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Behavior analysis of a ground anchor fixed length in fine grained soils
Chalmovský, Juraj ; Turček,, Peter (referee) ; Hrubešová,, Eva (referee) ; Miča, Lumír (advisor)
Ground anchors represent an important structural element in the area of ground engineering. Despite an extensive usage of these elements, their design is usually performed using simple empirical and semi-empirical methods. An application of these procedures brings to the design a number of simplifying assumptions. The goal of the dissertation is to refine the computational design of ground anchors, analysis and quantification of selected factors significantly affecting their load displacement behavior. Firstly, the finite element method is applied. Two novel constitutive models are used: Multilaminate Constitutive Model for Stiff Soils (Schädlich, 2012) involving post peak shear softening of overconsolidated cohesive soils and Shotcrete Model (Schädlich, 2014) involving tension softening after tensile strength is reached. First constitutive model was used in order to simulate progressive decrease of skin friction along the anchor fixed length. Second constitutive model was applied for the grout material. In the next step, experimental program including several anchor load tests was carried out. The goal of the experimental program was to confirm conclusions from numerical studies and to obtain relevant data for further back – analysis. A newly developed application, in which all the findings from numerical computations and experimental measurements are incorporated, is described afterwards. The application is based on the use of so-called load-transfer functions. The program verification was conducted through series of back analysis of investigation anchor load tests realized on four different construction sites in two different types of fine-grained soils. The verification of the application is followed by series of parametric studies in which an influence of input parameters values is analyzed. Dissertation is concluded by the summarization of the most important findings.
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Footbridge across the Berounka
Zlatuška, Karel ; Romportl, Tomáš (referee) ; Stráský, Jiří (advisor)
The diploma thesis deals with design of plan – curved footbridge over Berounka river near the town of Čivice. Three different options were developed. First option includes a single – beam prestressed integral construction with haunches. The second option includes suspension footbridge construction, where the bridge deck is suspended at one side. In the third option the main span is built from concrete segments. Those are suspended on a pair of steel arches. The access ramps are cast – in – place, and they are supported by round steel piers. This variant was finally chosen as the best one and it was further processed. The construction was analyzed with Scia Engineer 2015 software, considering the construction process. The footbridge was loaded with dead loads and live loads including traffic and thermal actions. The internal forces were calculated and the construction was assess to the serviceability and ultimate limit states. In terms of serviceability, stress in concrete sections and deformations were checked. In terms of the ultimate limit state, the ultimate load capacities were calculated. The steel arches and piers were checked for possibility of loss of stability by buckling. The loss of stability was also checked by the software. Finally the dynamic behaviour of the construction was assessed, especially the harmonic excitation response. Then the construction plan and the drawings were made. The drawings include overview drawings and detailed drawings.
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Prestressed membranes above circular and elliptical plan
Juchelková, Pavlína ; Hájek,, Petr (referee) ; Bažant, Zdeněk (referee) ; Fillo,, L´udovít (referee) ; Stráský, Jiří (advisor)
This doctoral thesis deals with suspension cable roof structures above a circular and elliptical plan. The methodology of analysis is based on a basic annular cable roof structure of an external diameter of 70 m. The roof structure is designed as a prestressed membrane from the precast panels made from lightweight structural concrete which are supported with the bearing and prestressing tendons that are radially led between the two peripheral rings. The structural arrangement and the process of construction are described. The static system is specified and the terms like self-anchored system or equilibrium state are also defined. Finally, the results of static analysis are discussed in detail. The main aim of the doctoral thesis is to design a roofing of football stadium terraces using the structures of a basic annular cable roof; and present two alternatives – above circular and elliptical plan. The circular alternative comes directly from basic annulus, only the main dimensions of the new-designed structure are correspondingly extended. The elliptical alternative is an alteration of the circular design. As the radial tendons are anchored to the flexible peripheral curved girders, and the structures form the self-anchored system, the horizontal tendon forces load the peripheral girders radially. Because of that, it is essential to design a state of stress in tendon to prevent the undesirable global bending moments on the peripheral girders, and subsequently large non-uniform horizontal and vertical displacements of structure. Therefore, a study of the optimal load of ellipse is carried out. On the basis of the study, two basic requirements to structural arrangement of the elliptical roof are formulated. To illustrate the importance of a correct design, the optimal and unsuitable structural arrangements are compared. Finally, the results of static analysis of the circular and elliptical roof are again discussed in detail.
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Analysis of direction dispersion of collagen fibers in soft tissues
Sádovská, Terézia ; Lisický, Ondřej (referee) ; Turčanová, Michaela (advisor)
The bachelor thesis deals with the directional distribution of collagen fibres in soft tissues especially in arteries and tendons. The first part gives basic information about anatomy of human vascular system, particulary structure of the arteries. There are explained polarization microscopy principle of materials exhibiting birefringence. Further is described relation between direction of density and mechanical properties expresses as modulus in tensile. In the next section, we will be defined stress in arterial wall using linear stregth and stiffness. In the last part of thesis will be observed dispertion of collagen fibres in tendon. This dispertion is described by circular distribution Von Mises. At the end is evaluated how dispertion of collagen fibres effects mechanical properties of arteries.
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Effect of electrical stimulation on soft tissue healing
Fošumpaur, Karel ; Jeníček, Jakub (advisor) ; Angerová, Yvona (referee)
First and last name: Karel Fošumpaur Supervisor: Mgr. Jakub Jeníček, Ph.D. Opponent of the thesis: Name of the thesis: Effect of electrical stimulation on soft tissue healing Abstract of the thesis: This bachelor thesis summarizes the current state of knowledge regarding the effectiveness of electrical stimulation on soft tissue healing by providing an overview of the issue. The aim of the thesis is to describe the current level of research on the subject in terms of its completeness, current stage and limitations. Fifteen peer-reviewed, relevant articles were included and analyzed through a systematic search. Through analytical analysis and evaluation of the studies, it is determined whether and under what conditions electrical stimulation is effective for soft tissue healing. The articles presented include studies testing the effectiveness of electrical stimulation for healing structurally damaged muscle, tendon, skin and ligament. The work provides a largely positive conclusion regarding the healing effect of electrical stimulation. Key words: electrical stimulation, healing, soft tissue, muscle, tendon, skin, connective tissue, ligament, regeneration, reparation, electrotherapy
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Collagen structures from cell culture to intact tendon
Hadraba, Daniel ; Jelen, Karel (advisor) ; Amler, Evžen (referee) ; Plášek, Jaromír (referee)
CHARLES UNIVERSITY and HASSELT UNIVERSITY / tUL Doctoral dissertation Collagen structures from cell culture to intact tendon ABSTRACT Author: Daniel Hadraba Promoters: Assoc. Prof. Karel Jelen | Charles University Prof. Marcel Ameloot | Hasselt University Co-promoters: Dr. Frantisek Lopot | Charles University Prof. Virginie Bito | Hasselt University Annotation Author: Ing. Mgr. Daniel Hadraba Doctoral thesis title: Collagen structures from cell culture to intact tendon Year: 2010 - 2017 Doctoral program: Doctor of Biomechanics at Charles University Doctor of Biomedical Science at Hasselt University / transnational University Limburg Departments: Dept. Anatomy and Biomechanics | Faculty of Physical Education and Sport | Charles University Dept. Biophysics | Hasselt University Promoters: Assoc. Prof. Karel Jelen | Dept. Anatomy and Biomechanics | Faculty of Physical Education and Sport | Charles University Prof. Marcel Ameloot | Hasselt University / transnational University Limburg Co-promoters: Dr. Frantisek Lopot | Dept. Anatomy and Biomechanics | Faculty of Physical Education and Sport | Charles University Prof. Virginie Bito | Hasselt University / transnational University Limburg Bibliography details: Pages 102 Figures 30 Tables 2 Equations 17 Keywords: tendon, collagen, crimps, orientation, aging,...
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Analysis of direction dispersion of collagen fibers in soft tissues
Sádovská, Terézia ; Lisický, Ondřej (referee) ; Turčanová, Michaela (advisor)
The bachelor thesis deals with the directional distribution of collagen fibres in soft tissues especially in arteries and tendons. The first part gives basic information about anatomy of human vascular system, particulary structure of the arteries. There are explained polarization microscopy principle of materials exhibiting birefringence. Further is described relation between direction of density and mechanical properties expresses as modulus in tensile. In the next section, we will be defined stress in arterial wall using linear stregth and stiffness. In the last part of thesis will be observed dispertion of collagen fibres in tendon. This dispertion is described by circular distribution Von Mises. At the end is evaluated how dispertion of collagen fibres effects mechanical properties of arteries.
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Behavior analysis of a ground anchor fixed length in fine grained soils
Chalmovský, Juraj ; Turček,, Peter (referee) ; Hrubešová,, Eva (referee) ; Miča, Lumír (advisor)
Ground anchors represent an important structural element in the area of ground engineering. Despite an extensive usage of these elements, their design is usually performed using simple empirical and semi-empirical methods. An application of these procedures brings to the design a number of simplifying assumptions. The goal of the dissertation is to refine the computational design of ground anchors, analysis and quantification of selected factors significantly affecting their load displacement behavior. Firstly, the finite element method is applied. Two novel constitutive models are used: Multilaminate Constitutive Model for Stiff Soils (Schädlich, 2012) involving post peak shear softening of overconsolidated cohesive soils and Shotcrete Model (Schädlich, 2014) involving tension softening after tensile strength is reached. First constitutive model was used in order to simulate progressive decrease of skin friction along the anchor fixed length. Second constitutive model was applied for the grout material. In the next step, experimental program including several anchor load tests was carried out. The goal of the experimental program was to confirm conclusions from numerical studies and to obtain relevant data for further back – analysis. A newly developed application, in which all the findings from numerical computations and experimental measurements are incorporated, is described afterwards. The application is based on the use of so-called load-transfer functions. The program verification was conducted through series of back analysis of investigation anchor load tests realized on four different construction sites in two different types of fine-grained soils. The verification of the application is followed by series of parametric studies in which an influence of input parameters values is analyzed. Dissertation is concluded by the summarization of the most important findings.
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