Este trabalho apresenta o desenvolvimento de metodologia para avaliar a utilização do Sistema de Posicionamento Global (GPS) como ferramenta de pesquisa no estudo do comportamento dinâmico de obras viárias. Para ser caracterizado como um instrumento de medição, foi estudada a potencialidade de um método, que se fundamenta numa forma específica de coleta e processamento de dados GPS; análise dos resíduos resultantes do processamento da dupla diferença de fase e aplicação de análise espectral para filtragem de informações indesejáveis (multicaminhamento dos sinais GPS). A coleta envolve um oscilador eletro-mecânico, especialmente projetado, que permite calibrar as medidas de amplitude e freqüência das oscilações mensuráveis pela obra sob teste. Inúmeros experimentos foram realizados em ambientes de reflexões e difrações variáveis e com diversos tipos de receptores e antenas GPS. Alguns ensaios foram realizados utilizando, simultaneamente, equipamentos como transdutores de deslocamento, acelerômetros e estações totais. Comparando os resultados obtidos, mesmo com valores prescritos em normas e códigos, afirma-se que o GPS, sob o método de coleta de dados testado, é um instrumento confiável para detecção e caracterização do comportamento dinâmico de estruturas, apresentado confiabilidade para as medições realizadas, da ordem de décimos de milímetro. Quanto à detecção das freqüências, as mais baixas ficam comprometidas pela presença do multicaminhamento e as mais elevadas têm a detecção limitada pela máxima taxa de coleta dos receptores (Lei de Nyquist) / This work presents the development of a methodology to appraise the use of Global Positioning System (GPS) as a tool for researching of dynamic behavior of road transport structures. To be characterized as an instrument for measuring it was studied the potentiality of one method which includes a specific mode of GPS data collection; analyses of double difference phase residuals and application of spectral analyses and filtering for excluding undesirable information (multipath). The GPS data collected applies an electro-mechanical oscillator, specially built for that, which permits to calibrate the measures of frequency and amplitude of structure’s oscillations under dynamic load test. Several field tests were carried out in vicinities with high and low capacity of causing signal reflections and diffractions and with different types of GPS receivers and GPS antennas. A couple of fields were carried out using, at the same time, transducers of displacement, accelerometers and total stations. Comparing these results obtained even with values of codes, it is affirmed that GPS, under the data collection method tested, it is a trustworthy instrument for detection and characterization of dynamic behavior of structures, presenting reliability of measures ranging around tenths of millimeters. The very low frequencies are highly degraded by multipath and very high frequencies have its detection limited by the receiver data rate (Theorem’s Nyquist)

Cette thèse s'inscrit dans la continuation du travail de Younes Achkire, consacré au contrôle actif des ponts haubanés. Elle traite de l'implémentation d'un système de contrôle actif sur des maquettes de structures câblées. Deux types de structures sont étudiés expérimentalement: les ponts haubanés et les treillis spatiaux. Après une brève introduction sur l'usage du contrôle actif dans ces domaines, le chapitre 2 traite numériquement des mécanismes d'interaction entre le câble et la structure. Au chapitre 3, nous présentons la stratégie de contrôle que nous utilisons pour stabiliser une structure câblée: il s'agit d'un contrôle décentralisé, basé sur des paires capteur/actionneur colocalisées, placées au niveau des ancrages des câbles, chacune équipée d'un contrôleur Intégral Force Feedback. Nous présentons une théorie linéaire simplifiée permettant de dimensionner le système et de prévoir son efficacité. Elle est illustrée sur un exemple, et nous discutons de la validité de certaines hypothèses simplificatrices. Le chapitre 4 est consacré au contrôle actif des ponts haubanés. Nous y présentons 2 maquettes. La première, de petite taille (3m) représente un pylône de pont haubané en construction. Elle est équipée d'actionneurs piézoélectriques. La seconde, installée au Centre Commun de Recherche d'Ispra (Italie), mesure 30m de long, et est équipée d'actionneurs hydrauliques. Les expériences réalisées sur ces maquettes ont démontré l'efficacité du contrôle et la fiabilité de la théorie prédictive. Le contrôle du flottement des ponts est traité sur un exemple numérique. Le chapitre 5 relate nos expériences d'amortissement actif des treillis spatiaux. Deux structures ont été étudiées: une colonne en treillis équipée de 3 câbles actifs, et une structure triédrique suspendue à des cordons élastiques pour simuler l'absence de gravité, également munie de câbles actifs. Deux concepts d'actionneur piézoélectrique ont été testés. Nous avons ensuite examiné le problème de la saturation des actionneurs, et celui du contrôle actif des microvibrations (~10nm) d'une structure câblée. Le chapitre 6 conclut ce travail, en souligne les aspects originaux et donne quelques perspectives de développement. / Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished

The finite strip method (FSM) is a very efficient numerical method employed for performing the structural analysis of slender structures, such as cable-stayed bridges; the strip discretization of the model allows for the usage of a lower number of degrees of freedom, in comparison with the finite element method (FEM), while, as it will be discussed in the current research, the results obtained from both methods are in relatively good agreement. Moreover, to address the latest developments in the area of smart construction materials used for long-span bridges, the fiber reinforced polymer (FRP) composites were implemented for the bridge deck modeling, as part of a hybrid composite FRP cable-stayed bridge, and an extend laminate integrated finite strip method (LFSM) was applied for estimating the static structural performance of the hybrid composite FRP long-span cable-stayed bridge under several concentrated and uniformly distributed loadings. The free vibrations analysis was conducted for the Kap Shui Mun Cable-stayed Bridge model, and the natural frequencies were compared with the ones obtained from an FE model of the same bridge. One of the advantages of using the integrated finite strip method is that number of vibration modes, which can be included in the dynamic analysis when the effect of a sweeping sinus and a seismic loading are investigated when a conventional FE analysis would fail to converge. The outcomes of this research will set the stage for the hybrid long-span cable-stayed bridges modeling by the laminate integrated finite strip method (LFSM) which is more efficient and straightforward than the finite element analysis, for performing the static, free vibration, time domain, and frequency domain analyses.

This thesis deals with structural design of a steel frame footbridge with wheelchair access, which will lead pedestrian and cyclists‘ traffic over the river Thaya in Břeclav. The footbridge is a structure of one field, lightness of a bridge opening is 58,92 m and a span length is 60,25 m. A light width of an area between rails is 2,5 m. The footbridge is constructed of a truss beam cable – stayed bridge on an oblique pylon of 20,0 m length and a preloaded steel suspender. The thesis was processed according to valid standards ČSN EN.

The thesis deal with structural design of steel footbridge for pedestrians and cyclist over the Bečva river in Černotín village. Span of the footbridge is 50 m. The basic material is steel S355 and S460. At the beginning were created two variants. First one is an arched footbridge and the second one is cable stayed footbridge. After evaluation variants was selected the cable stayed footbridge. The selected variant was assessed in detail including joints and bearings. Structure is designed in compliance with valid standards of ČSN EN and corresponds with ultimate and serviceability limit state. For structural design was used software RFEM 5.17.01 of Dlubal company.

The aim of this master thesis is a design of the pedestrian bridge across the highway. The bridge is formed by a slab structure of 6 spans with lenghts from 9 to 51 m. The main spans are suspended on a V shape pylon. The deck of the span across the highway is assambled of precast segments and composite deck slab. The deck is in the lenghtways kept in the parabolic arch. The model of the construction is made in software ANSYS, the solution was done non-linear. The design and assessment are according to the europien standard.

The objective of this diploma thesis is a dynamic analysis of a cable-stayed walkway. The RFEM structural analysis software is used for the calculation. Design principles of the structure are explained and analysis of the construction phases is then performed. The eigenmodes of the structure are calculated for various material combinations. The thesis examines the effects of moving loads and earthquake effects using several different methods. A comparison of the various loading effects on the structure and also the calculation methods is presented at the conclusion.

In my thesis, I created a study of plan curved cable stayed pedestrian bridge. As the main construction material is used prestressed concrete. Suspenders and railing are made from steel. The footbridge has a length of 130,00 meters and a width of 3,70 meters. The plan shape of the structure is composed of two oposite arches. Bridge deck is made of box girder. The bridge deck is single-side suspended on two concrete pylons with a height of 39,00 m. Pylons are supported by suspender.

This diploma thesis aims to design a structure of pedestrian bridge over the Svratka river. To make a preliminary study of possible bridging, three different outlines were drafted. The cable-stayed variant was selected for further analysis. Two towers, inclined in both their longitudinal and transverse direction, support a cast-in-place post-tensioned concrete deck through stay cables anchored in the tower and the deck. After determining the desired initial state, a finite element analysis was carried out using the Ansys software. The capacity of all main load-bearing elements was checked so it meets the ULS and SLS design criteria in accordance with EN 1992 codes.

The content of the diploma thesis is design urban bridge in Považská Bystrica. From three possible options was selected one, which represents cable stayed bridge-extradosed with four spans. This selected option was elaborated in detail in this diploma thesis. Design procedures and assessments were performed to comply with ultimate limit state and serviceability limit state according to valid europeans standarts. The calculation model was performed in program Midas Civil in logitudinal axis and in SCIA Engineer in transversal axis. Structural assessment were done manually. The part of the diploma thesis are detailed drawings and visualizations.