|
| |
|
|
Properties of alluvial sediments at Albertov, Prague
Chvílová, Martina ; Boháč, Jan (advisor) ; Lešner, Jeroným (referee)
Bachelor thesis deals with the sediments of river terraces in Prague, Albertov. On these sediments from the deep drill hole J6 in campus Albertov area I made eight grain measurements, processed grain curves and normatively classified terrace soils with classes S1, S2, S3 and F3, F4. They are sandy soils partly containing fine gravel or fine fraction admixture. I also performed the grain analysis on soils 1,5m deep in near morphological distance from the drill hole on which bases I searched for analogy between sediments on campus Albertov building site. They are recent soils of local and foreign digged material. In documented terrace material with S2 character was observed that with content of fine- grained fraction under ca. 5% the increase of the proportion of fine-grained admixture elevates the angle of sands natural slope.
|
|
|
Determination of erosion thickness of Brno Tegl
Malát, Richard ; Boháč, Jan (advisor) ; Hrubešová, Eva (referee) ; Miča, Lumír (referee)
The thesis deals with an application of the geotechnical numerical back analysis and several other geotechnical conventional techniques in estimating the thickness of eroded sediments. Investigated strata is the Lower Miocene marine clay, often called "Tegl" which was deposited in the Carpathian Foredeep in the eastern part of the Czech rep. Numerical back analysis is based on an assumption that erosion thickness of a soil can be derived from its stress sate represented by K0 coefficient (coefficient of earth pressure at rest). The erosion thickness given by the numerical back analysis is compared with two estimations using Baldwin-Butler's equation and Casagrande's concept of preconsolidation stress. The erosion thickness is also derived from K0 values given by two field probes: Flat dilatometer (DMT) and Push-in spade shaped pressure cell (PSPC). The numerical back analysis was applied to galleries and adits opened during site investigation of the Královo Pole Tunnels in Brno. Both the samples for laboratory analyses were taken and the field tests were carried out in area of Brno city. Discrepancy of the results is analyzed and the conclusion is that the results given by the four conventional mentioned techniques (Baldwin-Butler, Casagrande, DMT, PSPC) are strongly distorted if the investigated...
|
|
| |
|
|
Effect of added lime on consistency limits of silty clay
Sotorník, Viktor ; Boháč, Jan (advisor) ; Kudrna, Zdeněk (referee)
This work looks into the effect of added lime on consistency limits of silty clay. It was carried out under the support of GAUK 62008 grant. In this work changes of consistency limits of a loessy soil from the borrow pit Horky nad Jizerou with amount of added quicklime (CaO) and curing time were observed. From the development of consistency limits the lowest amount of quicklime needed for the establishment of long - term (pozzolanic) reactions in the soil was determined. Consistency limits were determined following standardized procedures in an accredited laboratory. Determination of the liquid limit was conducted using the 80 g/30ř fall cone. Firstly sample heating caused by the exothermic nature of the slaking reaction CaO + H2O → Ca(OH)2 + heat and rapid soil flocculation after the lime addition were observed. Furthermore increase of the plastic limit, unpredictable behavior of the liquid limit and therefore influenced behavior of the plasticity index in agreement with findings stated in the research part were observed. The results showed finishing of the modification reactions within 48 hours after the lime addition too. Findings stated by Rogers et al. (1997) about the value of the lowest amount of quicklime determined by the consistency limits method being lower than the value determined by...
|
|
|
Secondary compression of Brno Tegel
Pavlová, Martina ; Boháč, Jan (advisor) ; Král, Jan (referee) ; Rozsypal, Alexandr (referee)
Observation and measurement of long-term volumetric deformation of clay are important in tackling different geotechnical and geological issues. The area of interest is the northern part of Vienna Basin, where Miocene clays sedimented. It is locally known as Brno Tegel. The Thesis deals with the secondary compression of clays, which can be defined by the Cα/Cc concept. The one-dimensional creep can be determined using the numerical values of the coefficient of secondary compression Cα and subsequently the thickness of overburden of sediments can be estimated. The two different theories, known as Hypothesis A and B are also discussed, which have been used to interpret the effect of creep during the primary consolidation phase. The laboratory measurements of long-term oedometric tests are presented for two undisturbed samples and one reconstituted sample of Brno clay. A nonstandard behaviour in uniaxial creep is also discussed, namely the observed diffusion collapse. Powered by TCPDF (www.tcpdf.org)
|
|
|
Modelling of soil asymptotic behaviour using discrete element method
Jerman, Jan ; Mašín, David (advisor) ; Boháč, Jan (referee)
Aim of this study is to characterize asymptotic states of particulate materials, including states in extension. Asymptotic states are defined as states reached after a sufficiently long stretching with a constant direction of the strain rate. They are attractors in the behaviour of granular material and they are reached independetly of the initial state. Discerete element method is used in the simulations, where the influence of strain rate direction on the final state is studied. Results for strain rate direction higher than 0 obtained by Mašín (2012a) are then compared with results for strain rate direction lower than 0. These sets of results coincide qualitatevely.
|
|
| |
|
| |
|
|
Comparison of a succes rate of sprint canoeists in junior and senior categories based on their international results.
Krpatová, Lucie ; Bílý, Milan (advisor) ; Boháč, Jan (referee)
Title: Comparison of a succes rate of sprint canoeists in junior and senior categories based on their international results. Aims: The aim of this work is to find out the potential future success of Czech junior medal winners in the adult category. Methods: We have chosen the method of data analysis to describe the course of a given sport career. The data was obtained by processing the results of the European Junior and Under 23 Championships from the period between 1996 and 2019, the World Junior and Under 23 Championships from the period between 1996 and 2019, the European Championship from the period between 1999 and 2019, the World Championship 1999 - 2019 and the Olympic Games 2000, 2004, 2008, 2012 and 2016. Results: The analysis of the results suggests that the training system and financial support dedicated to flatwater racing introduced in 2006 helped to significantly improve the success of Czech junior athletes at international events in all examined categories (men kayakers, canoeists, women kayakers). The analysis further showed that the success of the examined groups within senior categories has different tendencies. While the group of kayakers shows a small percentage of career termination under the age of 23 (23,5 %) and a relatively high success rate of winning medals in...
|
guest ::
RSS feed.