This paper pursues the effect of changes in distance and vibration frequency on the vibration velocity amplitude. As an example, we used the vibrating sheet piles at the cons truction of a new multi-functional FEI building on the premises of VŠB - TU Ostrava, at 17 listopadu street. The effect of these changes is monitored both in in-situ measurements and in a simulated real-life situation. The calculation software Plaxis 2D is used for creation of numer ical models. At the close, the results from in-situ measurements are confronted with those achieved from the models., Tomáš Petřík, Eva Hrubešová and Markéta Lednická., and Obsahuje bibliografické odkazy
Existence of piedmont zone in a river bed is a critical parameter from among numerous variations of topographical, geological and geographical conditions that can significantly influence the river flow scenario. Downstream flow situation assessed by routing of upstream hydrograph may yield higher flow depth if existence of such high infiltration zone is ignored and therefore it is a matter of concern for water resources planning and flood management. This work proposes a novel modified hydrodynamic model that has the potential to accurately determine the flow scenario in presence of piedmont zone. The model has been developed using unsteady free surface flow equations, coupled with Green-Ampt infiltration equation as governing equation. For solution of the governing equations Beam and Warming implicit finite difference scheme has been used. The proposed model was first validated from the field data of Trout Creek River showing excellent agreement. The validated model was then applied to a hypothetical river reach commensurate with the size of major tributaries of Brahmaputra Basin of India. Results indicated a 10% and 14% difference in the maximum value of discharge and depth hydrograph in presence and absence of piedmont zone respectively. Overall this model was successfully used to accurately predict the effect of piedmont zone on the unsteady flow in a river.
A large single-ring infiltrometer test was performed in order to characterize the saturated hydraulic conductivity
below an infiltration basin in the well field of Lyon (France). Two kinds of data are recorded during the experiment:
the volume of water infiltrated over time and the extension of the moisture stain around the ring. Then numerical
analysis was performed to determine the saturated hydraulic conductivity of the soil by calibration.
Considering an isotropic hydraulic conductivity, the saturated hydraulic conductivity of the alluvial deposits is estimated
at 3.8 10–6 m s–1. However, with this assumption, we are not able to represent accurately the extension of the moisture
stain around the ring. When anisotropy of hydraulic conductivity is introduced, experimental data and simulation results
are in good agreement, both for the volume of water infiltrated over time and the extension of the moisture stain.
The vertical saturated hydraulic conductivity in the anisotropic configuration is 4.75 times smaller than in the isotropic
configuration (8.0 10–7 m s–1), and the horizontal saturated hydraulic conductivity is 125 times higher than the vertical
saturated hydraulic conductivity (1.0 10–4 m s–1).
An identification of the responsible faults for the destructive earthquakes of 1894 in the Atalanti region was carried out by employing a novel application of 3D finite-difference wavefield modeling. Several faults proposed in the literature were tested in detailed 3D simulations, by also utilizing a detailed local 3D velocity model, as well as the local topography. The assessment of the most probable sources for these events was based on the correlation of reported damages with the distribution of the simulated peak ground acceleration. Furthermore, the distribution of the spectral amplitudes at higher frequencies that are related to the resonant frequencies of the local buildings on that time period was also used as an indicator. The general effect of the local 3D subsurface structure on the propagation of the wavefield and the spatial distribution of the ground motion was also investigated. The Malessina fault was identified as a probable source for the main event of 20/4/1894 based on the results of the 3D modeling, whereas the 3D effect was found to be a highly contributing factor to the distribution of the simulated ground motion., Mouzakiotis Evangelos, Karastathis Vassilios, Voulgaris Nikolaos,Papadimitriou Panagiotis, Sboras Sotirios and Gerolymatos Ilias., and Obsahuje bibliografii
The problem of bumps occurrence in deep mines during the long wall mining appears to be one of the most serious one in the design of engineering of mining. The bumps are caused for various reasons, but basically it is an aftermath of the accumulated energy, which is released under some unfavorable conditions. In this paper the influence of given dislocations and their slope in a coal seam are studied based. The numerical tool is the free hexagon method. This method belongs to a set of discrete element methods and enables us to define and calculate stresses in a natural way along the interfacial boundaries of adjacent particles (elements). Since the bumps are affected by a possible slip along the dislocations, dynamical response has to be taken into account. The velocity of excavation of the mine is considered by successive change of values of Eshelby’s forces on the face of the wall., Petr Pavel Procházka, Jiřina Trčková and Tat Seng Lok., 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
In accordance with the Directive 2008/105/EC Member States may designate regulatory mixing zones adjacent to points of discharge. Concentrations of one or more substances listed in Part A of Annex 1 of this Directive may exceed the relevant EQS within such mixing zones if they do not affect the compliance of the rest of the body of surface water with those standards. As a basis for designating regulatory mixing zone adjacent to an existing point source is the best knowing of the really hydrodynamic mixing zone very important. That’s the reason, why conductivity in the Elbe River dowstream waste water treatment plant (WWTP) Hradec Králové was measured. Numerical analysis of results is described in this paper. WWTP Hradec Králové is located on the left shore of the Elbe River and belong between one of the biggest Czech Republic´s WWTP of a size in excess of 100 000 PE. The region after complete vertical mixing is of interest in this study. Modeling of the two-dimenzional (2D) contaminant spreading of plume from point source in a river based on the method of Fisher et al. (1979) with correction for the effective origin of effluent is used. Comparison of the numerical results with field measurements shows that this method is useable for prediction of the hydrodynamic mixing zone adjacent to WWTP Hradec Králové in case when the effluent is positively buoyant. and Ve shodě se Směrnicí 2008/105/ES mohou členské státy vymezit regulační mísící zóny přilehlé k místu vypouštění. Koncentrace jedné nebo více látek uvedené v seznamu v části A přílohy 1 této směrnice smějí překračovat významné normy environmentální kvality uvnitř takových regulačních mísících zón, pokud nebudou mít vliv na dodržení těchto norem ve zbývající části vodního útvaru. Jako základ pro vymezení regulační mísící zóny přilehlé k existujícímu bodovému zdroji znečištění je velmi důležitá co nejlepší znalost skutečné hydrodynamické zóny. To je důvod, proč byla v Labi pod čistírnou odpadních vod (ČOV) Hradec Králové měřena konduktivita. V tomto článku je popsána modelová interpretace výsledků měření. ČOV Hradec Králové se nachází na levém břehu Labe a patří mezi jednu z největších ČOV v České republice s kapacitou přesahující 100 000 EO. Studie se zajímá o oblast po kompletním vertikálním promísení. Je použito modelování dvoudimenzionálního (2D) šíření vlečky znečištění z bodového zdroje v řece, založené na metodě, kterou uvádí Fischer et al. (1979) s korekcí pro účinný začátek vypouštění. Porovnání numerických výsledků s výsledky z terénního měření ukazují, že metoda je použitelná pro predikci hydrodynamické mísící zóny přilehlé k ČOV Hradec Králové v případě, že odpadní vody jsou v recipientu positivně nadlehčovány.
The reinforcement corrosion is the phenomenon that highly affects the reliability and durability of reinforced concrete structures. From that reason, a lot of researchers in Slovakia and in the world pay their attention to reinforcement corrosion. In the frame of the research work, the reinforced concrete girder bridges were diagnosed and observed. These bridges are influenced by reinforcement corrosion of main girders. The paper is concerned with detection and simulation of corrosion of steel reinforcement in the reinforced concrete. The cracking response of the reinforced concrete beams due to the corrosion effect of the steel reinforcement was analyzed. The effect of corrosion was simulated by the nonlinear numerical analysis using the program ATENA - 2D and 3D module. and Obsahuje seznam literatury
Combination of numerical models of deformations and repeated geodetic measurement results provide reliable information on the state of the rock mass in a mining area and support planning and control of the mining operation. The paper describes the concept of integrated monitoring and analysis of rock mass deformation in the Kvannevann iron ore mine (Norway) using sub-level caving (SLC) method. Geodetic control network developed for periodic measurements of surface subsidence and a source of geometrical data for numerical modelling of deformations using finite element method (FEM) has been characterised. Focus is given to the results of initial numeric al analyses with FEM of rock mass deformations due to SLC mining. The results of the modelling provided information on possible extent of deformation zones on the mining ground surface once mining with new method commences., Jan Blachowski and Steinar Ellefmo., and Obsahuje bibliografické odkazy
Numerické metódy majú v skúmaní seizmického pohybu nezastupiteľnú a stále dôležitejšiu úlohu. Metóda konečných diferencií je v súčasnosti dominantnou metódou. Pokrok v jej aplikácii na seizmologické problémy súvisí s úsilím o realistickejšie modely a výpočtovú efektívnosť., Peter Moczo, Jozef Kristek., and Obsahuje seznam literatury