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1
Claff, Daniel E. "Pedestrian-induced lateral excitation of footbridges." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:52927335-c9ae-4579-8c0c-d66e9b0074af.
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This thesis investigates human-structure interactions between pedestrians and oscillating footbridges via experimental kinematic and kinetic tests. The first aspect was to improve and validate a simple frontal plane gait model, the Inverted Pendulum Model (IPM), based on kinematic and kinetic gait data for stable ground walking. Next, test subjects were recorded while crossing a laterally swaying footbridge in order to examine kinematic and kinetic walking patterns and assess the model's accuracy at predicting unstable gait. Participants were recorded walking over force plates in a gait laboratory so their normal ground forces could be compared to each other and the IPM. High inter-subject variability and low intra-subject variability were observed. The IPM did not reproduce transient components of the ground forces. An analysis of the IPM's inherent assumptions revealed that some were inappropriate. A Modified Inverted Pendulum Model (MIPM) is proposed, eliminating some of the IPM's assumptions. For all samples examined, the correlation between the real ground forces and the MIPM was higher than that of the IPM. Custom-designed force plates were installed into a novel laboratory footbridge rig. The footbridge was excited naturally by the participants' walking and the participants responded naturally to the swaying of the bridge. The participants' step widths could be predicted by the phase of the structure at the previous heel strike. At high structural amplitudes, CoP and ground force patterns were dominated by the motion of the structure. Centre of Mass (CoM) motion was found to be 'fixed-in-space' with patterns dissimilar to those anticipated by the IPM. The MIPM was typically better than the IPM at predicting ground forces on the moving base. Finally, a spherical model was compared to the two-dimensional MIPM. The model exhibited few discrepancies to the spherical kinematic data, but the predicted medial-lateral ground forces were significantly different to the force plate data.
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Zäll, Emma. "Modelling Pedestrian-Induced Vertical Vibrations of Footbridges." Thesis, Umeå universitet, Institutionen för fysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-101831.
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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.
3
FAN, YINA, and FANGZHOU LIU. "Dynamic Analysis of Long Span Footbridges." Thesis, KTH, Bro- och stålbyggnad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-169183.
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A footbridge in Slussen is planned to be built and will connect the area of Gamla Stan with Sodermalm. As an increasing number of footbridges with large span tend to become more flexible and light these days, the corresponding dynamic problems due to decreased stiffness and mass draw much more attention. Specifically speaking, reduced stiffness and mass lead to smaller natural frequencies, which make the structure more sensitive to pedestrian-induced loading, especially in lateral direction. Fortunately, in this master thesis, only the vibration in vertical direction is focused due to that the footbridge in Slussen project uses enough lateral bracings to make sure that the safety of lateral vibration is kept at an acceptable level. In order to analyze dynamic response of the footbridge, the real footbridge structure is converted into a FE model by the commercial software LUSAS. In this thesis, four different kinds of critical standards are introduced, which are Sétra [8], Swedish standard Bro 2004 [9], ISO 10137 [5] and Eurocode respectively. By comparing these four criteria, Sétra and Eurocode are finally chosen to be the standard and guidelines for this project. They give the basic theories about how to model the pedestrian loading and provide critical values to check the accelerations in both vertical and lateral direction. By using FE software LUSAS, natural frequencies of the footbridge and the corresponding mode shapes can be calculated directly. Then, according to these results and relevant theories introduced by Sétra, the pedestrian loading can be modeled and the acceleration response of any specific mode can be obtained as well. Finally, based on the worst case with excessive acceleration, the methods to reduce dynamic response will be presented. Commonly, there are two ways to reduce acceleration response. One method is to increase the stiffness of the structure. However, the increased stiffness is always accompanied with increased mass of the structure. Because of this reason, the other way that installing dampers is widely used in recent years. In this thesis, the tuned mass dampers (TMDs) are introduced in detail as well as the information about the design principles of it. With important parameters known, TMDs can be added to the model to check how the accelerations can be reduced.
4
Pimentel, Roberto Leal. "Vibrational performance of pedestrian bridges due to human-induced loads." Thesis, University of Sheffield, 1997. http://etheses.whiterose.ac.uk/3447/.
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The vibrational performance of footbridges due to human-induced loads has been investigated, based on modal and pedestrian tests carried out on three prototype footbridges. Analyses using calibrated finite element models of these structures were also conducted. All test structures presented natural frequencies within the range of excitations produced by pedestrians and were therefore suitable for investigating the applicability of some current guidelines for vibration performance. In addition, the inclusion of a footbridge made of glass reinforced plastic in the test programme enabled the performance of this new type of footbridge construction to be investigated. The techniques of ambient excitation, impulse response using an instrumented hammer, and free-vibration decay were employed to obtain the modal properties of the test structures. The practicalities of using these techniques are discussed and improvements in their application are suggested. Very good agreement was obtained between the experimental and the numerical results. The calibrated numerical models were employed to investigate ways of removing the natural frequencies of the structures from the common range of pedestrian excitation, thereby improving their vibration performance. The handrails were identified as a potential way to increase the stiffness and thus the natural frequencies of a structure. In addition, use of a catenary shape or pre-camber in combination with horizontal restraint at the bearings were also shown to be useful for increasing natural frequencies since beneficial axial effects are introduced. In the case of the glass reinforced plastic footbridge, it was shown that a selective distribution of mass that could be conveniently added within the cells of the deck was the best strategy for frequency tuning. Guidelines for vibration performance are suggested, focusing on the definition of the pedestrian load and frequency ranges of interest, acceptability limits to vibration, treatment of multi-frequency component vibrations and vandal loading.
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Huang, Ming-Hui. "Dynamic characteristics of slender suspension footbridges." Queensland University of Technology, 2006. http://eprints.qut.edu.au/16450/.
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Due to the emergence of new materials and advanced engineering technology, slender footbridges are increasingly becoming popular to satisfy the modern transportation needs and the aesthetical requirements of society. These structures however are always "lively" with low stiffness, low mass, low damping and low natural frequencies. As a consequence, they are prone to vibration induced by human activities and can suffer severe vibration serviceability problems, particularly in the lateral direction. This phenomenon has been evidenced by the excessive lateral vibration of many footbridges worldwide such as the Millennium Bridge in London and the T-Bridge in Japan. Unfortunately, present bridge design codes worldwide do not provide sufficient guidelines and information to address such vibrations problems and to ensure safety and serviceability due to the lack of knowledge on the dynamic performance of such slender vibration sensitive bridge structures. A conceptual study has been carried out to comprehensively investigate the dynamic characteristics of slender suspension footbridges under human-induced dynamic loads and a footbridge model in full size with pre-tensioned reverse profiled cables in the vertical and horizontal planes has been proposed for this purpose. A similar physical suspension bridge model was designed and constructed in the laboratory, and experimental testings have been carried out to calibrate the computer simulations. The synchronous excitation induced by walking has been modelled as crowd walking dynamic loads which consist of dynamic vertical force, dynamic lateral force and static vertical force. The dynamic behaviour under synchronous excitation is simulated by resonant vibration at the pacing rate which coincides with a natural frequency of the footbridge structure. Two structural analysis software packages, Microstran and SAP2000 have been employed in the extensive numerical analysis. Research results show that the structural stiffness and vibration properties of suspension footbridges with pre-tensioned reverse profiled cables can be adjusted by choosing different structural parameters such as cable sag, cable section and pretensions in the reverse profiled cables. Slender suspension footbridges always have four main kinds of vibration modes: lateral, torsional, vertical and longitudinal modes. The lateral and torsional modes are often combined together and become two kinds of coupled modes: coupled lateral-torsional modes and coupled torsionallateral modes. Such kind of slender footbridges also have different dynamic performance in the lateral and vertical directions, and damping has only a small effect on the lateral vibration but significant effect on the vertical one. The fundamental coupled lateral-torsional mode and vertical mode are easily excited when crowd walking dynamic loads are distributed on full bridge deck. When the crowd walking dynamic loads are distributed eccentrically on half width of the deck, the fundamental coupled torsional-lateral mode can be excited and large lateral deflection can be induced. Higher order vertical modes and coupled lateral-torsional modes can also be excited by groups of walking pedestrians under certain conditions. It is found that the coupling coefficient introduced in this thesis to describe the coupling of a coupled mode, is an important factor which has significant effect on the lateral dynamic performance of slender suspension footbridges. The coupling coefficient, however, is influenced by many structural parameters such as cable configuration, cable section, cable sag, bridge span and pre-tensions, etc. In general, a large dynamic amplification factor is expected when the fundamental mode of a footbridge structure is the coupled lateral-torsional mode with a small coupling coefficient. The research findings of this thesis are useful in understanding the complex dynamic behaviour of slender and vibration sensitive suspension footbridges under humaninduced dynamic loads. They are also helpful in developing design guidance and techniques to improve the dynamic performance of such slender vibration sensitive footbridges and similar structures and hence to ensure their safety and serviceability.
6
Garmendia, Purroy Javier. "Serviceability assessment of footbridges when subjected to vibrations induced by running pedestrians." Thesis, KTH, Bro- och stålbyggnad, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210930.
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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.
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Husebo, Jon F. "The search for a sculptural paradigm: the design of a pedestrian bridge." Thesis, Virginia Polytechnic Institute and State University, 1992. http://hdl.handle.net/10919/53321.
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Výborný, Martin. "Lávka přes řeku Úpu v Trutnově." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227860.
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The goal of this thesis was to design a steel structure of a footbridge for pedestrians and cyclists over the river Úpa in Trutnov spanning 20m. Also, it was calculated with a crossing of 3,5t vehicle. Preliminary design was carried for two variants. Variant B is truss structure, structure of Variant A is carried by prestressed cable and is further developed. Main structural beams of variant A are designed to be a shape of parabole with the middle beam connected by arbitrary profiled vertical beams to supporting prestressed high yield cable. For the design of structure, SLS was the main factor so elastic check is performed for ULS.
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Hallak, Neilson John Peter. "Numerical and experimental dynamic analyses of the Vega Pedestrian bridge including seasonal effects." Thesis, KTH, Bro- och stålbyggnad, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-255536.
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As timber structures become increasingly relevant and sought after – since they enable improvements in building time while reducing a structure’s life cycle impacts – streamlining their design can have meaningful economic and environmental implications. For timber footbridges, its design is frequently governed by serviceability criteria linked to excessive vibrations. To address this in design, it is necessary to correctly characterize the structure’s dynamic properties and understand what the leading parameters in its behaviour are. This thesis studied an existing timber arch footbridge, aiming to evaluate its dynamic behaviour both with experimental measurements and with theoretical models. The influence of temperature change over different seasons was considered, particularly around its effect on the asphalt layer – whose stiffness is highly correlated to temperature. The experimental results showed high correlation between temperature and natural frequencies: a variation of +21°C reduced the natural frequency for the 1st transverse mode of the deck by as much as 30.6% while the 1st vertical mode was reduced by 17.7% (variation of 0.029Hz/°C). The damping ratio was also measured, though a definitive correlation between its value and temperature was not identified. This change in behaviour cannot be explained by the influence of the asphalt layer alone however, as there is a high degree of uncertainty around many other components of the bridge and their interactions, such as the connections. Thus, to fully characterize the influence of each component with changing temperature, further experimental tests would have to be performed, or simpler structures with fewer connections should be considered. In designing a new structure, considering the asphalt layer as an added mass is a straightforward way to treat this material at the most critical condition (i.e. no contribution to stiffness). This strategy lead to sufficiently similar results between the computational model and the experimental results at warm temperatures. The asphalt stiffness could perhaps be considered for the 1st transverse mode of the deck, since it is in this mode that the asphalt layer plays its largest contribution.
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Rotmeyer, Juliana Adele. "Publicness of elevated public space in Central, Hong Kong: an inquiry into the publicness of elevated pedestrian walkway systems asplaces and non-places." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B47300292.
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The transformation of Hong Kong into a high-density city has created a unique three-dimensional
urban fabric defined through networks of urban activity and infrastructure within
tight spatial constraints of mountainous slopes and the island shoreline. In Hong Kong urban
development, the government performs a dual role both as landlord and as administrator
determining the development agenda. With limited space available for development high
land price policies have restricted land supplies and priority is given to ‘economic space’
rather than ‘life space’. This has created a city of mobility based on consumption where
privatized public spaces such as shopping malls, corporate plazas and elevated walkways are
linked primarily to promote shopping. Public spaces are increasingly managed by private
parties, and the degree of publicness of such spaces is often not clearly distinguishable to
their potential users. Due to Hong Kong’s population density of approximately 33,000
persons/km2, practices of everyday life are increasingly limited by multiple restrictions
controlling the use of spaces that only seem to be public.
The district of Central, Hong Kong features an urban network of both publicly and privately
maintained elevated pedestrian walkways that provide a secondary circulation space.
Designed according to commercial priorities, the walkway system in Central typically links
privately owned second floor lobbies with similar owners to promote consumption. Although
these regulated spaces are required to allow public access 24 hours a day, pedestrian
connectivity seems merely an after thought. In such private public spaces, pedestrians move
between consumption nodes through a maze of displays and windows filled with luxury
consumer goods. This study takes focus on the walkways in Central thus investigating
publicness specifically within the context of Hong Kong's high-density urban fabric, then
within a wider context of elevated pedestrian walkway systems in Asian Pacific cities. To
this end, this thesis employs an empirical case study methodology consisting of a series of
observational studies. Each of these studies publicness transcribed through observations of
use, users and use patterns. This study identifies a distinction that underlies the discussion of
publicness: that of non-place as opposed to place. The distinction of space and place relates
to whether users establish personal relationships to the spaces they use and has drawn much
critical attention in urban studies over the past several decades. Places typically provide the
stage for social practices. The relationship between place and mobility at an elevated level
has however, not been studied in detail yet. As mobile urban populations pass through places
more than we dwell in them, a new type of space has emerged to facilitate a ‘frictionless
passage’, or non-place. Within this realm of non-place pedestrians pass through zones of
movement like passengers experiencing a lack of relationship or disconnectivity with a space.
This leads to the question whether elevated pedestrian walkways consisting of spatial flows,
movement and transitional zones are only capable of performing as non-places? Can
relationships develop between the walkways and their users, making them more than non-places,
but places?
A case study forms the main part of this thesis and specifically focuses on observing aspect of
movement and circulation within Central that determine perceptions of publicness. Findings
resulting from this study provide an understanding of the ambiguous nature of spaces in
Central. From a background study of elevated pedestrian walkways in six Asian Pacific
cities, indicators of publicness are established that provide a framework to distinguish
characteristics of elevated pedestrian walkways. In Central, gatherings among domestic
helpers are found to contribute to the success of the elevated pedestrian walkway system into
urban context. Results of this study indicate that elevated pedestrian walkways can be both
places and non-places depending on the publicness of space and suggest how a transition of
publicness can occur within such spaces.published_or_final_version
Architecture
Doctoral
Doctor of Philosophy
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Araújo, Junior Moacir Carlos. "Avaliação experimental da sincronização por densificação de grupos de pedestres em passarelas." Universidade Federal da Paraíba, 2008. http://tede.biblioteca.ufpb.br:8080/handle/tede/5559.
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Footbridges are special works of art, present in large urban centers and along the highways. They are built above the roads to improve the safety of pedestrians and facilitate the flow of traffic, since they eliminate the points of conflict between pedestrians and vehicles. The occurrence of the phenomenon lock-in has implied the closing for repair of footbridges subject to dynamic loading induced by crowds of walking pedestrians. This is because the synchronization between the movement of pedestrians and the displacement of the structure has resulted in the occurrence of excessive vibration, when the frequency of excitation generated due to walking is close to the natural frequency of the footbridge. Despite several works about the lock-in, little has been concluded to try to develop a mathematical model to represent the onset of the phenomenon. In principle, another type of synchronization, which occurs among pedestrians, due to densification in crowd situations, would start rising vibrations in the structure, initiating the lock-in. However, there is a lack of experimental data in the literature to prove that theory. An experimental study on the synchronization between pedestrians due to densification was carried out in this research. Experimental tests were conducted on a prototype footbridge with different densities of pedestrians. For the densities investigated (0,3, 0,7 and 0,9 pedestrians/m²) with the pedestrian walking with their natural pacing rate, no evidence of synchronization was found. Tests were also conducted with induced pacing rate, to check the robustness of the methodology used. The results showed that the procedure adopted was valid and can be applied to other densities of interest.
As passarelas são obras de arte especiais, presentes nos grandes centros urbanos e ao longo das rodovias. Tratam-se de travessias em desnível construídas para aumentar a segurança dos pedestres e facilitar o fluxo de tráfego, já que eliminam os pontos de conflito entre pedestres e veículos. A ocorrência do fenômeno lock-in tem levado à interdição para reparos passarelas sujeitas ao carregamento dinâmico induzido por multidões de pedestres ao caminhar. Isso porque a sincronização entre o movimento dos pedestres e os deslocamentos da estrutura tem resultado na ocorrência de vibrações excessivas, nos casos em que a freqüência de excitação produzida pelo caminhar dos pedestres se aproxima da freqüência natural da passarela. Apesar de diversas pesquisas a respeito do lock-in, os resultados ainda são escassos para embasar o desenvolvimento de modelos matemáticos que representem o fenômeno. A princípio, um outro tipo de sincronização, que ocorre entre pedestres em situações de multidão, devido à densificação, daria início às vibrações na estrutura que originariam o lock-in. Contudo, faltam na literatura dados experimentais que comprovem essa teoria. Um estudo experimental a respeito da sincronização entre pedestres devido à densificação foi feito nesta pesquisa. Testes experimentais foram realizados num protótipo de passarela com diferentes densidades de pedestres. Para as densidades investigadas (0,3, 0,7 e 0,9 pedestres/m²), com os pedestres caminhando com sua taxa de passo natural, nenhum indício de sincronização foi verificado. Também foram realizados testes com taxa de passo induzida para verificar a robustez da metodologia utilizada. Os resultados mostraram que o procedimento adotado é válido e pode ser aplicado para outras densidades de interesse.
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Debona, Gilvan Lunz. "Modelagem do comportamento dinâmico de passarelas tubulares em aço e mistas (aço-concreto)." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=3419.
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Fundação de Amparo à Pesquisa do Estado do Rio de JaneiroA experiência dos engenheiros estruturais e os conhecimentos adquiridos pelo uso de materiais e novas tecnologias, têm ocasionado estruturas de aço e mistas (aço-concreto) de passarelas cada vez mais ousadas. Este fato tem gerado estruturas de passarelas esbeltas, e consequentemente, alterando os seus estados de limite de serviço e último associados ao seu projeto. Uma consequência direta desta tendência de projeto é o aumento considerável das vibrações das estruturas. Portanto, a presente investigação foi realizada com base em um modelo de carregamento mais realista, desenvolvido para incorporar os efeitos dinâmicos induzidos pela caminhada de pessoas. O modelo de carregamento considera a subida e a descida da massa efetiva do corpo em cada passo. A posição da carga dinâmica também foi alterada de acordo com a posição do pedestre sobre a estrutura e a função do tempo gerada, possui uma variação espacial e temporal. O efeito do calcanhar do pedestre também foi incorporado na análise. O modelo estrutural investigado baseia-se em uma passarela tubular (aço-concreto), medindo 82,5m. A estrutura é composta por três vãos (32,5 m, 20,0 m e 17,5 m, respectivamente) e dois balanços (7,5 m e 5,0 m, respectivamente). O sistema estrutural é constituído por perfis de aço tubular e uma laje de concreto, e é atualmente utilizada para travessia de pedestres. Esta investigação é realizada com base em resultados experimentais, relacionando a resposta dinâmica da passarela com as obtidas via modelos de elementos finitos. O modelo computacional proposto adota as técnicas de refinamento de malha, usualmente presente em simulações pelo método de elementos finitos. O modelo de elementos finitos foi desenvolvido e validado com resultados experimentais. Este modelo de passarela tubular permitiu uma avaliação dinâmica completa, investigando especialmente ao conforto humano e seus limites de utilização associados à vibração. A resposta dinâmica do sistema, em termos de acelerações de pico, foi obtida e comparada com os valores limites propostos por diversos autores e padrões de projeto. As acelerações de pico encontradas na presente análise indicou que a passarela tubular investigada apresentou problemas relacionados com o conforto humano. Por isso, foi detectado que este tipo de estrutura pode atingir níveis de vibrações excessivas que podem comprometer o conforto do usuário na passarela e especialmente a sua segurança.
The structural engineers experience and knowledge allied by the use newly developed materials and technologies have produced steel and composite (steel-concrete) footbridges with daring structures. This fact have generated very slender structural footbridges and consequently changed the serviceability and ultimate limit states associated to their design. A direct consequence of this design trend is a considerable increase of structural vibrations. Therefore, the present investigation was carried out based on a more realistic load model developed to incorporate the dynamic effects induced by people walking. The load model considered the ascent and descending movement of the human body effective mass at each step. The position of the dynamic load was also changed according to the individual position and the generated time function, having a space and time description. The effect of the human heel was also incorporated in the analysis. The investigated structural model was based on a tubular composite (steel-concrete) footbridge, spanning 82.5 m. The structure is composed by three spans (32.5 m, 17.5 m and 20.0 m, respectively) and two overhangs (7.5 m and 5.0 m, respectively). The structural system is constituted by tubular steel sections and a concrete slab and is currently used for pedestrian crossing. This investigation is carried out based on correlations between the experimental results related to the footbridge dynamic response and those obtained with finite element models. The proposed computational model adopted the usual mesh refinement techniques present in finite element method simulations. The finite element model has been developed and validated with the experimental results. This model enabled a complete dynamic evaluation of the investigated tubular footbridge especially in terms of human comfort and its associated vibration serviceability limit states. The system dynamic response, in terms of peak accelerations, was obtained and compared to the limiting values proposed by several authors and design standards. The peak accelerations found in the present analysis indicated that the investigated tubular footbridge presented problems related with human comfort. Hence it was detected that this type of structure can reach high vibration levels that can compromise the footbridge users comfort and especially its safety.
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Feitosa, Fábio Faria. "Análise dinâmica de passarelas de pedestres mistas (açoconcreto)com aberturas na alma das vigas de aço." Universidade do Estado do Rio de Janeiro, 2012. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=7836.
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Limitações de altura têm sido impostas sobre edificações por regulamentos de
zoneamento urbano e aspectos econômicos e estéticos. Além disso, para se
proporcionar a passagem de tubulações de grande diâmetro sob vigas de aço, um
pé-direito alto é normalmente requerido. Uma solução frequentemente utilizada em
projeto diz respeito à abertura de furos na alma das vigas de aço para passagem
das tubulações de serviço. Assim sendo, este trabalho de pesquisa objetiva a
avaliação da resposta dinâmica de passarelas para pedestres, onde o projeto
estrutural prevê a utilização de vigas celulares em aço. Objetiva-se verificar a
influência das aberturas nas almas dessas vigas sobre a resposta dinâmica das
passarelas. As ações dinâmicas representativas do caminhar dos pedestres são
simuladas por meio de um modelo matemático que considera uma descrição
espacial e temporal e, ainda, inclui o efeito do impacto do calcanhar humano. Os
modelos estruturais investigados correspondem a passarelas mistas (aço-concreto)
com 10m a 30m de extensão. São empregadas técnicas usuais de discretização, via
método dos elementos finitos, por meio do programa Ansys. A resposta dinâmica das
passarelas é obtida para duas situações distintas: vigas de alma cheia e vigas
celulares. Uma avaliação crítica sobre a resposta dinâmica das passarelas possibilita
verificar a influência dos furos nas almas das vigas metálicas, mediante a obtenção
das acelerações de pico, focando aspectos associados ao conforto humano,
considerando-se comparações com normas e recomendações de projeto.Height limitations are frequent in multi-storey buildings due to zoning regulations, economic requirements and aesthetical considerations. Moreover, to provide for the passage of large diameter pipes in steel beams a high ceilings is usually required. The most adopted solution is the use of holes in the steel beams web in order to enable the passage of services. Therefore, the main objective of this research work is to evaluate the dynamic behaviour of footbridges, where structural design includes the use of cellular steel beams. The present study was carried out based on a load model developed to incorporate the dynamic effects induced by people walking. In this load model the transient effect due to the human heel impact was considered and the position of the dynamic load is changed according to individual position. The investigated structural model was based on a series of steelconcrete composite footbridges, with main spans varying from 10m to 30m. The proposed computational model, developed for the structural system dynamic analysis, adopted the usual mesh refinement techniques present in finite element method simulations, based on the Ansys program. The footbridges dynamic response was investigated considering two different design solutions: beams filled soul and cellular beams. The influence of the holes in the composite beams web over the footbridges dynamic response was investigated and the peak accelerations were obtained and compared with results supplied by design codes and recommendations aiming human comfort evaluations.
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Zúñga, José Eduardo Villarroel. "Análise da resposta dinâmica experimental de uma passarela tubular mista, aço-concreto, submetida ao caminhar humano." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=5531.
Full textAbstract:
Este trabalho de pesquisa apresenta como objetivo principal o desenvolvimento de investigação experimental dinâmica sobre estrutura real de uma passarela tubular mista aço-concreto. O sistema estrutural objeto deste trabalho corresponde a uma passarela composta por três vãos (32,5m, 17,5m e 20,0m, respectivamente) e dois balanços (7,50m e 5,0m, respectivamente), com comprimento total de 82,5m. A passarela com estrutura contínua de aço com as ligações soldadas se apoia em quatro pórticos também de aço. Estruturalmente está constituída por duas treliças planas que se interligam através de contraventamentos horizontais fixados na corda superior e inferior da treliça e lajes de concreto, formando um sistema misto com interação completa. A estrutura está submetida correntemente à travessia de pedestres e ciclistas. Testes experimentais foram realizados sobre o sistema estrutural e confrontados com resultados numéricos. Para a modelagem numérica do sistema são empregadas técnicas usuais de discretização, via método dos elementos finitos (MEF), por meio do programa ANSYS. Os resultados experimentais são analisados de acordo com a metodologia desenvolvida, sendo realizada análise modal experimental para a determinação das propriedades dinâmicas: freqüências, modos e taxa de amortecimento, enquanto que os resultados da estrutura, em termos de aceleração de pico, são comparados com os valores limites propostos por diversos autores, normas e recomendações de projeto, para uma avaliação do desempenho da estrutura em relação a vibração quando solicitada pelo caminhar dos pedestres no que diz respeito a critério para conforto humano.This research has as main objective the development of a dynamical experimental investigation of a real structure a tubular composite steel-concrete footbridge. The structural system of this study corresponds to a footbridge composed by three spans (32,5m, 17,5m and 20,0m, respectively) and two overhangs (7,50m and 5,0m, respectively), spanning 82,5m. The investigated structural model is composed by a continuous tubular steel structure with welded connections supported by four double file steel columns. It is structurally composed of two plane trusses are intertwined by horizontal bracing set in upper and lower chord of the truss and slabs of concrete, forming effective composite with complete interaction. This structure is currently submitted to pedestrians and cyclists crossing. Experimental tests were carried out on the structural system and with the numerical results. For the numerical modeling, discretization techniques via finite element method were applied, based on the ANSYS program. The experimental results were analyzed according to the developed methodology, and a modal analysis was implemented to determine the dynamical properties: frequencies, mode shapes and modal damping ratio, while the structure results in terms of peak acceleration, was obtained and compared to the limit values proposed by several authors and design recommendations, for the structure performance by pedestrian walking regarding the acceptance criteria for human comfort.
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Segundinho, Pedro Gutemberg de Alcântara. "Estudo das vibrações induzidas por pedestres em passarelas de madeira." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/18/18134/tde-14072010-090640/.
Full textAbstract:
No Brasil, o estudo a respeito das vibrações induzidas por pedestres em passarelas vem sendo realizado a partir do início dos anos 1990, para passarelas de concreto e de aço. No entanto, ainda não há registro de estudos desse tipo e a norma brasileira NBR 7190 (1997) de projeto de estruturas de madeira apresenta somente critérios de dimensionamento para carregamentos estáticos, no caso de passarelas de madeira. Nesse contexto, este trabalho tem como objetivo geral a análise teórica, numérica e experimental de passarelas de madeira simplesmente apoiadas, com vistas a propor recomendações de projeto relacionadas ao conforto humano nessas estruturas. Este estudo foi desenvolvido a partir da análise de diretrizes normativas e critérios sugeridos por diversos autores, da análise teórica de passarelas dimensionadas segundo os critérios da NBR 7190 (1997), de modelos numéricos construídos em elementos finitos e de ensaios experimentais em modelo reduzido. Entre as conclusões alcançadas, destaca-se que a formulação de Euler-Bernoulli é adequada para o cálculo da primeira frequência natural nas direções transversal vertical e transversal horizontal em passarelas de madeira simplesmente apoiadas; entretanto, especial atenção deve ser dada para a avaliação da rigidez à flexão na direção transversal horizontal. Finalmente, sugeriu-se uma proposta para verificação do estado limite de serviço devido às vibrações induzidas por pedestres em passarelas de madeira simplesmente apoiadas, no tocante ao cálculo de frequências e acelerações, a ser inserida na futura revisão da norma brasileira de projeto de estruturas de madeira.In Brazil, studies about pedestrian-induced vibrations on footbridges have been carried out since the early 1990s, for concrete and steel footbridges. However, there is no record of such studies and the brazilian standard NBR 7190 (1997) for the design of timber structures only presents design requirements for static loads, in the case of timber footbridges. Therefore, this paper aims to general theoretical analysis, numerical and experimental simply-supported beams timber footbridges, with a view to proposing recommendations for projects related to human comfort in these structures. This study was developed from the study of standards guidelines and criteria suggested by several authors, the theoretical analysis of footbridges design according to the criteria of the NBR 7190 (1997), numerical models using finite element and experimental tests on reduced model. Among the conclusions reached, it is emphasized that the formulation of Euler-Bernoulli is suitable for calculating the first natural frequency in vertical and lateral directions simply-supported beams timber footbridges; however, special attention should be given to the evaluation of lateral bending stiffness. Finally, we have suggested a proposal serviceability limit state verification due to pedestrian-induced vibrations on simply-supported beams timber footbridges, concerning the calculation of frequencies and accelerations to be included in a future review of the brazilian standard for the design of timber structures.
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Zäll, Emma. "Footbridge Dynamics : Human-Structure Interaction." Licentiate thesis, KTH, Bro- och stålbyggnad, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-224527.
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For aesthetic reasons and due to an increased demand for cost-effective and environmentally friendly civil engineering structures, there is a trend in designing light and slender structures. Consequently, many modern footbridges are susceptible to excessive vibrations caused by human-induced loads. To counteract this, today's design guidelines for footbridges generally require verification of the comfort criteria for footbridges with natural frequencies in the range of pedestrian step frequencies. To ensure that a certain acceleration limit is not exceeded, the guidelines provide simplified methodologies for vibration serviceability assessment. However, shortcomings of these methodologies have been identified. First, for certain footbridges, human-structure interaction (HSI) effects might have a significant impact on the dynamic response. One such effect is that the modal properties of the bridge change in the presence of a crowd; most importantly, the damping of the bridge is increased. If this effect is neglected, predicted acceleration levels might be overestimated. Second, as a running person induces a force of greater amplitude than a walking person, a single runner might cause a footbridge to vibrate excessively. Hence, the running load case is highly relevant. These two aspects have in common that they are disregarded in existing design guidelines. For the stated reasons, the demand for improvements of the guidelines is currently high and, prospectively, it might be necessary to require the consideration of both the HSI effect and running loads. Therefore, this licentiate thesis aims at deepening the understanding of these subjects, with the main focus being placed on the HSI effect and, more precisely, on how it can be accounted for in an efficient way. A numerical investigation of the HSI effect and its impact on the vertical acceleration response of a footbridge was performed. The results show that the HSI effect reduces the peak acceleration and that the greatest reduction is obtained for a crowd to bridge frequency ratio close to unity and a high crowd to bridge mass ratio. Furthermore, the performance of two simplified modelling approaches for consideration of the HSI effect was evaluated. Both simplified models can be easily implemented and proved the ability to predict the change in modal properties as well as the structural response of the bridge. Besides that, the computational cost was reduced, compared to more advanced models. Moreover, a case study comprising field tests and simulations was performed to investigate the effect of runners on footbridges. The acceleration limit given in the design guideline was exceeded for one single person running across the bridge while a group of seven people walking across the bridge did not cause exceedance of the limit. Hence, it was concluded that running loads require consideration in the design of a footbridge.På grund av estetiska skäl och en ökad efterfrågan på kostnadseffektiva och miljövänliga konstruktioner är merparten av de gångbroar som konstrueras idag förhållandevis lätta och slanka. Med anledning av detta ökar risken för att stora svängningar uppstår på grund av dynamisk belastning från människor på bron. För att motverka att detta inträffar kräver dagens normer att komforten verifieras för gångbroar med egenfrekvenser inom området för människans stegfrekvens. Komforten verifieras genom att säkerställa att ett visst accelerationskriterium inte överskrids. För detta ändamål finns handböcker som tillhandahåller förenklade beräkningsmetoder för uppskattning av accelerationsnivåer. Brister i dessa beräkningsmetoder har emellertid identifierats. För det första kan olika typer av människa-bro-interaktion (HSI) ha en betydande inverkan på responsen hos vissa broar. Exempel på en HSI-effekt är att brons modala egenskaper förändras när människor befinner sig på bron; i huvudsak sker en ökning av brons dämpning. Om denna effekt inte tas i beaktande föreligger stor risk att överskatta förväntade accelerationsnivåer. För det andra är kraften från en löpare större än kraften från en gående person vilket gör att en ensam löpare på en gångbro kan ge upphov till accelerationsnivåer som överskrider gränsvärdena för komfort. Löpande personer är därför ett mycket relevant lastfall. Befintliga normer uttrycker inte explicit att någon av dessa aspekter bör tas i beaktande. Behovet av förbättrade riktlinjer för hur normerna bör tillämpas är därför mycket stort och i framtiden kan det bli nödvändigt att kräva att både HSI-effekter och löparlaster tas i beaktande. Därför syftar denna licentiatavhandling till att bidra till en fördjupad förståelse inom dessa två ämnen, med huvudfokus på ovan nämnda HSI-effekt i allmänhet och hur den kan beaktas på ett enkelt, noggrant och tidseffektivt sätt i synnerhet. En numerisk undersökning av HSI-effekten och dess inverkan på den vertikala responsen hos en gångbro genomfördes. Resultaten visar att HSI-effekten reducerar den maximala accelerationen och att störst reduktion erhålls då folksamlingen och bron har ungefär samma egenfrekvens och då folksamlingens massa är stor i förhållande till brons massa. Vidare utvärderades två förenklade metoder för beaktande av HSI-effekten vilka kan implementeras av konstruktörer med grundläggande kunskaper inom strukturdynamik. Det konstaterades att båda metoderna uppskattar HSI-effekten såväl som brons respons förhållandevis väl samtidigt som de reducerar beräkningstiden något jämfört med mer avancerade metoder. Effekten av löpare på gångbroar studerades genom en fallstudie med fältmätningar. Utifrån resultaten från dessa fältmätningar kunde det konstateras att accelerationsgränsen som anges i normerna överskreds när en ensam löpare sprang över bron men inte när en grupp på sju personer gick i takt över samma bro. Därför drogs slutsatsen att löparlaster bör tas i beaktande vid dimensionering av en gångbro.
QC 20180320
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Rusňák, Marek. "Lávka pro pěší." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372113.
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The main goal of this diploma thesis is a design and verification of a steel footbridge crossing the river Dřevnice in Zlín. As the basic material steel S355 and for selected members steel S235 was chosen. There are two structural variants designed in the introductory part of the thesis. These variants are then compared and in the next part only selected, more favourable variant, is addressed. The selected variant is a truss footbridge with a bridge deck at the bottom and curved top chords. The bridge deck consists of floor beams and steel plate with longitudinal stiffeners. The span of the structure is 35.0 m, the width of the footbridge is 3.9 m and its height in the middle of the span is 4.2 m.
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Peña, Williams Dias Lozada. "Modelagem do caminhar humano e avaliação de conforto humano de passarelas de pedestres." Universidade do Estado do Rio de Janeiro, 2015. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=9073.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCom o passar dos anos a engenharia estrutural passou a lidar com a exigência cada vez maior de estruturas que ocupem menos espaço e sejam consideravelmente mais leves. No caso de passarelas de pedestres, a esbeltez da estrutura aliada a um baixo peso pode acarretar em problemas de vibrações devido à ressonância com o caminhar dos pedestres. Estes problemas podem variar desde uma simples sensação de desconforto até problemas mais graves como o colapso estrutural. Com base nestas premissas, esta dissertação visa investigar dois modelos estruturais, um em concreto armado e outro misto, do tipo aço concreto, onde os modelos serão estudados mediante o emprego do método dos elementos finitos através do programa ANSYS. Os modelos numéricos permitem determinar as frequências naturais da estrutura e consequentemente estudar as respostas dos modelos mediante análises de vibrações forçadas. As respostas dinâmicas da estrutura serão obtidas em termos dos valores dos deslocamentos máximos e das acelerações de pico. Os resultados obtidos foram comparados com os principais guias que regem o conforto humano no caso de caminhar de pessoas em passarelas de pedestres, de forma que houve indicativos de possíveis desconfortos após a análise dos resultados obtidos ao longo da investigação. Finalmente, foi feito um estudo considerando-se movimentos aleatórios dos pedestres sobre as passarelas, objetivando estudar os níveis da resposta dinâmica das estruturas nestas situações.
The structural engineer needs to adapt with the exigencies of low weight and less space occupied by the structures, which have been increasing more and more over the years. Related to footbridges, the structure slenderness and the low weight may lead to vibrations problems due to resonance with pedestrians walking. These problems may vary from a simple discomfort up to big problems, like the structural collapse. According to these premises, this dissertation aims to investigate two structural models, the first one in reinforced concrete and the other is related to a steel-concrete composite pedestrian footbridge, which will be analyzed by finite element method simulations using the software ANSYS. The numerical models make possible to evaluate the natural frequencies of structures and study the response due to forced vibrations induced by pedestrians walking. The dynamic responses of the investigated footbridges will be analyzed considering the maximum displacements and accelerations. The obtained results were compared with the main guidelines related to human comfort with regard to pedestrian walking on footbridges, in such a way that it showed possible problems due to vibrations, after analyzing the results obtained in the investigation. Thus, it was performed a study considering the variance of pedestrian position in order to analyze the dynamic response of the investigated footbridges in these cases.
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Mendes, Joesley Pereira. "Análise dinâmica e controle de vibrações de passarelas de pedestres submetidas ao caminhar humano." Universidade do Estado do Rio de Janeiro, 2014. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=7465.
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Fundação de Amparo à Pesquisa do Estado do Rio de JaneiroPassarelas de pedestres mistas (aço-concreto) e de aço são frequentemente submetidas a ações dinâmicas de magnitude variável, devido à travessia de pedestres sobre a laje de concreto. Estas ações dinâmicas podem produzir vibrações excessivas e dependendo de sua magnitude e intensidade, estes efeitos adversos podem comprometer a confiabilidade e a resposta do sistema estrutural e, também, podem levar a uma redução da expectativa de vida útil da passarela. Por outro lado, a experiência e o conhecimento dos engenheiros estruturais em conjunto com o uso de novos materiais e tecnologias construtivas têm produzido projetos de passarelas mistas (aço-concreto) bastante arrojados. Uma consequência direta desta tendência de projeto é um aumento considerável das vibrações estruturais. Com base neste cenário, esta dissertação visa investigar o comportamento dinâmico de três passarelas de pedestres mistas (aço-concreto) localizadas no Rio de Janeiro, submetidas ao caminhar humano. Estes sistemas estruturais são constituídos por uma estrutura principal de aço e laje em concreto e são destinados à travessia de pedestres. Deste modo, foram desenvolvidos modelos numérico-computacionais, adotando-se as técnicas tradicionais de refinamento presentes em simulações do método de elementos finitos, com base no uso do software ANSYS. Estes modelos numéricos permitiram uma completa avaliação dinâmica das passarelas investigadas, especialmente em termos de conforto humano. As respostas dinâmicas foram obtidas em termos de acelerações de pico e comparadas com valores limites propostas por diversos autores e normas de projeto. Os valores de aceleração de pico e aceleração rms encontrados na presente investigação indicaram que as passarelas analisadas apresentaram problemas relacionados com o conforto humano. Assim sendo, considerando-se que foi detectado que estas estruturas poderiam atingir níveis elevados de vibração que possam vir a comprometer o conforto dos usuários, foi verificado que uma estratégia para o controle estrutural era necessária, a fim de reduzir as vibrações excessivas nas passarelas. Finalmente, uma investigação foi realizada com base em alternativas de controle estrutural objetivando atenuar vibrações excessivas, a partir do emprego de sistemas de atenuadores dinâmicos sintonizados (ADS).
Steel and steel-concrete composite pedestrian footbridges are frequently subjected to dynamic actions with variable magnitudes due to the pedestrian crossing on the concrete deck. These dynamic actions can produce excessive vibrations and depending on their magnitude and intensity, these adverse effects can compromise the structural systems response and its reliability and may also lead to a reduction of the expected footbridge service life. The structural engineers experience and knowledge together with the use of newly developed materials and technologies have produced steel-concrete composite daring footbridges. A direct consequence of this design trend is a considerable increase of structural vibrations. Based on this scenario, this dissertation aims to investigate the dynamic behaviour of three steel-concrete composite pedestrian footbridge submitted to human walking vibration, located at Rio de Janeiro. These structural systems are composed by steel structure and a concrete slab and are destined for pedestrian crossing. Computational models were developed adopting the usual mesh refinement techniques present in finite element method simulations using ANSYS software. These numerical models have enabled a complete dynamic evaluation of the investigated footbridges especially in terms of human comfort and its associated vibration serviceability limit states. The dynamic responses were obtained in terms of peak accelerations and were compared to the limiting values proposed by authors and design standards. The peak acceleration values found in the present investigation indicated that the analysed footbridges have presented problems related to human comfort. Considering that it was detected that these structures could reach high vibration levels that might compromise the footbridge users comfort, it was proposed a structural control system in order to reduce the excessive vibrations. Thus, an investigation was performed based on some structural control alternatives for attenuating excessive vibrations using tuned mass damper (TMD) systems.
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Mabe, Malesiba Millicent. "A Location - Allocation Model For Pedestrian Footbridge infrastructure: A Case Study on the South Africa's National Roads Agency Limited (SANRAL) Network in Gauteng." Master's thesis, Faculty of Engineering and the Built Environment, 2021. http://hdl.handle.net/11427/32764.
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Road fatalities are one of the leading causes of unnatural deaths in developing countries, such as South Africa. According to the Road Traffic Management Corporation (2017), the number of road traffic fatalities were recorded to be 11 676 in the year 2016 and 42.6% of these road traffic fatalities involved pedestrian. According to the National Road Safety Strategy 2016 – 2030 most pedestrian crashes are due to illegal pedestrian crossings mainly across high speed roads (highways) (Department of Transport, 2011). The research study aims to develop a geo-spatial model to determine the most suitable location to allocate pedestrian footbridge infrastructure along the South African National Road Agency Limited (SANRAL) network in Gauteng Province. Previously road planning and design in South Africa followed international best practices, with development of the highway road system mainly orientated to serve motorised transport by primarily providing infrastructure for vehicular traffic along the highways , as pedestrians and highways were not expected to coexist in any proximity to each other. The presence of pedestrians along highways can no longer be ignored and there is a great need to overcome the highly fragmented spatial planning formed by the apartheid policies. For most non-motorised transport (NMT) users in South Africa, highways offer the shortest and most efficient direct routes, but also represent a major obstacle for many pedestrians who are separated by them. Limited studies on the location and allocation of the pedestrian footbridge for pedestrians are reported in the literature, further research in this field should be considered, especially along the SANRAL network where there are high number of residential areas along high-speed roads, this behaviour is unique and common in South Africa. Based on a literature review the factors affecting the location and allocation of pedestrian footbridges were identified, the following were factors identified: population density (serviced by the pedestrian footbridge), land use activities, socio-economic characteristics of the population (e.g. Gender, employment, race, and income level), crash hotspots/statistics (along the route), distance to access bridge and vehicle traffic volume along the route. From these factors spatial data was gathered to carry out spatial multi-criteria analyses (SMCA). The results from the spatial analysis showed that high population densities adjacent to highway, accessibility and land use are key in the location of pedestrian footbridge. The results also show that there is a strong correlation between: land use diversity, socio-economic, crash hotspots/statistics (along the route), vehicle traffic volume and population density (serviced by the pedestrian footbridge). The higher an area has these factors, the Higher the Pedestrian Footbridge location index (high pedestrian footbridge location demand), hence the recommendation to allocate in those locations.
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Mangione, Anthony F. "Reconciling Craft with Digital Design: Building a New Infrastructure." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1448037156.
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Báča, Pavel. "Lávka pro pěší." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225482.
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The subject of this student work is the design of a load-bearing steel structure of a footbridge for pedestrians. The footbridge connects two buildings in the locality of Brno - Bohunice. It includes the bridging of a road, car park and entrances of the both buildings. The construction of the footbridge is solved in three variants with the best variant selected.
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Thufvesson, Eric, and Daniel Andersson. "Dynamic Analysis of the Skyway Bridge : Assessment and Application of Design Guidelines." Thesis, KTH, Bro- och stålbyggnad, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-208685.
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In recent years the design of pedestrian bridges has become more slender. As a result the bridges has lower natural frequencies and are more prone to excessive vibrations when subjected to dynamic loads induced by pedestrians. Akademiska Hus are building such a bridge at Nya Karolinska Solna where the bridge will span over Solnavägenconnecting the hospital building, U2, and the research facility BioMedicum. Due to practical reasons, it is not possible to connect one of the bridge ends mechanicallyto the building which increases the risk for lateral modes in the sensitivefrequency range of 0-2.5 Hz. The increased risk of lateral modes of vibrations within the sensitive frequency range as well uncertainties when determining the dynamic response led to this thesis. This thesis covers a frequency analysis of the previously mention bridge and an evaluation of the dynamic response under pedestrian loading by implementation of several design guidelines. A literature review was conducted with the aim of giving a deeper knowledge of human induced vibrations and the relevant guidelines for modelling of pedestrian loading. Furthermore, a parametric study was conducted for parameters which might be prone to uncertainties in data. The investigated parameters were the Young’s modulus for concrete and the surrounding fill materialas well as the stiffness of the connection to BioMedicum. The parametric study yielded a frequency range of 2.20-2.93 Hz for the first lateral mode and 5.96-6.67 Hz for the first vertical mode of vibration. By including nonstructural mass the lower limit for the frequencies were lowered to 2.05 and 5.59 Hzin the first lateral and vertical mode respectively. The parametric study also showed that the largest impact on the natural frequencies were obtained by manipulating the parameters for the supports, both for BioMedicum and the substructure. The implementation of the guidelines resulted in a lateral acceleration between 0.05 and0.599 m/s2. No evaluation was conducted for the dynamic response in the vertical direction due to a natural frequency of 5.59 Hz, which is higher than the evaluation criteria stated in Eurocode 0. The results showed that the design of the Skyway bridge is dynamically sound with regard to pedestrian loading and no remedial actions are necessary.
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Maleňák, Jan. "Lávka pro pěší v Kyjově." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265316.
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The content of diploma thesis is design of the construction of steel footbridge for pedestrians and cyclists. The footbridge is across the railway in Kyjov. The design will be processed in two options of structure. The selected option will be developed in greater detail. The span of footbridge is 35 m and the width is 3 m. The contruction is made by two arched beams which are connected to the bridge deck by suspenders. The stability of the construction is provided by longitudinal bracing under the bridge deck and the bracing between the arched beams. The assessment of the structure was made according to valid standards.
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Tačner, Jan. "Analýza působení větru na stavební konstrukci." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227314.
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Diploma thesis deals with static and dynamic analyses of a slender bridge structure behavior. The footbridge structure model was created in ANSYS 14.5 programing system. Static and a modal analyses were made afterwards and according to these analyses dynamic wind load and dynamic pedestrian load were applied. Wind load was applied as option of deck without a handrail and as option of deck with fully airtight handrail. Pedestrians were perceived as group of pedestrians and as a sparse crowd. Both applied loads were solved by harmonic analyses. Results of these analyses are resonance curves and tables of accleration.
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Pham, Hoang Anh. "Lávka pro pěší přes řeku Dyji v Břeclavi." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392109.
Full textAbstract:
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.
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Libiger, Martin. "Lávka pro pěší přes řeku Labe." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227573.
Full textAbstract:
The thesis deals with a design of the river Labe bridging in the city Hradec Kralove. In order to make option for cyclists and pedistrians to cross between shores. There were made three design variants. For detailed solution curved twin-arm arched structure was chosen. The aim of the thesis was design and assessment of Bering strucutre of the footbridge according ultimate limit states and serviceability limit state given by valid Eurocodes.
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Bartoň, Radek. "Ocelová lávka pro pěší." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227509.
Full textAbstract:
This diploma thesis contains a study of current composite structure of footbridge and in part II design and assessment of steel structure of footbridge for pedestrians and cyclists placed on current footbridge location. Current footbridge is located on "nábřeží Dukelských hrdinů" in Rožnov pod Radhoštěm. In part I, assessment of the current composite structure of footbridge is done, using ČSN and ČSN EN standards for adjusted static behavior of the structure. Comparison of both assessments is made and also with an original assessment from 1988. In part II, design and assessment of steel structure of footbridge placed on currents footbridge location described in part I is done.The structure was designed as two vierendeels trusses connected with cross beams, supporting concrete bridge deck. 9 variants were examined, differing with truss height and the number of verticals. Detailed design and assessment for parts of the structure is done for the chosen variant.
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Hibš, Daniel. "Lávka pro pěší." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392084.
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This diploma thesis deals with the design of a new bridge construction over a multi-lane communication. The converted road is a pedestrian and biking trail connecting significant agglomerations. Three studies were worked out in this thesis and the C variant was selected for further detailed processing. It is an unsymmetrical suspended bridge with a cast-in-place deck. In the section above the communication, the bridge is made up of prefabricated segments. Suspension of the structure is made of two sloping pylons forming a V-shape. The analysis of the construction was carried out in the MIDAS Civil program, where a complete model of construction was entered, including a subsequent estacade. The model describes the construction process and includes creep and shrinkage of the concrete. The traffic, temperature and wind loads were used. The design was assessed for the ultimate limit states and serviceability limit states. The assessment was carried out in the IDEA StatiCa program, supplemented by manual calculations. The static calculations also include assessment of the harmonic response. Subsequently, overview drawings, detailed drawings and visualizations were developed.
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Blaška, Jan. "Lávka pro pěší." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265483.
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The subject of the final thesis is timber footbridge for pedestrians and cyclists over the Desna river in Loucna nad Desnou village. The length of the footbridge is 30 m, width 3 m and height is variable from 4 to 5 m. The footbridge is covered with roof inclination of 20° in transverse direction and the roof is arch in longitudinal direction. Roofing is metal sheet. The structure is three-dimensional truss consists of two truss connected by rafters, floor beams and by members of bracing. The 2D-truss consists of bottom chord, top arch chord and webs. There are end posts made of streel bracing frames. The material of structure is mostly glued laminated timber, then timber and steel. The steel is used for connectors and steel bracing frames.
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Řehová, Jana. "Analýza dynamického chování štíhlé mostní konstrukce a návrh zařízení na omezení vibrací." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409744.
Full textAbstract:
This master thesis deals with the dynamic analysis of a footbridge. Computational model of the footbridge was created using ANSYS software. The model was subjected to dynamic wind load in longitudal and lateral direction. Furthermore pedestrian load in lateral direction was analyzed. Afterwards, due to unsatisfactory response to the pedestrian laod, a tuned mass damper was introduced to reduce the vibration. This lead to decrease in the vibration to a satisfactory levels, as is shown in the analyses of the model.
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Janírek, Karel. "Zastřešená lávka pro pěší." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227824.
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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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"Footbride [i.e. Footbridge] re-configuration." 2009. http://library.cuhk.edu.hk/record=b5893934.
Full text
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"An introspective journey: bridge-reconstitution." 2007. http://library.cuhk.edu.hk/record=b5893167.
Full textAbstract:
Fong Man Sze, Anny."Architecture Department, Chinese University of Hong Kong, Master of Architecture Programme 2006-2007, design report."
STAGE I
what is introspection? --- p.page 1-18
why introspection? --- p.page 19-21
site interpretation --- p.page 22- 30
how to introduce introspection in architectural design? --- p.page 31-34
other studies --- p.page 35-43
STAGE II
design exploration --- p.page 44- 53
design development --- p.page 54- 67
final presentation --- p.page 68- 78
acknowledgement --- p.page 79
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"Living link." 2000. http://library.cuhk.edu.hk/record=b5890581.
Full textAbstract:
Chan Kum Lun Pillow."Architecture Department, Chinese University of Hong Kong, Master of Architecture Programme 1999-2000, design report."
Includes bibliographical references (leaf 51).
Acknowledgments --- p.1
Abstracts --- p.2
Chapter ONE --- Issue and Responses
Chapter - --- issue of walking --- p.3
Chapter - --- situation in Hong Kong --- p.5
Chapter - --- response and goals --- p.7
Chapter TWO --- Background and Research
Chapter - --- research process --- p.9
Chapter - --- Mongkok as selected district --- p.9
Chapter - --- analysis of Mongkok --- p.10
Chapter - --- opportunities in Mongkok --- p.16
Chapter THREE --- Concept and Program
Chapter - --- concept --- p.19
Chapter - --- site selection --- p.23
Chapter - --- program characteristics --- p.27
Chapter FOUR --- The Project Program
Chapter - --- the sites --- p.29
Chapter - --- definition of route --- p.31
Chapter - --- space program --- p.33
Chapter FIVE --- The Design
Chapter - --- concept development --- p.34
Chapter - --- layout development --- p.38
Chapter - --- the final design --- p.41
Chapter - --- elevations --- p.44
Chapter - --- sections --- p.45
Chapter SIX --- Special Study - structure and construction --- p.46
Bibliography --- p.51
Appendices
Chapter - --- site photos --- p.52
Chapter - --- schedule of accomodations --- p.53
Chapter - --- plans --- p.54
Chapter - --- design development --- p.57
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"A new typology of connection: structure vs architecture." 2007. http://library.cuhk.edu.hk/record=b5893163.
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"Walking experience on the wet land." 2011. http://library.cuhk.edu.hk/record=b5894556.
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Jhang, Jing, and 章. 靖. "Effect of Vibration Reduction of Suspension Typed Tuned Mass Damper with Double Pendulum Lengths and Analysis of Footbridges on Pedestrian Induced Vibration." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/txw9af.
Full textAbstract:
碩士國立臺灣大學
土木工程學研究所
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A simple pendulum consists of a mass which hangs from a string and fixes at a pivot point. By applying Newton''s secont law, the equation of motion for the pendulum could be obtained. In this study, the nonlinear and linear equation of motion of a pendulum and pendulum-structure system subjected to external forces is derived. The time history analysis is simulated using state-space method. The amplitude of angular displacement is small so that the equation of motion could be reduced as a simple harmonic equation of motion. This assumption is confirmed by comparing the time history analysis, frequency sensitivity analysis, and design parameter sensitivity analysis results. Passive tuned-mass dampers (TMDs) are a very efficient solution for the control of structural vibrations subjected to long-duration, narrowband excitations. In this study, a suspension typed tuned mass damper with double pendulum lengths is proposed. The pendular mass is suspensed by cables and linked with viscous dampers. The main advantage of the proposed double pendulum lengths TMD is that, it allows control of structural vibrations in both principal directions with different natural frequencies. Numerical results show that, under various wind force excitations, the level of response reduction achieved by the proposed double pendulum lengths TMD is much better than a single pendulum lengths TMD in both directions. Vibration behavior of the footbridge due to pedestrian loading has arised the attraction in these years. The cases of London Millennium bridge, Toda Park bridge in Japan, etc… show that the dynamic action of pedestrian loading should be taken into consideration in design procedures. According to those European footbridge design codes and some relative researches, the method of modeling pedestrian loadings acting on the footbridge is accomplished. Analysis and design procedures of a practical footbridge vibration reduction by TMD is performed in this study. These evaluation methods of footbridge vibration reduction are proposed for engineering applications.
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Teed, Jacqueline Mary. "Burning bridge : connection through interactivity, a design proposal for the Granville Bridge." Thesis, 2004. http://hdl.handle.net/2429/15858.
Full textAbstract:
The Granville Bridge, Vancouver, Canada is an unsafe, uncomfortable and uninteresting
crossing for pedestrians. Neither does it possess an identifiable or memorable image.
Although the City of Vancouver has identified poor crossing conditions for pedestrians as
an issue that requires addressing, the current design for the City's preferred solution - a
suspended crossing attached to the side of the Granville Bridge - the current design for
this structure does not address how to make the bridge an imageable element in the city
landscape. Using the Black Rock Arts Festival - commonly know as Burning Man - as a
case study, the potential for an interactive landscape design to create an identity for the
Granville Bridge is examined. Although Burning Man fails to create a community that
integrates with its contextual landscape, its use of interactive art is successful in creating
community among participants. Through the contextual use of interactive art in
conjunction with the proposed suspended pedestrian crossing, a design is proposed that
celebrates the Granville Bridge as a conduit of motion by revealing the presence of
pedestrians. The proposed design includes design components under the north and
south ends of the bridge to conceptually ground the image on the north and south side of
False Creek, and unifies the total design with the metaphorical and literal use of dance.
The design shows that interactive art can be used to make the Granville Bridge an
imageable element in the landscape, thereby making it an integral part of the Vancouver
landscape.Applied Science, Faculty of
Architecture and Landscape Architecture (SALA), School of
Graduate