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Measurement of stiffness at small strains during oedometer test and detailed interpretation of output waves
Havlíček, Jaroslav ; Koudela, Pavel (referee) ; Chalmovský, Juraj (advisor)
This thesis has a theoretical and a practical part. The first part contains theoretical introduction to the phenomenon of increased stiffness at very small strains and possibilities of its practical applications. The available methods for evaluating initial shear modulus tests are described below. Increased attention is paid to the method of evaluation of test data in the frequency domain using the Fourier transform. The last chapter in this part describes an algorithm designed for automatic evaluation of measurements in the frequency domain. The practical part deals with measurement and evaluation of initial shear modulus for Brno clay as a function of vertical stress in oedometric test. Firstly, a device is presented that allows the extension of the oedometric test with sensors for measuring initial shear modulus of soil. This device was designed for the test in this thesis. Subsequently, the test plan is described including description of all soil samples. In this thesis, several types of soil samples from a single site were tested. Next, the results of the individual tests are evaluated by the selected methods. Examples are used for showing the differences in evaluation of the same data by other methods. At the end, the results of the individual tests for all sample types are compared with each other and with data from literature.
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Optimization of the Material Parameters Based on Retaining Wall Monitoring
Koudela, Pavel ; Chalmovský, Juraj ; Miča, Lumír
Geotechnical monitoring is usually used for the verification of designed constructions. A result of the monitoring could be used as an alternative for the determination of material parameters involving optimization procedures. The optimization procedure will be used as a tool for determining material parameters using the inclinometer measurement of a retaining wall. The simple script involving data processing between Plaxis and optimization procedure Particle swarm optimization (PSO) was written. In this way, the input parameters of Brno Miocene clay for the Hardening Soil model were optimized. The results of the optimization procedures confirm the hypothesis, the optimization could be used as a useful tool for determining the material parameters of soils.
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Design of retaning structure in the Brno- sever district
Koporec, Vladimír ; Koudela, Pavel (referee) ; Miča, Lumír (advisor)
The bachelor's thesis deals with the design of the sheet pile construction of the construction pit of the underground car park of a multifunctional house in Brno and its impact on the adjacent tunnel. The design and assessment of the sheet pile structure is developed on the basis of the results obtained in the GEO5 program. For a more detailed analysis of the impact of the proposed sheet pile structure on the adjacent tunnel, a numerical analysis is performed in the PLAXIS 2D program. As part of this analysis, a study of the influence of the material model (Mohr-Columb, Hardening soil and Hardening soil small) on the change of deformations and internal forces in the tunnel is made. The results of the work show the interaction between the proposed structure and the tunnel.
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Dilatancy of soils as a factor influencing the bearing capacity and load - displacement response of deep foundations
Dvořák, Tomáš ; Koudela, Pavel (referee) ; Chalmovský, Juraj (advisor)
In theory of soil mechanic the dilatancy has a significant influence, which may fundamentally affect bearing capacity and behavior of geotechnical constructions. In the past it was difficult to include influence of dilatancy directly in to calculation, but now with development of numerical analysis and growth of computer performance it is much easier. In this work there are introduced fundamental dilatancy models and phenomen called constraint dilatancy, which causes stress changes in soil or at soil – construction interface. This stress changes may lead to higher bearing capacity. In this work, the effect of constraint dilatancy is focused on bored pile’s shaft. Next target of this work is including dilatancy to calculation. By empirical methods, by direct application with theory of cylindrical cavity expansion and last by numerical calculation with finite element method in software Plaxis with using the Hardening Soil model.
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Laboratory tests of geomechanical properties of Brno clay on reconstituted samples
Rozmánek, Filip ; Koudela, Pavel (referee) ; Chalmovský, Juraj (advisor)
This theses is focused on geomechanical properties of reconstituted Brno clay. The properties of reconstituted soils are different from properties of natural soils because of the ifluence of structure. The properties of reconstituted soils are termed „intrinsic properties“. Object of this theses is to describe these properties and to determine compressibility and strenght charakteristics of Brno clay using reconstituted samples. These charakteristics are obtained using the edometer machine, the triaxial machine and the ring shear apparatus. Calculated data are then compared with known data from literature.
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Back-analysis of instrumented load test of large-diameter bored pile using load-transfer method
Bírošík, Matej ; Koudela, Pavel (referee) ; Chalmovský, Juraj (advisor)
The thesis is divided into four parts. The first part is theoretical and consists of description of load-transfer method and its principal defined by (Reddy a ďaľší, 1998), where is explained calculating algorithm for predicting behaviour of loaded large-diameter bored piles. In the second part are all information about analysed instrumented load tests including measured values, which are interpreted by tables and graphs of load-transfer curves, load transfers in individual sections and shear friction values along the pile. This part also includes analyses of the influence of the pile axial stiffness uncertainty. The third part consists of parametric study. This study displays effects of different parameters on pile behaviour prediction during loading through load-transfer curves and load transfers in individual sections along the pile obtained from the programme developing at the Institute of Geotechnics, Faculty of Civil Engineering BUT in Brno, for large-diameter bored piles behaviour prediction. In the fourth part is evaluation and description of back-analysis of two instrumented load tests by already mentioned programme. The goal in the back-analysis was to reach the same parameters of load-transfer curves and load transfers in individual sections along the pile by surrounding soil parameters adjusting.
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Determination of input parameters of advanced soil constitutive models using optimization methods
Koudela, Pavel ; Miča, Lumír (referee) ; Chalmovský, Juraj (advisor)
Choice of the constitutive model and determination of input parameters are necessary for a successful application of numerical methods in geotechnical engineering. Higher complexity of modern constitutive models results in an increase of the number of input parameters and time requirements for their calibration. Optimization methods are a possible solution for this problem. An application in which metaheuristic optimization method Particle swarm optimization (PSO) is involved is presented in this thesis. Critical review and testing of various PSO alternatives was performed in the first part of this thesis. The most efective PSO alternatives were chosen. In the second part connection between PSO algorithm and finite element solver was prepared. Automatization of determination of constitutive models input parameters was performed on three boundary value problems: laboratory test (oedometer), in-situ test (pressuremeter) and geotechical construction (retaining wall). Three types of constitutive models are used. Linear elastic-perfectly plastic Mohr-Coulomb model, elastoplastic non-linear Hardening soil model and Hardening soil - small strain model.
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Pile design based on Penetration tests
Koudela, Pavel ; Leiter, Augustin (referee) ; Štefaňák, Jan (advisor)
Application of penetration tests at the design of piles foundation is the main subject of this thesis. The main target of this work is calculation of bearing capacity and settlement of single piles. In the thesis are use a new computational relations based on corelation which used relation between penetration values and parameters from laboratory tests. The bearing capacity of the pile is calculation from the derived relations, by the software and laboratory test, too. This types of calculations are executed for comparasion with new computational relations.
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Application for Production Evidence and Management
Koudela, Pavel ; Šeda, Miloš (referee) ; Poliščuk, Radek (advisor)
The aim of this thesis is a production management analysis in company SLB and creating design for supportive application implementation. Used technologies include structured analysis, object oriented programming, web technologies and a relational database. Server as well as client applications are platform independent and use modern programming techniques.
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