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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Soil-Structure Interaction Analysis of Portal Frame Railway Bridges : Numerical Analysis of Two Case Study Bridges

Sandqvist, Nils, Milicevic, Marko January 2020 (has links)
This thesis concerns dynamic Soil-Structure Interaction (SSI) analysis of portal framerailway bridges. Dynamic problems are common for bridges used for high speedrailway traffic. The passing trains induce harmonic loads on the bridges causingvibration amplitudes that may cause damage to the bridge structures and userdiscomfort.Previous studies have shown that the effects of SSI are substantial for short spanportal frame bridges. The damping ratio of the system is greatly increased due to theenergy dissipation properties of the surrounding soil causing significant changes in thedynamic response of the structure. Therefore, it is of interest to investigate the effectsof SSI for portal frame bridges with longer spans.Two case study bridges with span lengths of approximately 16m have been investigatedin detail in this study. Dynamic analyses of the bridges and train passage simulationshave been performed. The results show that SSI significantly increases the dampingratio which leads to lower vibration amplitudes. It is also possible to draw theconclusion that more accurate results are achieved when modeling fixed foundationsrather than using static spring foundations to replicate the stiffness of the subsoil.Moreover, a simplified modeling approach accounting for the effects of SSI is proposed.The proposed method provides satisfactory results, but more future work may increasethe quality of the results further. To validate the conclusions from this study, a proposalfor experimental validation is presented. Performing full-scale dynamic tests on thestudied bridges would enable further comparison and validation of the results.
22

Sambandsanalys av sociala konsekvenser vid utbyggnad av transportsystem : En granskning av statistisk modellering för nyttobedömning av höghastighetsjärnväg / Analysis of relationships between investments in transport infrastructure and social consequences

Johansson, Gabriel, Engholm, Albin January 2016 (has links)
Sverige planerar för en av de största infrastrukturinvesteringarna någonsin i Sveriges historia. I fokus står en ny höghastighetsjärnväg mellan Stockholm, Göteborg och Malmö som ska möjliggöra resor på två till två och en halv timme mellan städerna. Runt denna investering finns en ambition att samla andra samhällsbyggande åtgärder, som ökat bostadsbyggande och förbättringar i lokal och regional kollektivtrafik, för att genom en samordnad planering få ut så stora nyttor som möjligt. För detta ändamål har regeringen tillsatt den statliga utredningen Sverigeförhandlingen. En viktig del av deras arbete är att få fram en finansieringslösning för den nya statliga transportinfrastrukturen där medfinansiering från kommuner, regioner och andra aktörer står för en betydande andel. Idén kring medfinansiering är baserad på att aktörerna ska bidra till finansieringen som motsvarar de nyttor transportinfrastrukturen bidrar till. Alltså måste det gå att uppskatta att på förhand hur mycket nyttor som uppstår och vad de är värda. Sverigeförhandlingen har valt klassificera nyttorna i sex kategorier där ”social nyttor” är en av dessa. Däremot finns ingen etablerad metodik för att uppskatta dessa. Det här examensarbetet undersöker vilken social påverkan transportinfrastrukturen ger upphov till. Detta görs genom att studera samband mellan tillgänglighet, alltså hur transportinfrastrukturen ger möjlighet för människor att nå olika målpunkter, och ett antal sociala förhållanden. Tillgänglighetsmåttet valdes utifrån studier av tidigare forskning samt etablerade modeller för uppskattning av andra nyttor av transportinfrastruktur. För att veta vilka sociala förhållanden som är intressanta att undersöka har en studie av Svensk och internationell litteratur på området genomförts. Sambandsanalysen bygger på statistiska metoder där data för Sveriges kommuner används. Metoden ger möjlighet till att identifiera samvariation mellan tillgänglighet och sociala förhållanden men är inte tillräcklig för att säkerställa att tillgänglighet är en orsak till de sociala förhållandena. Resultaten tyder på att tillgänglighet har statistiskt signifikanta samband med ett antal indikatorer för sociala förhållanden. Exempel på två av dessa är ungdomsidrottande och andelen barn som går i förskola. Det visade sig att de flesta av de sociala förhållanden som har signifikanta samband med tillgänglighet har en samvariation som tyder på att tillgänglighet korrelerar med positiva sociala förhållanden. Detta tyder på att tillgänglighet kan ha samband med faktorer som kan tolkas som sociala nyttor. Dock kan inget sägas om tillgänglighet är en orsak till detta eller om det är någon icke studerad orsak som ger upphov till detta. Dessutom påverkas tillgänglighetsmåttet av andra faktorer än enbart tillgång till transportinfrastruktur och därför går det inte utifrån dessa samband att säkert säga att de beror på transportsystemet. För att sociala nyttor ska kunna kvantifieras och ligga till grund för medfinansiering krävs vidare studier. En viktig uppgift är att med hjälp av bättre data och mer avancerade metoder få fram bättre uppskattningar av sambanden samt orsaksrelationerna. Det krävs också studier för hur sociala nyttor ska värderas i monetära termer ur ett samhällsekonomiskt perspektiv. / Sweden is currently planning for one of its largest investments in transport infrastructure ever. A cornerstone in the project is a new high speed railroad between Stockholm, Gothenburg and Malmö. A considerable portion of the funding will consist of co-funding from municipalities, regions and private actors that will benefit from the infrastructure. The amount of co-funding is based on the total benefits that each actor will receive. Therefore these benefits must be able to be quantified. This report aims to study relationships between transport infrastructure and a number of social consequences that previous research has indicated being interesting. The method used is based on econometric methods that enable identification of statistical relationships using a simple linear model. This requires measures of transport infrastructure and indicators for social well-being which are chosen through a study of literature and established models quantifying wider economic benefits from transport infrastructure.The report suggests that a gravitybased accessibility measure is suitable for quantifying transport infrastructure in this context. The results from the econometrical model ssuggest that there are several significant relationships between accessibility and social well-being. In general accessibility seems to correlate with positive social consequences. However it is likely that endogeneity is biasing the results and make it difficult to draw any conclusions on causal relationships. It is stated that further research studying these relationships more carefully with better adapted data for the purpose is required to be able to obtain quantified estimates that can be used in co-funding of transport infrastructure.
23

Parâmetros do projeto geométrico para trens de passageiros de alta velocidade e longo percurso. / Geometric design parameters of passenger trains for high speed and long journey.

Stech, Pedro Henrique 13 December 2011 (has links)
Este trabalho tem como objetivo principal direcionar a tomada de decisões para a escolha dos diferentes parâmetros que envolvem o alinhamento horizontal e vertical do projeto geométrico ferroviário de trens de alta velocidade (TAV) e de longo percurso, bem como descrever conceitos teóricos para parâmetros de segurança e conforto, baseados em normas internacionais. A pesquisa se desenvolve através de consultas em revistas especializadas, artigos, publicações, normas técnicas e livros. Pela escassez de dados em língua nacional e material bibliográfico desatualizado, as pesquisas se concentram essencialmente em material internacional. Apesar do Brasil ser um dos países em desenvolvimento com maior ascensão no cenário global, tem apresentado, nas últimas décadas, sérios problemas de infra-estrutura devido a uma distribuição desequilibrada na área de transportes, com altíssima concentração no modo rodoviário, com aeroportos e rodovias operando acima da capacidade satisfatória, além de um leque limitado de alternativas de transporte. Devido à falta de investimentos no setor ferroviário, grande parte da malha ferroviária brasileira tornou-se inoperante ou até mesmo inexistente, resultando numa enorme diminuição da mão de obra qualificada e formação acadêmica nesse ramo. Como conseqüência, os estudos relacionados ao projeto ferroviário também foram afetados diretamente. Nesse contexto, é importante que se resgate normas, publicações, especificações técnicas e experiências adotadas em outros países com sólidas tradições ferroviárias, de modo a incorporar em nossa formação acadêmica tais conceitos, como é um dos objetivos dessa dissertação. / This dissertation has as main objective to guide in taking decisions for the selection of different parameters which involve the horizontal and vertical railway geometric design of high speed (HST) and long distance trains as well as theoretical concepts for describing security parameters and comfort, based on international standards. The research is developed through consultations in specialized magazines, articles, publications, standards and technical books. Due to the scarcity of data in the national language and outdated library materials, the research focuses primarily on international material. Although Brazil is a developing country with one of the highest rises in the global scene, the country has faced in recent decades serious infrastructure problems due to an uneven distribution in the area of transport, with high concentration in the road, and airports and roads operating above satisfactory capacity, resulted by a limited range of transportation alternatives. Due to the lack of investment in the railway sector, much of the Brazilian railway system became inoperative or even nonexistent, resulting in a tremendous decrease of skilled labor and academic training in this field. As a result, studies related to the railway project have also been directly impacted. In this context, it is important to rescue standards, publications, experiences and technical specifications adopted in other countries with strong tradition in railways in order to incorporate these concepts into our academic formation, which is one of the purposes of this dissertation.
24

Du TGV Rhin-Rhône au "Territoire" Rhin-Rhône : réticularité, mobilité et territorialité dans un espace intermédiaire / From the Rhin-Rhône TGV to the Rhin-Rhône "territory" : reticularity, mobility and territoriality in an intermediary space

Carrouet, Guillaume 19 March 2013 (has links)
La grande vitesse ferroviaire, destinée à réduire les distances-temps entre les grandes métropoles françaises et européennes, conduit à inscrire les espaces intermédiaires dans une situation peu favorable. Fortement polarisé par les grands foyers urbains qui l’encadrent, ce type d’espace est généralement réduit à son unique statut d’aire de transit. Pourtant, la branche Est, premier tronçon du projet de LGV Rhin-Rhône, de par sa dimension régionale, constitue le facteur d’émergence d’un processus de territorialisation de l’aire Rhin-Rhône. Ainsi, l’arrivée de la grande vitesse ferroviaire est à l’origine de la création d’un réseau de villes qui s’étend de Dijon à Bâle. Pour répondre à cette problématique territoriale, l’analyse fine des configurations spatiales, enrichie par l’approche des représentations, permet de voir dans quelle mesure l’aire Rhin-Rhône est, à l’heure actuelle, dépourvue d’une dimension territoriale. Ensuite, l’entrée par les configurations des réseaux de transport et les pratiques de mobilité permettent de voir comment le projet de LGV Rhin-Rhône s’insère au sein de l’aire d’étude. Enfin, les trois formes d’appropriation choisies : les jeux d’acteurs dans la définition du tracé, les projets de valorisation et les stratégies de promotion territoriale associées à la nouvelle offre ferroviaire, visent à montrer comment les perceptions des gains d’accessibilité par les acteurs locaux peuvent conduire à inscrire l’aire Rhin-Rhône dans un processus de territorialisation. Cette recherche met en évidence la difficile adaptation de la grande vitesse ferroviaire à la desserte des espaces intermédiaires. La localisation des nouvelles gares TGV en périphérie des agglomérations franc-comtoises et la construction de deux contournements ferroviaires aux extrémités de la LGV, constituent des freins au développement de la grande vitesse régionale, condition pourtant nécessaire au fonctionnement territorial de l’aire Rhin-Rhône. En plus d’être un facteur du renforcement de la situation intermédiaire de l’aire Rhin-Rhône, la branche Est exacerbe les concurrences et rivalités entre territoires. En témoigne la redondance des projets de valorisation destinés à accueillir des activités tertiaires, les agglomérations, séparées seulement d’une centaine de kilomètres, adoptant des stratégies similaires. Si l’analyse de l’insertion de la branche Est au sein de l’aire Rhin-Rhône souligne la rigidité du modèle français à grande vitesse, ce cas d’étude fournit des pistes de réflexion sur l’élaboration des futurs projets de LGV, dont la réalisation sera étroitement dépendante du soutien financier des collectivités territoriales. / High-speed rail, destined to reduce the times-distances between major French and European cities, tends to push intermediary spaces into a rather unfavorable situation. Strongly polarized by the large urban centers that surround them, these intermediary areas are usually reduced to their sole status of transit areas. However, the Eastern tract, the first section of the LGV Rhine-Rhône project, through its regional dimension, constitutes a factor in the emergence of a territorialization process of the Rhine-Rhone area. Thus, the arrival of high speed rail is responsible for the creation of a network of cities that extends from Dijon to Basel.To address this territorial issue, a detailed analysis of spatial patterns, enriched by a representative approach, allows one to realize how devoid of any territorial dimension the Rhine-Rhône area currently is. A subsequent focus on the configurations of the transportation networks and on human-mobility practices shows how the proposed Rhine-Rhône LGV fits into the study area. Finally, the three forms of appropriation strategies selected; the stakeholders’ interactions in the project delineation, the development projects and the territorial promotion strategies associated to the new rail service, are aimed at showing how perceptions of accessibility gains by local stakeholders can lead to the inclusion of the Rhine-Rhone area into a process of territorialization.This research highlights the difficult adaptation of high-speed rail to the service of intermediary spaces. The location of new TGV stations on the outskirts of Franche-Comté cities and the construction of two railway bypasses at the ends of the LGV, constitute hurdles to the development of a regional high speed network, itself a necessary pre-condition to a territorial operation of the Rhine-Rhône area. In addition to being a factor in the cementing of the intermediary situation of the Rhine-Rhône area, the Eastern tract exacerbates territorial competition and rivalry. This is further shown by the redundancy of development projects designed to accommodate tertiary activities, whereby cities, separated by a mere hundred kilometers, adopt similar strategies. While the analysis of the insertion of the Eastern tract into the Rhine-Rhone area emphasizes the rigidity of the French high-speed model, this case study provides food for thought on the development of future LGV projects, whose implementation will be closely dependent upon the financial support of local authorities.
25

Parâmetros do projeto geométrico para trens de passageiros de alta velocidade e longo percurso. / Geometric design parameters of passenger trains for high speed and long journey.

Pedro Henrique Stech 13 December 2011 (has links)
Este trabalho tem como objetivo principal direcionar a tomada de decisões para a escolha dos diferentes parâmetros que envolvem o alinhamento horizontal e vertical do projeto geométrico ferroviário de trens de alta velocidade (TAV) e de longo percurso, bem como descrever conceitos teóricos para parâmetros de segurança e conforto, baseados em normas internacionais. A pesquisa se desenvolve através de consultas em revistas especializadas, artigos, publicações, normas técnicas e livros. Pela escassez de dados em língua nacional e material bibliográfico desatualizado, as pesquisas se concentram essencialmente em material internacional. Apesar do Brasil ser um dos países em desenvolvimento com maior ascensão no cenário global, tem apresentado, nas últimas décadas, sérios problemas de infra-estrutura devido a uma distribuição desequilibrada na área de transportes, com altíssima concentração no modo rodoviário, com aeroportos e rodovias operando acima da capacidade satisfatória, além de um leque limitado de alternativas de transporte. Devido à falta de investimentos no setor ferroviário, grande parte da malha ferroviária brasileira tornou-se inoperante ou até mesmo inexistente, resultando numa enorme diminuição da mão de obra qualificada e formação acadêmica nesse ramo. Como conseqüência, os estudos relacionados ao projeto ferroviário também foram afetados diretamente. Nesse contexto, é importante que se resgate normas, publicações, especificações técnicas e experiências adotadas em outros países com sólidas tradições ferroviárias, de modo a incorporar em nossa formação acadêmica tais conceitos, como é um dos objetivos dessa dissertação. / This dissertation has as main objective to guide in taking decisions for the selection of different parameters which involve the horizontal and vertical railway geometric design of high speed (HST) and long distance trains as well as theoretical concepts for describing security parameters and comfort, based on international standards. The research is developed through consultations in specialized magazines, articles, publications, standards and technical books. Due to the scarcity of data in the national language and outdated library materials, the research focuses primarily on international material. Although Brazil is a developing country with one of the highest rises in the global scene, the country has faced in recent decades serious infrastructure problems due to an uneven distribution in the area of transport, with high concentration in the road, and airports and roads operating above satisfactory capacity, resulted by a limited range of transportation alternatives. Due to the lack of investment in the railway sector, much of the Brazilian railway system became inoperative or even nonexistent, resulting in a tremendous decrease of skilled labor and academic training in this field. As a result, studies related to the railway project have also been directly impacted. In this context, it is important to rescue standards, publications, experiences and technical specifications adopted in other countries with strong tradition in railways in order to incorporate these concepts into our academic formation, which is one of the purposes of this dissertation.
26

Vysokorychlostní železnice v ČR z pohledu cestujících / High-speed Rail in the Czech Republic from the Perspective of Passengers

Kratochvíl, Petr January 2015 (has links)
This Master's Thesis deals with high-speed rail in the Czech Republic. The theoretical part describes the history, the evolution and the present of high-speed rail and presents the successful foreign high-speed rail systems. Furthermore this part presents the high-speed railway tracks which are planned in the Czech Republic. The practical part researches the perception of high-speed rail by passengers. Based on the result of the survey, which was realized via the questionnaire, it analyses the criteria that passengers consider important in the choice of means of transport and it looks into passenger willingness to accept higher fare for shorten of travel time. With using the result of the survey it also deals with competitiveness of high-speed rail compared with other modes of transport. The aim of the Thesis is determine whether high-speed rail is attractive from the perspective of passengers and whether it is able to compete with other modes of transport.

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