A pedestrian crowd walking on a footbridge causes the footbridge to vibrate. These vibrations become an issue of serviceability and can give rise to discomfort for the pedestrians, whereby they should, to as large extent as possible, be prevented. Currently, there is a lack of reliable models to describe a dynamic load on a footbridge, due to a walking crowd. Therefore, there is a need for such models. Lately, a great amount of research has been carried out on the subject pedestrian-induced vibrations of footbridges, though most of it with focus on lateral vibrations. Conversely, this project has been performed aiming to accurately model pedestrian-induced vertical vibrations of a general footbridge. For that purpose, starting from an existing model, a somewhat improved model, comprising three sub-model, has been developed. The sub-models are: one model of the pedestrian crowd walking along the footbridge, one model describing the load from the pedestrian footstep and one model describing the interaction between the pedestrians and the footbridge. In order to get statistically reliable results, numerous simulations of the pedestrian-induced vertical vibrations of a specific footbridge have been performed, using the developed model. Averaging the results over the simulations, we could conclude that the model gives an average error of 7 %, compared to experimental data. The measured quantity giving these results was the absolute maximum value of the acceleration at the midpoint of the footbridge. The achieved dynamical response of the footbridge is qualitatively satisfying, while the quantitative error is larger than we hoped for, whereby we conclude that further improvement of the model is needed before we are able to accurately model pedestrian-induced vertical vibrations of footbridges. / När en folksamling går över en gångbro uppstår vibrationer i gångbron. Dessa vibrationer påverkar brons användbarhet och kan ge upphov till obehagskänsla hos fotgängarna, vilket gör att vibrationerna i största möjliga utsträckning bör motverkas. I nuläget saknas pålitliga modeller för att beskriva den dynamiska last en gångbro utsätts för när en folksamling går över den. Således föreligger ett behov att utveckla en sådan modell. Under de senaste decennierna har mycket forskning utförts inom området människoinducerade vibrationer i gångbroar. Dock har merparten av denna forskning berört endast laterala vibrationer. Detta projekt däremot, har genomförts med syftet att, med ett noggrant resultat, modellera människoinducerade vertikala vibrationer i en generell gångbro. För att uppnå detta har jag utgått från en befintlig modell och från den utvecklat en ny modell bestående av tre delmodeller. De tre delmodellerna är: en modell som beskriver hur folksamlingen rör sig över gångbron, en modell som beskriver den kraft det mänskliga fotsteget uträttar på gångbron och en modell som beskriver interaktionen mellan fotgängarna och gångbron. För att uppnå statistiskt tillförlitliga resultat har modellen som utvecklats i detta projekt använts för att utföra åtskilliga simuleringar av människoinducerade vertikala vibrationer i en specifik gångbro. Om vi medelvärdesbildar resultaten över simuleringarna framgår det att modellen som utvecklats ger ett resultat som avviker med 7 % från experimentellt data. Detta gäller för den maximala accelerationen vid gångbrons mittpunkt. Den resulterande dynamiska responsen ser kvalitativt sett bra ut, medan den kvantitativa avvikelsen är större än vi hoppats på. Därför drar vi slutsatsen att vidare förbättringar av modellen behövs för att den ska kunna användas till att på ett noggrant sätt modellera människoinducerade vertikala vibrationer i gångbroar.

É inegável a importância do desenvolvimento de tecnologias de uso racional da madeira e de solução de problemas de transportes em nossas cidades, principalmente por causa do processo crescente de urbanização do mundo. Existe também, a necessidade estética de se unir à alta tecnologia, o belo. As passarelas estaiadas com tabuleiro de madeira laminada protendida, em módulos curvos, atendem a todas estas exigências. A construção de um protótipo permitiu que a realização de ensaios estáticos e dinâmicos, cujos resultados evidenciaram a viabilidade técnica e econômica de passarelas estaiadas usando madeira de reflorestamento, de tabuleiros compostos apenas por placas de madeira laminada protendida e da construção de placas curvas de madeira laminada protendida. Também foi possível comprovar que as vibrações induzidas por pedestres são a condição mais crítica de projeto. A investigação da perda de curvatura do tabuleiro demonstrou o sucesso do projeto, embora mais estudos ao longo do tempo sejam necessários. Baseando-se nos resultados experimentais, realizou-se a calibração do modelo numérico, que permitiu realizar simulações para determinar quais variáveis definem a resposta da passarela construída. Sugestões de procedimentos de elaboração e construção de passarelas, assim como de criação de norma brasileira específica para pontes e passarelas de madeira, são apresentadas. / The ongoing, worldwide, large scale urbanization is stressing more and more the importance of developing new technologies concerned with the rational use of timber and with the solution of transportation problems in cities. There is also an aesthetical need of showing the melting of up-to-date high technology with beauty. The cable-stayed stress laminated timber footbridge, with curved modules meets all these needs. The buildings of a prototype, enable static and dynamic tests to be carried out. The experimental results revealed the technical and economical feasibility of the following items: a) cable stayed footbridges with timber from reforestation, b) decks only made of stress laminated timber, c) curved plates of stress laminated timber. It also revealed that the human induced vibrations leads to the most critical design condition. The loss of deck curvature study indicated the need of further research considering the time effect, to confirm the initial sucess achieved. Based on the results of these testings, the calibration of the numerical model was done. In order to investigate which variables are responsible for the footbridge response, several simulations were performed with the calibrated model. Guidelines for design and building of timber footbridges are presented. The creation of a brazilian code for timber bridges and footbridges is also suggested.

É inegável a importância do desenvolvimento de tecnologias de uso racional da madeira e de solução de problemas de transportes em nossas cidades, principalmente por causa do processo crescente de urbanização do mundo. Existe também, a necessidade estética de se unir à alta tecnologia, o belo. As passarelas estaiadas com tabuleiro de madeira laminada protendida, em módulos curvos, atendem a todas estas exigências. A construção de um protótipo permitiu que a realização de ensaios estáticos e dinâmicos, cujos resultados evidenciaram a viabilidade técnica e econômica de passarelas estaiadas usando madeira de reflorestamento, de tabuleiros compostos apenas por placas de madeira laminada protendida e da construção de placas curvas de madeira laminada protendida. Também foi possível comprovar que as vibrações induzidas por pedestres são a condição mais crítica de projeto. A investigação da perda de curvatura do tabuleiro demonstrou o sucesso do projeto, embora mais estudos ao longo do tempo sejam necessários. Baseando-se nos resultados experimentais, realizou-se a calibração do modelo numérico, que permitiu realizar simulações para determinar quais variáveis definem a resposta da passarela construída. Sugestões de procedimentos de elaboração e construção de passarelas, assim como de criação de norma brasileira específica para pontes e passarelas de madeira, são apresentadas. / The ongoing, worldwide, large scale urbanization is stressing more and more the importance of developing new technologies concerned with the rational use of timber and with the solution of transportation problems in cities. There is also an aesthetical need of showing the melting of up-to-date high technology with beauty. The cable-stayed stress laminated timber footbridge, with curved modules meets all these needs. The buildings of a prototype, enable static and dynamic tests to be carried out. The experimental results revealed the technical and economical feasibility of the following items: a) cable stayed footbridges with timber from reforestation, b) decks only made of stress laminated timber, c) curved plates of stress laminated timber. It also revealed that the human induced vibrations leads to the most critical design condition. The loss of deck curvature study indicated the need of further research considering the time effect, to confirm the initial sucess achieved. Based on the results of these testings, the calibration of the numerical model was done. In order to investigate which variables are responsible for the footbridge response, several simulations were performed with the calibrated model. Guidelines for design and building of timber footbridges are presented. The creation of a brazilian code for timber bridges and footbridges is also suggested.

According to Joshua Greene’s dual-process theory, our moral judgments are processed in one of two systems in the brain referred to as the emotional (quick, unconscious) and rational (slow, conscious) system. The reason for why people tend to answer differently in the footbridge dilemma compared to the trolley dilemma is because the emotional system is dominating over the rational system. Research has demonstrated that patients with ventromedial prefrontal cortex damage make more utilitarian judgments in moral dilemmas in relation to harmful situations. According to the dual-process theory, this is because the emotional system has been impaired which results in that the only working system is the rational system. The aim of this thesis is to investigate how the dual-process theory tries to explain why our moral judgments tend to differ in some moral dilemmas. This thesis will also look at how the dual-process theory tries to explain why patients with ventromedial prefrontal cortex damage make utilitarian judgments in relation to harmful situations. This thesis will sustain that the dual-process theory have gained strong empirical support, especially from the research that has been made on patients with ventromedial prefrontal cortex damage. This thesis will also argue that some modifications needs to be made on the dual-process theory in order to make it stronger.

This thesis describes the design of steel structures footbridge over the track in Havířov. The total length of the bridge is 101.6 m footbridge consists of four parts. The basic structural system of the first part of the beam is solidified arc. Other parts are made girders. Free bridge width is 3.2 m Footbridge will be used to connect local area Havířov - Šumbark to the train station.

The aim of this master’s thesis is to design a footbridge across a river. The main objective is design and analysis of a footbridge supported by a steel arch. Stress ribbon is suspended on steel arch using hangers. The analysis of the structure has been carried out using ANSYS 12.0 and Nemetschek SCIA 2011.1 software, design checks using EXCEL in accordance with Eurocodes. Time dependent analysis was considered.

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 purpose of the thesis is to suggest a span enlargement of steel Modular footbridge ML36 for pedestrian and cycling transport. The aim is to preserve as many elements of the original construction as possible. In the thesis, three variants are discussed with the detailed focus on one of them. The chosen variant is made up by elongated original footbridge ML36, which is supported by prestressed structure. From the static point of view, it is a simply supported truss. The span of the footbridge is 39-45. The main material of the structural elements is steel S355, S460 and S520.

The diploma thesis is focused on a design and appraisal of a steel load bearing construction of footbridge. The footbridge builds a new bridge across the river Ostravice in Sviadnov at Frýdek-Místek. The main subject of the diploma thesis was preparation of three variants for the footbridge. All variants were evaluated and the best one was elaborated in depth. It is a footbridge with a total span of 57 metres with a load bearing construction created two arches bent down to each orther. There is an orthotropic bridge deck with main outer lenghthways girders on the arches.

Vibration serviceability in the design of footbridges is gathering enormous prominence as comfort restrictions get enhanced. Comfort verifications are often becoming critical when considering human induced dynamic loading on lightweight structures, which are increasing in slenderness and flexibility. The aim of this work was to build up understanding about the running load effects on the response of footbridges and proving that it could imply a critical load case that would require verification. Additionally, the accuracy of potential models to estimate the structural response was evaluated. Finally, aiming for a practical application, this work provides a step forward towards the possibility of adopting a simplified design methodology to be included in the future guidelines and an insight into the potential effects of a marathon event. While the walking load case is a well-studied phenomenon, not much attention has been paid to the running induced excitation. Guidelines motivate that there is no need for verification and exceptionally, some get to suggest a time domain load model definition. The interaction phenomena as well as the effects of groups of runners in the dynamic response of the structure remain still unknown. Limiting the work to the vertical component of the response and force and based on a large set of additional assumptions, experimental and numerical analyses were performed. Three footbridges were tested and subjected to tests involving different motion forms; jumping, walking and running. On the other hand, the time domain load models available in the literature were applied accounting for the spatial displacement of each of the pedestrians along the footbridge. In the most advanced of the models, aiming to account for interaction effects, the subjects were modelled as independent mechanical systems. The results derived from the experimental study helped characterizing the running load effect on the footbridge's response and proved that there may be structures in which running could comprise a critical load case. Furthermore, the numerical analyses allowed to verify the accuracy of the suggested models and the improvement that the human structure interaction effects involve. The analyses resulted in complementary sets of conclusions that built up understanding about the running load effects on footbridges; such as the sensitivity of the estimated response to the structure's modal properties and the influence of the parameters that characterize the running motion. Finally, the suggested simplified design methodology was able to estimate, with a very reasonable error for the current case study, the calculated response by the most accurate of the models. To sum up, this work serves as a motivation to include the running load case in the guidelines and establishes a starting point for further research and simplified design methodologies based on the strategy and models suggested in this work.