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
The known models of recent vertical movements of the Earth crust surface in the area of Poland were processed in the form of contour line map on the basis of the data of the first and second class geometric state levelling network. Second map done by Wyrzykowski (1985) was based on the results of measurements made in 1871-1882, 1926-1937, 1952-1956 and 1975-1977. The newest results of assignment of recent vertical movements of the Earth surface in the territory of Poland were published by Kowalczyk in 2006. The map of the contemporary vertical movements velocities has been processed using the least squares collocation method on the basis of repeated measurements of state precise levelling, executed mainly in 1974-1982 and 1997-2003. Presently, after about 3 years of satellite observations at about one hundred of permanent GPS stations of the ASG-EUPOS network, a verification of the mentioned models is possible on the basis of independent (satellite) measurements. As the resolution of the stations in Poland is sufficient, the model processed using satellite data was determined for the whole area of Poland and it was confronted with earlier (levelling) models. There are some differences in the analyzed models. A comparison of levelling and satellite mode ls indicates defect of reference distinctly resulting from sea level variability., Bernard Kontny and Janusz Bogusz., and Obsahuje bibliografické odkazy
Arsenic, antimony and selenium belong to toxic contaminants with high environmental risk. In contrast to metal cationic contaminants (Be, Zn, Cd, Hg Pb, etc.) the metalloids and nonmetals of groups 5 and 6 of periodic system generally form the oxyanions in two oxidizing states (i.e. arsenates and arsenites, antimonates and antimonites, as well as selenates and selenites) in dependence on redox potential and pH value. It is well known that above mentioned oxyanions have a strong adsorption affinity to hydrated oxides and/or oxides hydroxides of Fe, Al and Mn, preferably Fe forming stable surface complexes. In fact, commercially produced Fe oxides-based sorbents are too expensive for strongly contaminated aqueous systems. Aluminosilicates have opened new possibilities in sorption technology due to favourable surface properties, availability, environmental and economical reasons, but they are not selective sorbents of anionic contaminants thanks to a low pHZPC. A simple Fe/Al/Mn pre-treatment of raw aluminosilicates can significantly improve their sorption affinity to oxyanionic contaminants, including arsenites and arsenates, selenites and selenates and antimonites and antimonates, respectively. Different types of natural and/or second-rate clays (metakaolines with the large content of Fe, raw bentonites and natural clinoptilolite-rich tuff, ) from Central European localities were used for FeII, FeIII, AlIII and MnII pre-treatment., Barbora Doušová, Lucie Fuitová, Lenka Herzogová, Tomáš Grygar, David Koloušek and Vladimír Machovič., and Obsahuje bibliografii
The present paper describes a method for identification of reflected waves on the seismogr ams from a cluster of quarry blasts. These reflections are used for determination of the Moho depth. Only one seismic station is sufficient, but a cluster of seismic sources is needed. To increase the signal-to-noise ratio of reflected waves, several techniques are applied, such as filtering, polarisation analysis and stacking of seismograms. Th e method was tested on seismic data from the central part of the Ore Mountains region, Czech Republic. Seismic waves were generated by strong quarry blasts at the Tušimice open-pit coal mine, and recorded at the Přísečnice (PRI) temporal seismic station at an epicentral distance of about 16 km. As the station was equipped with a three-component seismograph, also S-wave onsets could be determined. Although Pg, Sg and surface waves dominate the seismograms, weak Moho reflections of P and S waves could also be recognized at travel times of 9.7 s and 17.3 s, respectively. From these times we found the mean ratio of the P- to S-wave ve locities in the crust to be 1.78. Considering P-wave velocity model of Beránek (1971), the observed travel times of the reflections yield a crustal thickness of 29.5 -n31.5 km, which agrees with recent receiver function studies. These agreements indicate that the proposed method of reflected seismic waves, generated by quarry blasts, could represent a simple way for mapping the Moho discontinuity., Hana Kampfová, Jiří Málek and Oldřich Novotný., and Obsahuje bibliografické odkazy
A collaborative group between Greek, Polish, and Sl ovak colleagues installed a dense network of non-permanent GPS stations and extensometers to monitor active faults in the eastern part of the Gulf of Corinth, central Greece. The network includes eleven GPS stations across the Kaparelli fault and the Asopos rift valley to the east and two TM-71 extensometers that were installed on the Kaparelli fault plane. So far the G PS network has been measured in three campaigns within the last three years with very good accuracies (1-4 mm in the horizontal plane). Although it is early to draw conclusions on the velocity field and on strain patterns it can be noted that, the data from the extensometers demonstrate both fault-normal opening and shear motion. Given that the total offset on the Ka parelli fault is small, and the geological data suggesting a segmented character of this fault, we expect in the near fu ture to differentiate fault slip and strain accumulation among segments., Athanassios Ganas, Jaroslaw Bosy, Lubomir Petro, George Drakatos, Bernard Kontny, Marian Stercz, Nikolaos S. Melis, Stefan Cacon and Anastasia Kiratzi., and Obsahuje bibliografické odkazy
The medieval Jeroným Mine is a mine working in which places of various degrees of rock mass disintegration are there. Time-lapse recording, which has been performed in the Jeroným Mine since the year 2009, was induced by a necessity of documenting both areas of flaking-off and caved areas owing to an increased rate of occurrence of flaking-off phenomena in mine workings - rooms K3 and K4 of this mine. The methodology of recording, which uses as a basis repeated recording in time in the framework of geotechnical measurements carried out quarterly, is based on the principle of maintenance of not only parameters of images themselves, but also of location of a photo device used for documentation provision. This process is followed by the creation of information sheets of areas of flaking-off and caved areas and their classification. The method of recording was used owing to a high degree of disintegration of the rock mass in selected mine workings, a possibility of extension of caved areas and also the high rate of occurrence of subsidence phenomena occurring above those workings and even sporadically reaching the mine workings. Time-lapse recording is thus performed primarily in mine workings with reduced stability, situated very close to the surface. With regard to the principle of this method, results will be known only in further years., Radovan Kukutsch, Petr Žůrek and Martin Stolárik., and Obsahuje bibliografii
The Betic Cordillera, located at the westernmost end of the Mediterranean alpine belt, is deformed by overprinted folds and faults that produced the present-day relief since the Tortonian. In the frame of the COST 625 action, four sectors have been studied in the central part of the cordillera. In the Granad a Depression, the large NW-SE Padul normal fault deforms the SW periclinal end of the Sierra Nevada antiform. MT surveys in dicate the continuity in depth of high and low angle normal seismogenic faults and the presence of act ive detachment faults. In Tabernas regi on a good example of interaction between a N W-SE propagating normal fault, E-W strike-slip faults and the fold system is studied. In the Sierra Tejeda-Zafarraya and in the Balanegra-Sierra de Gádor areas, two new GPS networks ha ve been installed to determine the interaction and the development of large antiformal struct ures and normal faults with E-W and NW-SE orientations. However, taking into account the low tectonic activity of the studi ed region, a period of more than 5 year could be needed to determine with enough accuracy the development rate of the structures., Jesús Galindo-Zaldívar, Antonio Gil, Carlos Sanz de Galdeano, Stefan Shanov and Dumitru Stanica., and Obsahuje bibliografické odkazy
The knowledge of the curing process of polysiloxane resin is an important factor for the optimal preparation of the precursor of ceramic materials/composites/. It was observed that different physical method explaining the cure process e.g. /IR, NMR/ and examined experimentally the method of dielectric analyses/DA/. It was found that the method DA with the addition of the dopant makes the monitored system to increase its conductivity for the certain type of polymer. This enables to influence the properties of the final composite during its curing with the help of the approprietly selected temperature and pressure depending on time., Petr Hron, Miloslav Burian, Šárka Hytychová, Adolf Inneman and Zbyněk Sucharda., and Obsahuje bibliografii