stemberk., and Obsahuje bibliografii
Considerable amount of waste in the form of polyethylene terephthalate (PET) bottles could be utilized in the form of dispersed microreinforcement in concrete. PET fibres, however, have poor wettability and adhesion to cement paste, which can be modified by alkaline hydrolysis with sodium hydroxide at elevated temperature. The alkaline treatment was used to increase fibre surface, which was followed by changes in the structure of the interfacial transition zone (ITZ) and interfacial bond between fibre and cementitious matrix. Raman microspectroscopy mapping was employed to study microstructural changes of ITZ within the distance 0 - 250 μm from a PET fibre. The band at 357 cm-1 corresponding to the Ca-O bond vibration in portlandite was used to determine its distribution. For determination of the relative abundance of ettringite, the SO42- stretching vibration at 987 cm-1 was used. The most intensive bands of portlandite and ettringite were found within the distance 0 - 50 μm from an unmodified PET fibre. Besides the elevated concentration of these minerals, abundant pores occur in this region. In the case of alkaline modified PET fibres the ITZ zone was not found., Vladimír Machovič, Ladislav Lapčák, Lenka Borecká, Miloslav Lhotka, Jana Andertová, Lubomír Kopecký and Linda Mišková., and Obsahuje bibliografii
Microscopic techniques, such as polarising microscopy and scanning electron microscopy with energy dispersive spectrometer (SEM/EDS), were used in combination with petrographic image analysis with the aim of a quantitative determination of the mineral composition, rock microstructure, and degree of metamorphism of selected quartz-rich metamorphic rock types. Sampled orthogneiss rock types are mainly composed of feldspar, quartz, biotite, and amphibole. The grains are less isometric, elongated, having smooth boundaries, and showing a weak preferential orientation. The deformation and recrystallization characteristics of quartz indicate high-temperature recrystallization (the grain boundary migration recrystallization mechanism). Schist and phyllite rock types are preferentially very-fine to fine-grained, showing a strong shape preferred orientation. Their sedimentary origin was indicated by the presence of graphite. The deformation and recrystallization characteristics of the quartz indicate low temperature conditions of their metamorphism., Šárka Šachlová, Vladimír Schenk and Zdeňka Schenková., and Obsahuje bibliografii
During the International expedition of the research vessel Dmitry Mendeleyev three sectors of the Western Pacific Ocean were studied: Philippine Sea, Solomon Sea and Coral Sea. From these areas also the samples for the orientation were taken in order to do the mineralogical examination with them. Above all, X-ray diffraction technique was used beside the chemical analysis performed by electron microprobe analyzer. Quantitative evaluation of min eral components was carried out applying X-ray diffraction. Standardless technique based on the adiabatic principle enabled th e quantitative determination directly from the X-ray diffraction diagram. Generally, sheet silicates - above all smectite, chlorite, mica (illite) - play the leading role in the mineral composition of collected samples of muds taken from the ocean floor. Besi des, also minerals of terrigenous origin are present: quartz prevailing mostly over feldspars (plagioclase > K-feldspar). Amphiboles and pyroxenes occured, but not everywhere. Carbonate minerals (calcite >> aragonite) were found only in samples from Coral Sea., Karel Melka, Ferry Fediuk and Anna Langrová., and Obsahuje bibliografické odkazy
The Dubair-Shang granitoids are the major intrusive bodies in Besham group and are exposed along the Karakoram Highway in Besham and lower Kohistan districts. A variety of these granitoid rocks have been investigated in terms of their petrographic features and physico-mechanical properties. The studied rocks are classified into four different textural varieties including Dubair mylonitized (DM), Dubair coarse grained (DCG), Shang coarse grained (SCG) and Shang foliated (SF) granitoids based on field observations and petrographic features. Petrographically quartz, potash feldspar, plagioclase and biotite are the essential minerals present in all varieties in varying amount. Beside these hornblende, chlorite, epidote, ore mineral(s) and sphene are also present in the accessory amount. As a part of the present investigation some of the mechanical and physical properties including uniaxial compressive strength (UCS), uniaxial tensile strength (UTS), specific gravity, water absorption, total porosity, and Los Angeles abrasion were also determined. The combined approach of petrographic features with the physico-mechanical investigation revealed that the textural characteristics and mineralogy have a significant influence on the physico-mechanical properties of the studied rocks. It is determined that modal percentage of minerals, degree of alteration, recrystallization, grain size and shape, types of grain boundary contacts have significant effect on characteristics of these granitoids. Based on strength tests studied rocks fall in category of moderately strong to strong. The values of specific gravity, porosity, water absorption and Los Angeles are within the range permissible for their use as constructional materials except SF. Based on physico-mechanical properties and petrographic examination Dubair-Shang granitoids could be used as aggregate for the construction of road, railway tracks, embankment, adn canals., Tanveer Ahmad, Muhammad Rizwan, Zeeshan Hussain, Subhan Ullah, Zulfiqar Ali, Adnan Khan, Abuzar Ghaffari, Jabir Nazir, Faisal Kaleem, Noor Rahman, Iftikhar Ali, Abdus Saboor Khan and Hamid A. Khan., and Obsahuje bibliografii
The research has dealt with mineral composition of the dislocation clays developed on the Prague fault. The Prague fault is a tectonic boundary between underlying clayey slates of Záhořany series and Skalka quartzite. The fault zone is filled with clay or sandy-silt to silty-sand matrix with scattered fragments of the surrounding rocks either slates or quart zite. Quartz, illite, kaolinite, chlorite, sporadic feldspar and gypsum were identified in powdered preparations by X-ray diffraction. The clay fraction of the taken samples is composed of illite, less kaolinite and sporadic chlorite and gypsum., Pavel Hájek and Martin Šťastný., and Obsahuje bibliografické odkazy
The growth in the field of construction of shallow underground structures has been associated with construction of new roads, collectors and other structures. This contribution deals with modeling of distribution pattern of the maximum velocity amplitude (blasting vibration field) on surface basement. This basement will be situated within small distance from source of technical seismicity that is used as a part of technological processes. The model represents seismic effect of blasting operati on in shallow tunnel. Plaxis 2D modeling system and its dynamic module based on finite element method are used for this presentation., Martin Stolárik., and Obsahuje bibliografické odkazy
The study presents a modification to conventional finite element method under plane strain conditions to address the problem of successive excavation of linear parts of tunnels. Although the successive excavation is a three-dimensional mechanical problem, the designers often prefer 2D analysis owing to considerably simple and transparent geometric model and fast computations when compared to a 3D solution. The main idea behind the suggested method referred to as, 2D3D model, is to express the influence of excavation of a single stroke of soil not only in the particular cross section but in the entire soil body in front of and behind the examined profile. This is achieved by introducing special finite elements which have common triangular cross-section but are of infinite length in the longitudinal direction. The longitudinal approximations of the displacement field adopt the evolution of convergence measurements, while standard linear shape functions are kept in the element triangular cross-section. A profile corresponding to the city road tunnel Blanka in Prague with available convergence measurements was examined to verify the method. The results show that the method provides reasonably accurate results when compared to the convergence confinement method without the need to subjectively determine the lambda parameter. It also significantly reduces the computational time of a more versatile but complex 3D analysis., Tomáš Janda, Michal Šejnoha and Jiří Šejnoha., and Obsahuje bibliografii
Numerical modelling has been widely used in the underground excavation design, where the in situ stress state plays a crucial role in the stability analysis. However, determination of an exact stress state for a specific geological region remains uncertain due to the complicated tectonic nature and measurement limitations. The stability is thus better analysed by considering the in situ stress as a finite spectrum and pinpointing the possible worst-case scenario. The most probable scenarios of in situ stress states in the Rožná mine area were analysed based on the varying trends in principal stress ratio and mean stress values obtained from four different measurement/analysis campaigns. The influence of different in situ stress judgement on the deformation and failure characteristics of the Bukov Underground Research Facility (URF) (Phase II, Czech) were investigated by the finite volume program FLAC3D. Results show that the increased horizontal stress anisotropy and the mean stress level jointly increase the overall deformation and lower the URF stability. Such influences on the roadway horizontal convergence are more considerable than the vertical ones. A mathematical model considering mean stress and horizontal stress ratio was proposed to quantitatively describe the overall stability, especially useful for excavations possessing complicated configuration., Libin Gong, Kamil Soucek, Petr Waclawik, Martin Vavro, Lubomir Stas, Jan Nemcik and Sahendra Ram., and Obsahuje bibliografii