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Reliability analysis of embankment dams endangered by filtration deformations
Čejda, Marek ; Baroková,, Dana (referee) ; Fošumpaur, Pavel (referee) ; Říha, Jaromír (advisor)
Subject of the dissertation is a probability analysis on creation of embankment subsoil filtration deformations. Out of the broad topic of filtration deformations, the dissertation is focused at initiation of the process. At this phase, the overlying layers downstream of levee get uplifted, and eventually get breached. The process of downstream subsoil failure probability estimation is formulated using mathematical and statistical modelling. Within the scope of parametrical study the suggested method is applied onto a test environment. Results of the probability estimation are compared with results obtained using Limit state design method. The results of stochastic modelling can be used for improvement of Limit state design method precision.
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Analysis of boundary conditions of ground heat exchangers
Floreková, Skarleta ; Horák, Petr (referee) ; Hirš, Jiří (advisor)
Diplomová práca,, ,,Analysis of boundary conditions of ground heat exchangers,, je primárne zameraná na analýzu okrajových podmienok a hlavných faktorov vplývajúcich na spoľahlivý návrh a prestup tepla plošného zemného výmenníka v oblasti geotermálnych aktivít na kúpeľnom ostrove v Piešťanoch. Posúdenie možných vplyvov na životné prostredie, ako je napríklad vznik tepelných zmien v dôsledku extrakcie tepla vrátane zamŕzania pôdy v okolí potrubia a potenciálneho znečistenia podzemných vôd je taktiež rozoberané. Súčasťou tejto záverečnej práce boli spracované tri numerické analýzy metódou konečných prvkov pomocou softvéru COMSOL Multiphysics 5.6., ktoré sa môžu vyskytnúť v tejto konkrétnej oblasti. Prvá numerická analýza je podrobená štúdii dynamických procesov plošného zemného výmenníka tepla a zeminy nasýtenou vodou pri konštantnej teplotnej okrajovej podmienke pôdy. Dynamický proces zemného výmenníka tepla a nasýteného podložia pri nestálej teplotnej okrajovej podmienke je skúmaný v druhej numerickej analýze. Posledná analýza je vyhotovená na posúdenie prevádzky plošného zemného výmenníka tepla s možnosťou prúdenia podzemnej vody v rovnakej vrstve. Vďaka týmto numerickým štúdiám a výsledkom dynamických tepelných modelov, každá prípadová štúdia obsahuje rozloženie teplôt v zemine, výstupné teploty z výmenníka a vlastný čiastočný záver.
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Dewatering of foundation pit - numerical analysis
Krejzar, Vojtěch ; Boštík, Jiří (referee) ; Miča, Lumír (advisor)
The subject of the presented thesis is a foundation pit dewatering numerical analysis. The study is introduced with practical examples and the summary of the necessary theory. Individual subtasks are modeled as two or three-dimensional problem on a chosen foundation pit example. A comparison with analytical methods and theoretical knowledge about the problem is made. The studies focus on specifying the pumped water quantity, the shape of the depression curve, determining the size of the numerical model and the influence of the finite element network density. The steady-state flow cases, water table aquifer, a well system, sheet pile wall cutoff effect, surface drained pit and partial penetration cases are analyzed. The work proposes a method of modeling a well by FEM. The main output is a 3D analysis of a submerged excavation dewatered with a partially penetrated well system.
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Data processing of well log complex
Hanák, David ; Procházka, Martin (advisor) ; Kobr, Miroslav (referee)
This thesis is focused on the problem of the determination of shear surfaces of slope instabilities (including fossil ones) from the results of the complex of logging methods. It describes the steps taken during data measurement, processing, and interpretation. All the data comes from the measurements conducted in the boreholes carried out for the geotechnical survey of the sliding area in the immediate proximity of the D8 highway or measurements in a well from the Děčín-Loubí locality. On the second mentioned locality, due to a different well construction, a more extensive logging complex could be carried out. After locating shear surfaces in a slope instability, a comparsion was made to determine whether the results in neighboring boreholes corresponded to each other, and to evaluate which methods (or combination of methods) suits best for the task.
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Mathematical model of groundwater flow during operation of a circulation well
Žáková, Tereza ; Mls, Jiří (advisor) ; Šindelář, Jakub (referee)
In this master's thesis, a numerical model of groundwater flow in a contaminated area of Hradec Králové was created. After that, a circulation well was introduced. Two circulation well variants, which differ in the amount of pumped water, were examined. All simulations were performed with the aid of a finite element solver Feflow 5.2. The values of hydraulic head resulting from the mathematical model are in a good agreement with those obtained from the field measurement. The groundwater flow present in the area of interest exhibits south to southwest direction. After introducing the circulation well, I focused on the influence of the amount of pumped water on the groundwater flow. The outcome of this observation was that during the higher volume pumping, the circulation cell is larger and therefore has a higher influence on the groundwater flow. I evaluated that it is more efficient to pump a higher amount of water in the investigated area.
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Isotope hydrogeology and geothermal applications to clarify the origin, the sustainability and the character of groundwater flow: Bohemian and Aquitaine sedimentary basins
Jiráková, Hana ; Hrkal, Zbyněk (advisor) ; Rapantová, Naďa (referee) ; Michelot, Jean-Luc (referee)
Isotopic investigations combined with geothermal applications represent powerful tools for the exploration of groundwater potential as a drinking or geothermal resource. This Ph.D. Thesis combines both approaches, environmental and radioactive isotopes together with temperature data in deep aquifers, in order to enrich and update the knowledge concerning the aquifer recharge processes in the Aquitaine Basin (France) and the aquifer recharge processes and geothermal potential in the Bohemian Cretaceous Basin (Czech Republic). Stable isotopes (18 O, 2 H, 13 C) combined with radioisotope data (14 C, 3 H) are used to estimate the recharge timing and climatic conditions prevailing during the infiltration from the Late Pleistocene up to modern time. The character of groundwater recharge and regime are necessary to generate relevant source data for the accurate modelling of complex groundwater systems. Three groups of groundwater recharge types can be distinguished throughout Europe - (i) continuous recharge and (ii) interrupted recharge during Last Glacial Maximum and (iii) a group corresponding to particular recharge conditions. The contrasted geographic and climate conditions at both study sites in France and the Czech Republic have entailed a great heterogeneity of the recharge conditions and...
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Dewatering of foundation pit - numerical analysis
Krejzar, Vojtěch ; Boštík, Jiří (referee) ; Miča, Lumír (advisor)
The subject of the presented thesis is a foundation pit dewatering numerical analysis. The study is introduced with practical examples and the summary of the necessary theory. Individual subtasks are modeled as two or three-dimensional problem on a chosen foundation pit example. A comparison with analytical methods and theoretical knowledge about the problem is made. The studies focus on specifying the pumped water quantity, the shape of the depression curve, determining the size of the numerical model and the influence of the finite element network density. The steady-state flow cases, water table aquifer, a well system, sheet pile wall cutoff effect, surface drained pit and partial penetration cases are analyzed. The work proposes a method of modeling a well by FEM. The main output is a 3D analysis of a submerged excavation dewatered with a partially penetrated well system.
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Analysis of boundary conditions of ground heat exchangers
Floreková, Skarleta ; Horák, Petr (referee) ; Hirš, Jiří (advisor)
Diplomová práca,, ,,Analysis of boundary conditions of ground heat exchangers,, je primárne zameraná na analýzu okrajových podmienok a hlavných faktorov vplývajúcich na spoľahlivý návrh a prestup tepla plošného zemného výmenníka v oblasti geotermálnych aktivít na kúpeľnom ostrove v Piešťanoch. Posúdenie možných vplyvov na životné prostredie, ako je napríklad vznik tepelných zmien v dôsledku extrakcie tepla vrátane zamŕzania pôdy v okolí potrubia a potenciálneho znečistenia podzemných vôd je taktiež rozoberané. Súčasťou tejto záverečnej práce boli spracované tri numerické analýzy metódou konečných prvkov pomocou softvéru COMSOL Multiphysics 5.6., ktoré sa môžu vyskytnúť v tejto konkrétnej oblasti. Prvá numerická analýza je podrobená štúdii dynamických procesov plošného zemného výmenníka tepla a zeminy nasýtenou vodou pri konštantnej teplotnej okrajovej podmienke pôdy. Dynamický proces zemného výmenníka tepla a nasýteného podložia pri nestálej teplotnej okrajovej podmienke je skúmaný v druhej numerickej analýze. Posledná analýza je vyhotovená na posúdenie prevádzky plošného zemného výmenníka tepla s možnosťou prúdenia podzemnej vody v rovnakej vrstve. Vďaka týmto numerickým štúdiám a výsledkom dynamických tepelných modelov, každá prípadová štúdia obsahuje rozloženie teplôt v zemine, výstupné teploty z výmenníka a vlastný čiastočný záver.
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Data processing of well log complex
Hanák, David ; Procházka, Martin (advisor) ; Kobr, Miroslav (referee)
This thesis is focused on the problem of the determination of shear surfaces of slope instabilities (including fossil ones) from the results of the complex of logging methods. It describes the steps taken during data measurement, processing, and interpretation. All the data comes from the measurements conducted in the boreholes carried out for the geotechnical survey of the sliding area in the immediate proximity of the D8 highway or measurements in a well from the Děčín-Loubí locality. On the second mentioned locality, due to a different well construction, a more extensive logging complex could be carried out. After locating shear surfaces in a slope instability, a comparsion was made to determine whether the results in neighboring boreholes corresponded to each other, and to evaluate which methods (or combination of methods) suits best for the task.
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