Esta pesquisa propôs uma contribuição aos procedimentos de inspeção de pontes por meio de um plano de monitoramento de curta duração do comportamento dinâmico do tabuleiro de pontes rodoviárias de concreto com a utilização de receptores GPS de 100 Hz associado à diversas técnicas de filtragem de sinais. O estudo foi conduzido em uma ponte em serviço localizada na rodovia Fernão Dias (BR-381). O procedimento de inspeção proposto baseou-se no uso de dois sinais de satélites GPS, por meio da aplicação do Método Residual de Fase (MRF), e da análise temporal dos resíduos da dupla diferença de fase a partir da Fast Fourier Transform (FFT), Continuous Wavelet Transform (CWT), Passa-Faixa Chebyshev do Tipo I. A descrição do comportamento dinâmico do tabuleiro do vão central da ponte se deu por meio da extração dos valores de frequência e amplitude das deflexões verticais a partir dos dados GPS filtrados (resíduos), em três períodos de amostragem de 1 minuto. Os valores de frequência variaram de 0,5 Hz a 8 Hz nos três períodos de amostragens e também nos filtros FFT, CWT e Passa-Faixa Chebyshev do Tipo I. Os valores de amplitude de deslocamento vertical máximo ficaram em torno de 6 mm. Estes valores coincidiram com os valores de frequência e amplitude de deslocamento vertical registrados pela instrumentação clássica com acelerômetros, transdutores de deslocamento vertical, modelagem por elementos finitos e prova de carga estática e dinâmica realizadas sobre tabuleiro do vão central da ponte instrumentado. Por fim, pode-se afirmar que os procedimentos propostos, além de poderem ser utilizados como uma etapa preliminar de inspeção de tabuleiro de pontes rígidas possibilitaram a detecção de deslocamentos dinâmicos verticais milimétricos e suas frequências de vibração. / This research proposed a contribution for bridge inspection procedures at of a short-term monitoring plan of the dynamic behavior of the concrete road bridge with the use of 100 Hz GPS receivers associated with various signal filtering techniques. The study was conducted in the service bridge located on the highway Fernão Dias (BR-381). The procedure inspection proposed was based on the use of two satellite GPS signals, by applying the Phase Residual Method (PRM), and the temporal analysis of the residuals of the double difference phase from the Fast Fourier Transform (FFT), Continuous Wavelet Transform (CWT), Type I Chebyshev Band-Pass. The dynamic behavior of the central span of the bridge was described by extracting the frequency and amplitude values of the vertical deflections from the filtered GPS data (residues), in three sampling periods of 1 minute. The frequency values found ranged from 0.5 Hz to 8 Hz in the three sampling periods as well as in the FFT, CWT and Chebyshev Type I Band-Pass filters. The maximum vertical displacement peak values were around 6 mm. These values coincided with the vertical displacement and amplitude values recorded by the classical instrumentation with accelerometers, vertical displacement transducers, finite element modeling and static and dynamic load test performed on the central span deck of the instrumented bridge. Finally, it could affirm that the procedures proposed, besides being able to be used as a preliminary step of inspection of the rigid bridge\'s deck enabled the detection of millimetric vertical dynamic displacements and their frequencies of vibration.

In this thesis, several aspects of GPR data processing for RC bridge decks are studied. First, autofocusing techniques are proposed to replace the previous expensive and unreliable human visual inspections during the iterative migration process for the estimation of the velocity/dielectric permittivity distribution from GPR data. Second, F-K filtering with dip relaxation is proposed for interference removal that is important for both imaging and the performance of post-processing techniques including autofocusing techniques and CS-based migration studied in this thesis. The targeted interferes here are direct waves and cross rebar reflections. The introduced dip relaxation is for accommodating surface roughness and medium inhomogeneity. Third, the newly developed CS-based migration is modified and evaluated on GPR data from RC bridge decks. A more accurate model by accounting for impulse waveform distortion that leads to less modeling errors is proposed. The impact of the selection of the regularization parameter on the comparative amplitude reservation and the imaging performance is also investigated, and an approach to preserve the comparative amplitude information while still maintaining a clear image is proposed. Moreover, the potential of initially sampling the time-spatial data with uniform sampling rates lower than that required by traditional migration methods is evaluated.

Esta pesquisa propôs uma contribuição aos procedimentos de inspeção de pontes por meio de um plano de monitoramento de curta duração do comportamento dinâmico do tabuleiro de pontes rodoviárias de concreto com a utilização de receptores GPS de 100 Hz associado à diversas técnicas de filtragem de sinais. O estudo foi conduzido em uma ponte em serviço localizada na rodovia Fernão Dias (BR-381). O procedimento de inspeção proposto baseou-se no uso de dois sinais de satélites GPS, por meio da aplicação do Método Residual de Fase (MRF), e da análise temporal dos resíduos da dupla diferença de fase a partir da Fast Fourier Transform (FFT), Continuous Wavelet Transform (CWT), Passa-Faixa Chebyshev do Tipo I. A descrição do comportamento dinâmico do tabuleiro do vão central da ponte se deu por meio da extração dos valores de frequência e amplitude das deflexões verticais a partir dos dados GPS filtrados (resíduos), em três períodos de amostragem de 1 minuto. Os valores de frequência variaram de 0,5 Hz a 8 Hz nos três períodos de amostragens e também nos filtros FFT, CWT e Passa-Faixa Chebyshev do Tipo I. Os valores de amplitude de deslocamento vertical máximo ficaram em torno de 6 mm. Estes valores coincidiram com os valores de frequência e amplitude de deslocamento vertical registrados pela instrumentação clássica com acelerômetros, transdutores de deslocamento vertical, modelagem por elementos finitos e prova de carga estática e dinâmica realizadas sobre tabuleiro do vão central da ponte instrumentado. Por fim, pode-se afirmar que os procedimentos propostos, além de poderem ser utilizados como uma etapa preliminar de inspeção de tabuleiro de pontes rígidas possibilitaram a detecção de deslocamentos dinâmicos verticais milimétricos e suas frequências de vibração. / This research proposed a contribution for bridge inspection procedures at of a short-term monitoring plan of the dynamic behavior of the concrete road bridge with the use of 100 Hz GPS receivers associated with various signal filtering techniques. The study was conducted in the service bridge located on the highway Fernão Dias (BR-381). The procedure inspection proposed was based on the use of two satellite GPS signals, by applying the Phase Residual Method (PRM), and the temporal analysis of the residuals of the double difference phase from the Fast Fourier Transform (FFT), Continuous Wavelet Transform (CWT), Type I Chebyshev Band-Pass. The dynamic behavior of the central span of the bridge was described by extracting the frequency and amplitude values of the vertical deflections from the filtered GPS data (residues), in three sampling periods of 1 minute. The frequency values found ranged from 0.5 Hz to 8 Hz in the three sampling periods as well as in the FFT, CWT and Chebyshev Type I Band-Pass filters. The maximum vertical displacement peak values were around 6 mm. These values coincided with the vertical displacement and amplitude values recorded by the classical instrumentation with accelerometers, vertical displacement transducers, finite element modeling and static and dynamic load test performed on the central span deck of the instrumented bridge. Finally, it could affirm that the procedures proposed, besides being able to be used as a preliminary step of inspection of the rigid bridge\'s deck enabled the detection of millimetric vertical dynamic displacements and their frequencies of vibration.

Straßenbrücken im Bestand bilden einen beachtlichen Teil des Anlagevermögens der bundesdeutschen Verkehrsinfrastruktur. Diese existierenden Brücken stellen die verantwortlichen Behörden vor erhebliche Herausforderungen. Einen großen Anteil am Bestand nehmen Brücken in Spannbetonbauweise ein. Viele der heute noch existierenden Konstruktionen sind in der Zeit des wirtschaftlichen Aufschwungs nach den 1960er Jahren in der BRD entstanden. Die Spannbetonbauweise wurde parallel zur Anwendung erforscht und weiterentwickelt. Bestimmte Bauweisen und Bauverfahren bildeten sich heraus, die bis in die Gegenwart angewendet werden. Heute sind diese Brücken veränderten Anforderungen ausgesetzt. Ältere Brücken stehen unter immer höheren Belastungen. Die statische Nachrechnung ist ein Hilfsmittel für Ingenieure zur Beurteilung bestehender Brückenbauwerke. Im Jahre 2011 wurde dazu vom Bundesministerium für Verkehr, Bau und Stadtentwicklung eine Richtlinie zur Nachrechnung von Straßenbrücken herausgegeben. Erfahrungen und Ergebnisse in der Anwendung wurden veröffentlicht. Bei vielen Spannbetonbrücken wurden damit rechnerische Defizite ausgewiesen, die zu einer Einschränkung der weiteren Nutzungsdauer führen. Damit können solche Spannbetonbrücken nicht mehr so lange genutzt werden, wie ursprünglich geplant. Verantwortlich dafür kann u. a. der statische Nachweis der Dekompression sein, bei dem im Beton keine bzw. unter Anwendung der gegenwärtigen Fassung dieser Richtlinie nur sehr geringe Zugspannungen auftreten dürfen. Es werden Spannbetonbrücken betrachtet, die im Taktschiebeverfahren hergestellt wurden. Diese weisen bestimmte Konstruktionsmerkmale auf, sodass hauptsächlich allein der Nachweis der Dekompression noch maßgeblich für die Einschränkung der Nutzungsdauer sein kann. Die Grundlagen des Nachweises der Gebrauchstauglichkeit basierend auf dem bewährten Konzept der zulässigen Spannungen in der früheren deutschen Spannbetonnorm werden erläutert. Diese frühere Norm wird dem Konzept der europäischen Mustervorschrift (Model Code) bis zu den heute gültigen Eurocodes gegenübergestellt. Auf der Einwirkungsseite werden die früheren Lastfälle in das heute nach Eurocode gültige Konzept der Einwirkungskombinationen im Grenzzustand der Gebrauchstauglichkeit eingeordnet. Die Hintergründe der früher zulässigen Spannungen im Beton auf Zug auf der Widerstandsseite werden beschrieben. Die früheren Grenzwerte werden kritisch beurteilt. Es wird herausgearbeitet, dass die gegenwärtige Regelung der Richtlinie beim Nachweis der Dekompression zu ungünstig ist. Ein differenzierteres Nachweisverfahren auf Basis des Eurocodes wird vorgeschlagen. Damit soll die Verkürzung der Nutzungsdauer aufgehoben werden. Wenn sonst keine Einschränkungen bestehen, können mit diesem Vorschlag solche Spannbetonbrücken wenigstens solange genutzt werden, wie ursprünglich vorgesehen. Bei der Anwendung sind Einschränkungen zu beachten. Die Übertragung auf andere Bauweisen von Spannbetonbrücken wäre möglich.

The master´s thesis is about detailed design of highway bridge from prestressed concrete between the cities Brno and Ostrava. The construction is continuous and consists from three fields. Internal forces was taken from software SCIA Engineer. The static assessment was realized according to limit states. Counstruction is evaluated according to the current standards.

The purpose of the master thesis is the design of the concrete highway bridge by European standards. The highway is situated on two independent prestressed load-bearing structures with cross-section area of constant dimensions over its length. The bridge deck is built on a falsework considering its proportions and obstacles under the bridge. The thesis contains the design and the assessment of the load-bearing structure in longitudinal and transverse direction including the calculation of cross beams and an anchorage zone.

Europe experienced the destruction of numerous infrastructures during World War II, followed by a reflation and a strong economic growth during the next two decades allowing a more perennial and durable situation. A classical bridge lasting in general around 80 years, one should observe that these constructions built after the war will have to be either replaced either seriously strengthened in a few years. Besides, since the needs also vary over time, transportation infrastructures built during those years might not be adapted to the actual needs anymore – some bridges might thus have to be widened. A case study has been chosen in order to simulate under which conditions the widening of such a bridge can be performed. This road bridge, located in Vierzon in France, is rather simple since it is made of simply supported prestressed concrete beams and of reinforced concrete piers. It has been chosen in particular for its reduced size – three spans of 30 m each and two road lanes – that corresponded well to this project. Based on some data provided when the bridge was initially built and on a visual inspection, this project suggests six technical solutions to double the actual amount of lanes. An evaluation of the performance of the solutions according to three criteria – durations of works, cost of the works, and environmental impact – is made in order to give recommendations regarding the optimal solution. The results show that in spite of being installed quickly, adding steel beams is more expensive and has a greater impact on the environment than adding prestressed concrete beams. Regarding the modification of piers, the solution suggesting widening the existing piers is preferable than adding new extra piers according to all the criteria. Consequently, among all the solutions analysed, the optimal one is also the simplest one. Finally, the limits of the study and some suggestions for improvements are indicated.

Utsläpp av växthusgaser bidrar till global uppvärmning som är ett hot mot vårt klimat. Sveriges långsiktiga klimatmål är att inte ha några nettoutsläpp senast år 2045. Infrastrukturen står för en betydande del av klimatpåverkande utsläpp. Utsläppen från väg- och järnvägsbygge kommer mestadels från tillverkning av betong och stål som används för byggnation av broar samt andra byggnadsverk. Tillverkningen av cement, som är en viktig beståndsdel i betong, genererar koldioxidutsläpp som står för cirka 3–4 % av världens totala utsläpp. Syftet med studien är att undersöka klimatpåverkan från betongbroar och identifiera de poster som bidrar till störst klimatavtryck under produkt- och byggproduktionsskedet. Alternativa optimerade lösningar undersöks, vars tyngdpunkt läggs på att främja ett hållbart byggande av betongbroar. För att nå målet med studien har en fallstudie utförts på en plattrambro av betong över gång-och cykelväg. Fallstudien innehåller mestadels en livscykelanalys, som baserats på dokumentanalys, för att kunna identifiera var i produkt-och produktionsskedet de största klimatavtrycken sker. Utöver livscykelanalys utfördes intervjuer för att föreslå mer hållbara alternativ för en minskad klimatpåverkan. Livscykelanalys (LCA) innebär undersökning av en produkts eller tjänsts resurs- och miljökonsekvenser från vaggan till graven och baseras på SS-EN ISO 14000-serien. En byggnadsverks livscykel är indelad huvudsakligen i tre skeden: byggskede, användningsskede och slutskede. Byggskedet delas in i två underkategorier, produkt- och produktionsskedet. Resultatet från studien visade en total klimatpåverkan på 82 711 kg CO2e för produkt-och produktionsskedet, varav de största bidragande faktorerna var betongen och armeringen. Efter åtgärder, som innefattar byte av armeringstyp samt återanvänd fyllnadsmaterial, sänktes den totala klimatpåverkan med 8 244 kg CO2e. Alternativa lösningar som har föreslagits är stålfiberarmerad betong i kantbalkar, höghållfasthetsstål i broräcken, HVO som drivmedel samt framställning av biokol. Betongen ansågs vara lämplig utifrån ett hållbarhetsperspektiv då dess bidragande till koldioxidutsläpp var lägre i jämförelse med andra betongtyper på marknaden, vare sig klimatoptimerade eller konventionella. Armeringen byttes ut till en grönare och närproducerad armeringstyp för att främja miljövänligare materialval samt för att minska på klimatavtryck från transport. Vidare har det konstaterats att förnybara drivmedel är betydande för att reducera klimatpåverkan. För att reducera klimatavtrycket ytterligare kan höghållfasthetsstål i broräcke användas istället för galvaniserat stål. För att främja ett hållbart byggande bör det tas hänsyn till resursanvändning samt återanvändning. Innan återvinning, ska återanvändning ske i första hand i mån av skick och möjlighet för att minska på resursanvändningen. / The infrastructure accounts for a significant part of climate-affecting emissions. Emissions from road and railway construction come mostly from the production of concrete and steel used for the construction of bridges and other construction works. The purpose of the study is to investigate the climate impact from concrete bridges and identify the resources that contribute to the largest climate footprint during the material production and construction phase. Alternative optimized solutions are being investigated, whose emphasis is on promoting sustainable construction of concrete bridges. To achieve the goal of the study, a case study was conducted on an integral bridge of concrete. The case study mostly included a life cycle assessment, based on document analysis, in order to be able to identify where in the material production and construction phase the largest climate footprints occur. In addition to life cycle assessment, interviews were conducted to suggest more sustainable alternatives for a reduced climate impact. The results from the study showed a total climate impact of 82,711 kg CO2e from the product and production phase, of which the largest contributing factors were the concrete and the reinforcement. Improved solutions have been proposed in order to reduce the climate impact. The concrete that is used for the bridge was considered suitable from a sustainability perspective because its contribution to carbon dioxide emissions was lower compared to other types of concrete on the market. The reinforcement will be replaced with a greener and locally produced type of reinforcement to promote more environmentally friendly material choices and to reduce the climate footprint from transport. Furthermore, it has been established that renewable fuels are significant in reducing climate impact. To further reduce the climate footprint, high-strength steel in bridge railings can be used instead of galvanized steel. In order to promote sustainable construction, the use of resources should be taken into account.

The theme of the master’s thesis is detailed design bridge structure. The thesis is devoted to limit states assessment of the structure. The thesis includes a time analysis structure and a detailed solution influence of construction on its proposal.

No description available.