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Reliability Analysis of Steel Columns with Encased Web in High Strength Concrete under Compression
Puklický, Libor ; Krejsa,, Martin (referee) ; Melcher, Jindřich (referee) ; Kala, Zdeněk (advisor)
The presented paper deals with a theoretical analysis of the ultimate limit state. The results of experimental research carried out at the Institute of Metal and Timber Structures headed by Assoc. Prof. Karmazinová and Professor Melcher were applied. The geometrically and materially nonlinear solution based on the Timošenko’s solution is verified by the FEM model in the computer programme system ANSYS. The random influence of initial imperfections is taken into consideration. The FEM model also includes the influence of residual stress. In the parametric study, the influence of residual stress on the cross-section plastification is researched into, its influence on the load carrying capacity limit is, together with the influence of other imperfections, the subject of the stochastic analysis, applying the Latin Hypercube Sampling (LHS). Further on, the study proves a direct effect of the concrete part of the cross-section (combination of materials steel-concrete) on the decrease of load carrying capacity limit of the beam caused by influence of the residual stress of steel. With regard to the importance of time dependent phenomena of the concrete creep for the load carrying capacity, the studies given in the Ph.D. thesis are oriented in this respect. The parametric studies of the influence of the concrete creep having applied the Standard Eurocode 2 provide both a comparison of load carrying capacity limits when using common and high-strength concrete types, and also the variability of load carrying capacities. It follows from the comparison of the statistical analysis outputs according to the design reliability conditions of the Standard EN1990 and of the approach of Eurocode 4 that the Eurocode 4 can be recommended for dimensioning of this member type. According to the studies which we carried out, the design in compliance with Eurocode 4 can be evaluated as the reliable one. A larger set of experimental data is necessary to determine the economy.
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Removal of the masonry pillar in the front wall of the apartment house
Vítková, Barbora ; Bažant,, Zdeněk (referee) ; Strnad, Jiří (advisor)
This thesis focuses on the removal of the masonry pillar from the front wall of an apartment house. The masonry pillar should be replaced with two steel columns in a given axis distance. The parts of the thesis are a technical report, a static calculation and a graphic documentation. The description of the current object and the proposed solution is included within the technical report. The static calculation deals with a calculation of the strain and the enhancement of the current ferroconcrete lintel on the ground and first floor. A proposal of the solution, which is determined by the static calculation, is evident from the graphic documentary.
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Roofed Footbridge
Janírek, Karel ; Buchta, Stanislav (referee) ; Barnat, Jan (advisor)
The content of the master’s thesis is a design and evaluation of the timber construction of roofed footbridge for pedestrians and cyclists across the river Bělá in Jeseník in two different options of structure. The final version is solve in detail. It is a bridge with a span of 32 m and width of 4 m. The supporting structure is made of two two-hinged arch of glued laminated timber with lower deck and steel suspender. The bridge deck consists of two main girders, cross beams and stringers. Roof is from arches, roof beams, steel columns and cross beams. The stability of the whole construction is provided with horizontal longitudinal bracing in the plane of the deck and in the plane of the roof. The calculations are processed according to Czech technical norms ČSN EN.
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Multi-Storey Administrative Building
Tomeš, Martin ; Bajer, Miroslav (referee) ; Barnat, Jan (advisor)
The diploma thesis deals with the design of the administrative building from steel S420, S355 and concrete C25 / 30 with reinforcement made of steel B500B. The office building is a column-type with reinforced concrete ceiling. The building is equipped with a footbridge on the 10th floor. Two variants have been elaborated. Both of them were calculated in the program Scia Engineer. The winning variant is processed in detail.
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The superstructure of the apartment building
Kollárik, Adrián ; Bažant,, Zdeněk (referee) ; Strnad, Jiří (advisor)
The diploma thesis deals with superstructure of apartment building in brno, which is located in a row house construction. The goal of the diploma thesis is to design new supporting structures and minimize the load from these construction because of low reservs in the load capacity of the existing supporting walls. the thesis contains a technical report, analysis of statics, drawing documentation and visualization. The internal forces were executed by software scia engineer.
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The superstructure of the apartment building
Kollárik, Adrián ; Bažant,, Zdeněk (referee) ; Strnad, Jiří (advisor)
The diploma thesis deals with superstructure of apartment building in brno, which is located in a row house construction. The goal of the diploma thesis is to design new supporting structures and minimize the load from these construction because of low reservs in the load capacity of the existing supporting walls. the thesis contains a technical report, analysis of statics, drawing documentation and visualization. The internal forces were executed by software scia engineer.
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Multi-Storey Administrative Building
Tomeš, Martin ; Bajer, Miroslav (referee) ; Barnat, Jan (advisor)
The diploma thesis deals with the design of the administrative building from steel S420, S355 and concrete C25 / 30 with reinforcement made of steel B500B. The office building is a column-type with reinforced concrete ceiling. The building is equipped with a footbridge on the 10th floor. Two variants have been elaborated. Both of them were calculated in the program Scia Engineer. The winning variant is processed in detail.
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|
Removal of the masonry pillar in the front wall of the apartment house
Vítková, Barbora ; Bažant,, Zdeněk (referee) ; Strnad, Jiří (advisor)
This thesis focuses on the removal of the masonry pillar from the front wall of an apartment house. The masonry pillar should be replaced with two steel columns in a given axis distance. The parts of the thesis are a technical report, a static calculation and a graphic documentation. The description of the current object and the proposed solution is included within the technical report. The static calculation deals with a calculation of the strain and the enhancement of the current ferroconcrete lintel on the ground and first floor. A proposal of the solution, which is determined by the static calculation, is evident from the graphic documentary.
|
|
|
Reliability Analysis of Steel Columns with Encased Web in High Strength Concrete under Compression
Puklický, Libor ; Krejsa,, Martin (referee) ; Melcher, Jindřich (referee) ; Kala, Zdeněk (advisor)
The presented paper deals with a theoretical analysis of the ultimate limit state. The results of experimental research carried out at the Institute of Metal and Timber Structures headed by Assoc. Prof. Karmazinová and Professor Melcher were applied. The geometrically and materially nonlinear solution based on the Timošenko’s solution is verified by the FEM model in the computer programme system ANSYS. The random influence of initial imperfections is taken into consideration. The FEM model also includes the influence of residual stress. In the parametric study, the influence of residual stress on the cross-section plastification is researched into, its influence on the load carrying capacity limit is, together with the influence of other imperfections, the subject of the stochastic analysis, applying the Latin Hypercube Sampling (LHS). Further on, the study proves a direct effect of the concrete part of the cross-section (combination of materials steel-concrete) on the decrease of load carrying capacity limit of the beam caused by influence of the residual stress of steel. With regard to the importance of time dependent phenomena of the concrete creep for the load carrying capacity, the studies given in the Ph.D. thesis are oriented in this respect. The parametric studies of the influence of the concrete creep having applied the Standard Eurocode 2 provide both a comparison of load carrying capacity limits when using common and high-strength concrete types, and also the variability of load carrying capacities. It follows from the comparison of the statistical analysis outputs according to the design reliability conditions of the Standard EN1990 and of the approach of Eurocode 4 that the Eurocode 4 can be recommended for dimensioning of this member type. According to the studies which we carried out, the design in compliance with Eurocode 4 can be evaluated as the reliable one. A larger set of experimental data is necessary to determine the economy.
|
|
|
Roofed Footbridge
Janírek, Karel ; Buchta, Stanislav (referee) ; Barnat, Jan (advisor)
The content of the master’s thesis is a design and evaluation of the timber construction of roofed footbridge for pedestrians and cyclists across the river Bělá in Jeseník in two different options of structure. The final version is solve in detail. It is a bridge with a span of 32 m and width of 4 m. The supporting structure is made of two two-hinged arch of glued laminated timber with lower deck and steel suspender. The bridge deck consists of two main girders, cross beams and stringers. Roof is from arches, roof beams, steel columns and cross beams. The stability of the whole construction is provided with horizontal longitudinal bracing in the plane of the deck and in the plane of the roof. The calculations are processed according to Czech technical norms ČSN EN.
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