To make sound decisions about the remaining life of a structure, the precise calculation of the prestress losses is very important. In post-tensioned structures, the prestress losses due to creep and shrinkage can cause serviceability issues and can reduce flexural capacity. The Varina-Enon Bridge is a cable-stayed, precast, segmental, post-tensioned box girder bridge located in Richmond, Virginia. Observation of flexural cracks in the bridge by inspectors promoted a study regarding long-term prestress losses in the structure. For understanding and sustaining the structure throughout its remaining service life, accurately quantifying prestress losses is important. Two approaches are used to predict long-term prestress losses on the Varina-Enon Bridge. The first approach involves a finite element computer model of the bridge which run a timedependent staged-construction analysis to obtain predicted prestress losses using the CEB-FIP '90 code expressions for creep and shrinkage. The second approach involves the compilation of data from instrumentation mounted in the bridge to back calculate the effective prestress force. The analysis using the computer model predicted the prestress losses as 44.6 ksi in Span 5, 47.9 ksi in Span 6, 45.3 ksi in Span 9, and 45.9 ksi in Span 11. The prestress losses estimated from field data were 50.0 ksi in Span 5, 48.0 ksi in Span 6, 46.7 ksi in Span 9, and 49.1 ksi in Span 11. It can be seen that relative to the results of field data estimations, the finite element analyses underestimated prestress loss, but given the degree of uncertainty in each form of estimation, the results are considered to fit well. / Master of Science / In order to apply a precompression force to concrete structures, post-tensioned concrete employs stressed steel strands. To construct lighter, stiffer structures, this popular building technology can be used. The steel strands undergo a reduction in force known as prestress losses over time. To make good decisions about the remaining life of a structure, the precise calculation of the prestress losses is very important. The Varina-Enon Bridge is a post-tensioned concrete box-girder bridge in Richmond Virginia. In July of 2012, observation of flexural cracks in the bridge by the inspectors promoted a study regarding long-term prestress losses in the structure. Two techniques are used to predict long-term prestress losses for this bridge. A computer model of the bridge is used in the first method to calculate losses using the design code. In order to measure prestress losses, the second technique used data from sensors mounted on the bridge. It was found that the estimation of losses closely matched those predicted at the time of the bridge construction and the computer model results. Based on this the final conclusion is made that the prestress loss in the Varina-Enon Bridge is not significantly more than expected.

This master thesis is focused for design, respectively for creating counterproposal of existing structure of Motorway Bridge located at D1 motorway between Jánovce and Jablonov in district Levoča in Slovakia. This bridge is over a local road. The main aim of this thesis is design, analysis and assessment of bearing elements of bridge deck. For purposes of this thesis was created three variants of bridge deck. Detailed analysis was performed on bearing construction from post-tensioned precast beam with monolithing concrete slab. Two mathematic models were used for analysis of chosen variant. First model was spatial 3D shell construction. The purpose of this model was determinate cross spreading line of other constant load and live load. Second, flat 2D model, was for determination creep and shrinkage appeared from long-term load. These effects were observed in at advanced defined time nodes. Outcomes from upper mentioned model were used from design and assessment of bearing elements of bridge deck, design prestressed reinforcement cables and concrete reinforcement rods.

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My thesis is focused on a design and comparism of the highway bridge across Dolansky creek. The bridge is built by balanced cantilever method. The common span length is 110metres. The bridge is post-tensioned concrete structure.The static model is made of beams.The static analysis during lifespan of bridge is made by Time discretization analysis . The design of reinforcement is made for longitudinal section and cross section.

The topic of the thesis is the design and assessment of roadway bridge structure, which is curved in the horizontal plan with a very small radius. Bridges is part of the flyover crossing in Brno. There are designed two variations of which are further developed the variant of the two-chamber cross-section. Calculations and assessments are conducted in according to the valid European standards (Eurocodes). The static calculation is supplemented with a clear technical drawings and visualizations.

The subject of Diploma’s thesis is the design of a road bridge on the R1 expressway, at km 1,293 above the road III/51311. The main content is static calculation of supporting structure consisting of four spans. Four studies were processed and the first variant of double-girder monolithic structure was chosen. The range of spans is ranging from 25 m - 30 m. Double-girder consists of two post-tensioned concrete beams and reinforced concrete slab. Static models and load effects are solved in Scia Engineer. Bridge is located in the horizontal curvature, however, compromise was elected (because of small curvature), assessing the upright design. Calculation is made without effects of temperature, wind loads and horizontal forces causing by traffic.

Diploma thesis deals with reconstruction of old beam bridge in town Ledeč nad Sázavou. Three variants of reconsttruction were done. Detailed structural design report was done to one of them, streithening with post-tensioning. Calculation of load effect was solved with finite elemet method via software on grillage model. Construction was checked on ultimate limit state and serviceability limit state. Necessary drawings were elaborated to chosen method.

The final thesis is focused on design of valley bridging on I/38 road at the Havlickuv Brod bypass. The thesis contains study of the bridging area. For detailed assessment was chosen, from three variants, a two-beam cross-section girder of 4 spans. Load-bearing structure is designed as cast-in-place, post-tensioned, concreted at fixed falsework without phased construction. The serviceability limit state and the ultimate limit state were assessed. The thesis contains, apart from structural design, drawings and visualizations of the bridge.

The diploma thesis is focused on solving road bridge situated between Roudno and Razová village over the water basin Slezská Harta. Before the design itself 3 studies were created and compared together. The selected variant is a continuous box girder with inclined walls, post-tensioned by bonded cables. The girder of a total lenght 148,0 m and width 13,6 m is divided into three spans. Height of the girder is 3,3 m. A detailed structural design, including construction limit state assessment, prestress design and time dependent analysis verification is processed. The design and the assessments of temporary and permanent situations are made according to valid standarts and regulations. Drawings and vizualizations are parts of the diploma thesis.

This diploma thesis is about designing the structure of roof of swimming stadium. Three solutions are created - concrete arc with tie, steel truss slab and concrete pretensioned membrane. One choosed solution - concrete pretensioned membrane - is afterwards developed. In the beginning there are several designs of geometry fulfilling the requirements for given type of structure being created. In part of static calculation, the parametrical mathematical model in form of macro in APDL language for Ansys software has been created. Afterwards all the parameters (initial state of cables, level of pretension, dimensions of membrane and peripheral frame, etc.) has been optimized in order to the membrane be fulfilling criterias for ultimate limit state and serviceability limit state. Afterwards other selected parts of structure has been checked. On basis of designed geometry and design checks in static calculation the drawings of conctruction and designed parts has been created. In the end, the 3D model of the structure has been created in graphical software Rhinoceros. Then visualizations of structure in concstruction stages and after completion has been rendered.