Florida, the fourth largest and sunshine state, is growing at the rate of 800 new residents daily.!! By the year 2000 the population is estimated to be 16 Million, and the annual tourists at 80 Million, generating 40 Million trips. The proposed High Speed Rail will connect Miami and West Palm Beach to Orlando and Tampa. This 325-mile corridor represents 70 % of all the "Socio-Economic Resources" of the whole of Florida and the trend will continue well into the next century. The Miami-Orlando ride will reduce to 2 hours speeding at up to 150 mph. It will be operational by 1995 and the system is estimated to cost 4.6 Billion Dollars. One of the major problems encountered by the new High Speed Rail (HSR) is the "RIDERSHIP FORECASTING," In the United States there is a lack of current information about the Total Volume of Intercity Trips and the Specific Characteristics of the Trips that determines a willingness to use HSR. The Quality, Comprehensiveness, and Acceptability, by the forecasts must be sufficient to generate Public Support, Confidence, and Response for the Implementation of HSR. The THESIS discusses the various Ridership Forecasting Techniques and chooses the “Most Suitable Model” applicable to conditions in South and Central Florida. A “Model Choice Based Model” is selected called, “THE LOGIT FUNCTION”, which takes into account, the Floridian Choice of available Travel Modes, and the Factors Affecting the Manner of the “Decision making Process”, in Favour of a Particular Mode. Evaluating Business and Non-Business Travel for the Internal Trips, (including the Induced Demand and the Short Trips) and the External Trips. The External and Short Trips were Not considered by Previous Studies. The standard guidelines for “Revenue and Ridership Forecasting,” by High Speed Rail Association are closely followed in this Study. Due consideration is also given to Socio-Economic data involving population, wealth, average per capita income, number of families, size of labor force, number of hotel / motel rooms and college enrollment. A Survey was carried out, to collect the data and to test the Sensitivity, under given set of conditions and scenarios. The studies conclude that HSR is a Feasible Project and by the year 2000, the Ridership will be 3.8 Million Annual Trips. The future studies will continue to improve the results, as an individual’s attitude and response towards HSR Travel becomes better known and recorded in Florida

Este trabalho utiliza uma metodologia simplificada de análise dinâmica para o estudo das vibrações em pontes ferroviárias, produzidas pela passagem de um trem de alta velocidade, associadas à presença de irregularidades nos trilhos. Iniciou-se o estudo a partir de um modelo do veículo composto por quinze graus de liberdade, referentes aos deslocamentos verticais e horizontais transversais, e rotações em torno dos eixos longitudinal, transversal e vertical. Os modelos dinâmicos do trem e da ponte foram tratados de forma desacoplada, sendo conectados pelas forças de interação trem-ponte. Desta forma, foram calculados os carregamentos provenientes da modelação dinâmica do trem, adotando-se inicialmente a hipótese de tabuleiro rígido e indeslocável e, ainda, considerando-se a presença de irregularidades geométricas nos trilhos no plano vertical. Neste trabalho, foi considerado um estudo de caso utilizando-se o modelo veicular Alfa Pendular, avaliando-se a resposta dinâmica do trem e da estrutura, considerando o efeito das irregularidades geométricas nos trilhos, bem como a presença do lastro. As forças de interação obtidas da modelagem do veículo foram aplicadas em um modelo estrutural de alta hierarquia da ponte, dividido em elementos finitos de casca, sendo que em cada nó do modelo da ponte foram especificados os esforços obtidos da análise dinâmica do veículo. Para representar a passagem do comboio sobre a ponte, foram utilizadas funções que descrevem as forças de interação trem-ponte em cada nó do modelo da ponte, em cada intervalo de tempo, até que todo o trem tenha percorrido o comprimento da ponte. A consideração de tabuleiro rígido indeslocável foi corrigida por meio de um processo iterativo, de forma que os deslocamentos do tabuleiro obtidos para a primeira determinação dos esforços de interação foram somados às irregularidades do trilho (excitação de suporte aplicada nas rodas do trem). Com isso, foi possível identificar a resposta dinâmica proveniente da carga em movimento e das irregularidades geométricas nos trilhos, avaliando o conforto dos passageiros no interior do vagão. Por fim, realizou-se uma análise de distribuição estatística para avaliar a probabilidade de se ultrapassar os limites estabelecidos pelo Eurocode. / This thesis resorts to a simplified methodology of dynamic analysis for the study of vibrations in railway bridges, produced by the passage of a high speed train, associated to the presence of irregularities in the rails. The study started from a vehicle model composed of fifteen degrees of freedom, namely, vertical and lateral displacements, and rotations about the longitudinal, lateral and vertical axes. The dynamic models of the train and the bridge were treated as uncoupled, yet being bound by the interaction train-bridge forces. Thus, the loads from the dynamic model of the train were calculated, adopting initially the hypothesis of rigid and fixed deck and also, considering the presence of geometric irregularities in the vertical track plane. In this work, we considered a case study using the Alfa Pendular vehicle model, evaluating the dynamic response of the train and the structure, considering the effect of the geometric irregularities at the tracks, as well as the presence of the ballast. The interaction forces obtained from the model of the vehicle were applied in a high hierarchy structural model of the bridge, divided into shell finite elements, specifying the forces obtained from the dynamic analysis of the vehicle at each node of the bridge model. To represent the train passage on the bridge, functions were used to describe the bridge-train interaction forces at each node of the bridge model at each time interval, until the entire train had travelled the bridge length. The consideration of rigid and fixed deck was corrected by means of an iterative process, so that the deck displacements obtained for a first determination of the interaction forces were added to the rail irregularities (excitation applied to the train wheels). Thus, it was possible to identify the dynamic response caused both by the moving loading and the geometrical irregularities of the tracks, evaluating the comfort of the passengers inside the wagon. Finally, a reliability study was carried out to evaluate the probability of exceeding the limits established by Eurocode.

To deal with an increasing demand in transportation, trains are made longer and faster. Higher speeds imply higher impacts on bridges. Therefore, structures have to be designed to resist these new constraints. The Eurocode (2002) introduced additional checks for the design of high-speed railway bridges. Among them, the maximum vertical deck acceleration criterion often determines alone the design of the structure. Tests on shake table brought to the conclusion that vertical bridge deck acceleration should never exceed 3.5 m/s2 for ballasted tracks. This master thesis investigates the optimization of cross section parameters of single-track simply supported and double-span bridges based on the limit of the maximum vertical deck acceleration criterion. The first natural frequency is considered as a proof of the feasibility of the structure. The optimization is carried out through MATLAB for both types of bridges. The deck acceleration of simply supported bridges is analytically calculated using the Train Signature (ERRI D214 1999) in MATLAB. The dynamic calculations of double-span bridges are implemented through the finite element software ABAQUS. The implemented programs have been verified by comparison to values of simple cases found in the literature. Structures are tested under the influence of the ten HSLM-A trains of the Eurocode running at speeds between 150 km/h and 350 km/h. Optimization algorithms are presented and compared in this study but their applicability in such context is questioned. Indeed, as the problem contains several suitable minima, the algorithms, which end in one solution, are not adapted. To overtake this difficulty, a scanning of the interesting zone is advised. However, the latter is very time consuming, even more if the finite element analysis is used. Suggestions to decrease analysis time are presented in this report. Single span composite bridges with a span longer than 20 m appeared to be impossible to optimize within the objectives defined in this work (i.e. considering limits of deck acceleration and first natural frequency), which draws doubts about their suitability for high-speed railways. Nevertheless, simply supported bridges made of concrete seem more adapted for high-speed railways and their optimized parameters are presented in this work. Optimized parameters for double-span concrete bridges are also presented.

published_or_final_version / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

Soil-steel composite bridge refers to structures where a buried flexible corrugated steel pipe works in composite action with the surrounding soil. These structures are being increasingly used in road and railway projects as an alternative to standard type bridges, e.g. short- and medium span concrete beam- and portal frame bridges. On account of their economic advantage and short and easy construction operation, soil-steel composite bridges are getting more popular as railway crossings located far from the cities at the heart of the nature. In this research, the dynamic behaviour of soil-steel composite bridges under high-speed train passages is studied. The studied case is a short span soil-steel composite railway bridge located in Märsta close to Stockholm. The behaviour of the bridge is first observed through field measurements in terms of deflections, stresses, and accelerations at several locations on the bridge. The measured responses are then analysed in order to predict the properties of the soil and steel material working in composite action. Subsequently, 2D and 3D finite element models are developed in order to simulate the behaviour of the bridge. The models are calibrated using the field measurements through several parametric studies. The 3D-model also enables estimation of the load distribution, which is found to increase at higher train speeds. An effective width to be used in 2D analyses is proposed. Finally, the response of the bridge is studied under high-speed train models according to Eurocode.

A damage detection approach based on Artificial Neural Network (ANN), using the statistics of structural dynamic responses as the damage index, is proposed in this study for Structural Health Monitoring (SHM). Based on the sensitivity analysis, the feasibility of using the changes of variances and covariance of dynamic responses of railway bridges under moving trains as the indices for damage detection is evaluated.   A FE Model of a one-span simply supported beam bridge is built, considering both single damage case and multi-damage case. A Back-Propagation Neural Network (BPNN) is designed and trained to simulate the detection process. A series of numerical tests on the FE model with different train properties prove the validity and efficiency of the proposed approach. The results show not only that the trained ANN together with the statistics can correctly estimate the location and severity of damage in the structure, but also that the identification of the damage location is more difficult than that of the damage severity. In summary, it is concluded that the use of statistical property of structural dynamic response as damage index with the Artificial Neural Network as detection tool for damage detection is reliable and effective.

Sedan uppstarten av Sverigeförhandlingen 2014 har diskussionen kring infrastruktursatsningar i Sverige präglats av en ny höghastighetsbana vars syfte är att sammankoppla landets tre storstäder. Sverigeförhandlingens slutrapport (SOU 2017:107) visar på att den tidsmässiga aspekten har varit en ledande faktor vid potentiella spårdragningar, där ett begränsat antal stopp har framhävts som den bästa lösningen för att spara tid. Konsekvenserna blir dock att majoriteten av de svenska kommunerna hamnar utan direkt anslutning till höghastighetsbanan. Tidigare forskning har visat att rörelse och mobilitet är en central del av människors vardagsliv; för att kunna ta oss till arbetet, träffa familj och vänner med mera. Koppling mellan mobilitet och vardag är intressant då tidigare forskning traditionellt sett har tittat på ekonomiska aspekter, spatial rättvisa och klimatfrågor gällande höghastighetståg. Höghastighetstågens inverkan på vardagslivet samt hur orter som blir utan en direkt koppling till tågen påverkas, är mindre utforskat. Därmed skall denna uppsats fylla en identifierade kunskapslucka gällande vardagslivsperspektivet i samband med planeringen av höghastighetsjärnvägar. Uppsatsen avser utreda hur planerare och politiker ser på vardagslivet och hur diskursen är strukturerad. Inom en socialkonstruktivistisk ram och med en diskursteoretisk ansats analyseras diskursen kring vardagsliv bland planerare och politiker i Ljungby ur ett mobilitetsperspektiv. Studiens empiri utgörs av intervjuer och plandokument. Under analysen framgår det att diskursen kan uppfattas som spretig där flera mindre och ingående diskurser utgör mobilitets- och vardagslivsdiskursen i Ljungby. I stora drag kretsar den kring begreppen kollektivtrafik, mobilitet och infrastruktur. Olika teknologiska möjliggörare såsom bilen, E4:an eller höghastighetsbanan har en stor inverkan på vardagslivet i Ljungby med tanke på kommunens utmaningar med kollektivtrafik och geografiska förhållanden. Samtidigt är det inte möjligt att helt fastställa en konstant definition kring mobilitets- och vardagslivsdiskursen i kommunen. Detta beror på att perspektiv, åsikter och uppfattningar är i ständig förändring och så även diskurser. Därför är syftet med uppsatsen att kartlägga denna diskursiva kamp. / Since the start of Sverigeförhandlingen in 2014, the discussion about infrastructure investments in Sweden has been characterized by a high-speed railway with the purpose of connecting the country's three major cities. Sverigeförhandlingens final report (SOU 2017: 107) concludes that the time aspect has been a leading factor in potential rail routes, where a limited number of stops has been highlighted as the best solution to save time. As a result, the majority of Swedish municipalities will end up without a direct connection to the high-speed railway. Previous research has presented movement and mobility as a central part of people's everyday lives, to be able to take us to work, meet family and friends, and so on. The link between mobility and everyday life is interesting as previous research has traditionally looked at economic aspects, spatial justice, and climate issues regarding high-speed trains. The impact of high-speed trains on everyday life and how cities without a direct connection to the trains are affected are less explored. Thus, this thesis aims to fill this identified knowledge gap regarding the everyday life perspective in connection to the planning of high-speed railways. The thesis intends to investigate how planners and politicians view everyday life and how the discourse is structured. Within a social constructivist framework and with a discourse theoretical approach, the discourse on everyday life among planners and politicians in Ljungby is analyzed from a mobility perspective. The empirical study consists of interviews and planning documents. During the analysis, it appears that the discourse can be perceived as scattered, where several smaller and in-depth discourses constitute the discourse of mobility and everyday life in Ljungby. Broadly speaking, it revolves around the concepts of public transport, mobility, and infrastructure. Various technological enablers such as the car, the E4, or the high-speed railway have a major impact on everyday life in Ljungby, given the municipality's challenges with public transport and geographical conditions. At the same time, it is not possible to fully establish a constant definition of the discourse of mobility and everyday life in the municipality because perspectives, opinions, and perceptions are constantly changing and so are discourses. Therefore, the purpose of the thesis is to map out this discursive struggle.

Changes in climate caused by changes in anthropogenic (i.e. "man-made") greenhouse gas (GHG) emissions have become a major public policy issue in countries all over the world. With an estimated 28.4% of these emissions attributed to the transportation sector, attention is being focused on strategies aimed at reducing transportation GHG emissions. Quantifying the change in GHG emissions due to such strategies is one of the most challenging aspects of integrating GHG emissions and climate change into transportation planning and policy analysis; the inventory techniques and methods for estimating the impact of different strategies and policies are still relatively unsophisticated. This research developed a method for estimating intercity passenger transportation energy and carbon footprints and applied this method to three US DOT-designated high speed rail (HSR) corridors in the U.S.-- San Francisco/Los Angeles/San Diego; Seattle/Portland/Eugene, and Philadelphia/Harrisburg/Pittsburg. The methodology consists of estimating the number of trips by mode, estimating the direct CO₂ emissions, and estimating indirect CO₂ emissions. For each study corridor the impacts of different strategies and policies on carbon dioxide emissions were estimated as an illustration of the policy application of the developed methodology. The largest gain in CO₂ savings can be achieved by strategies aiming at automobile emissions, due to its sizeable share as main mode and access/egress mode to and from airports and bus and train stations: an average fuel economy of 35.5 mpg would result in a 38-42% savings of total CO₂ emissions; replacing 25% of gasoline use with cellulosic ethanol can have a positive impact on CO₂ emissions of about 13.4-14.5%; and a 10% market share for electric vehicles would result in potential CO₂ savings of 3.4-7.8%. The impact of a 20% or 35% improvement in aircraft efficiency on CO₂ savings is much lower (0.88-3.65%) than the potential impacts of the policies targeting automobile emissions. Three HSR options were analyzed using Volpe's long-distance demand model: HSR125, HSR150, and HSR200. Only the HSR150 and HSR200 would result in CO₂ savings, and then just for two of the three corridors: the Pacific Northwest (1.5%) and California (0.8-0.9%). With increased frequency and load factors, a HSR150 system could result in CO₂ savings of 5.2% and 1.8% for the Pacific Northwest and California, respectively. This would require a mode shift from auto of 5-6%. This shift in auto mode share would mainly have to be a result of pricing strategies. From these results, HSR may not be such an obvious choice, however, with increased ridership and diversions from other modes, CO₂ savings increase significantly due to the lower emissions per passenger mile for HSR. The framework developed in this study has the ability to determine the GHG emissions for such HSR options and increased diversions.

Several of the bridges along the Bothnia railway line do not fulfill the requirements regarding vertical accelerations that are stated in current design codes. The acceleration of the bridges needs to be reduced, in order to make the Bothnia line suitable for high speed railway traffic. The aim with this thesis is to investigate if it is possible to reduce the vertical acceleration of insufficient bridges to an acceptable level by using post-installed dampers. The expectation was that this method could have major economic advantages compared to other rehabilitation methods. Five different bridges with post-installed dampers were simulated in verified MATLAB codes. The simulations were performed for two cases for each bridge: one where the eccentricities between the attachment of the damper and the centre of gravity of the bridge cross section was taken into consideration, and one where the influence from the eccentricities was excluded. The results showed that it is fully possible to reduce the acceleration to an acceptable level with the use of external damper configurations. It was also shown that the eccentricities of the bridges had a high impact in this kind of simulations. Furthermore, some supplementary investigations regarding the location and position of the damper, were done as well. Finally, a brief analysis and discussion regarding the practical implementation of the post-installed was performed. One challenge is to anchor the damper and take care of the resulting forces in a favourable and safe way. / Flertalet broar längs med Botniabanan uppfyller inte de krav som ställs på de vertikala accelerationsnivåerna i gällande dimensioneringsnormer. Dessa accelerationer måste reduceras för att göra Botniabanan tillgänglig för trafik med höghastighetståg. I denna uppsats undersöks det huruvida det är möjligt att sänka accelerationen i bristfälliga broar med hjälp av eftermonterade externa dämpare. Förväntningen var att denna metod skulle ha stora ekonomiska fördelar gentemot andra upprustningsmetoder. Fem broar med eftermonterade dämpare har simulerats i verifierade MATLAB-koder. Simuleringarna utfördes på två olika sätt för varje bro: i en kod togs eccentriciteten mellan dämparinfästningen och tyngdpunktslinjen för bron i beaktande, och i den andra koden försummades all inverkan av eccentriciteten. Resultatet från simuleringarna visade att det är fullt möjligt att reducera accelerationerna till en acceptabel nivå med hjälp av externa dämpningskonfigurationer. Eccentriciteten visade sig även ha stor inverkan på resultatet i denna typ av simulering. Dessutom utfördes några kompletterande undersökningar gällande längd, position och vinkel på dämparen. Slutligen analyserades och diskuterades den praktiska implementeringen av de eftermonterade dämparna. En utmaning är att förankra dämparna och föra ner de resulterande krafterna på ett fördelaktigt och säkert sätt.

In response to the planned increase in operational speeds and axle loads of passengertrains that may lead to resonance-induced excessive vibrations in railway bridges,recent studies examined the reliability of bridges concerning train running safety andpassenger comfort limit states. In this respect, valuable information regarding theimportance of input variables can be obtained by conducting Sensitivity Analysis (SA).For instance, the determination of unimportant variables (where they can be treated asconstant) reduces the computational time, which is usually very high for probabilisticsimulations. In some of the previous studies, only deterministic SA has beenperformed. This thesis follows a stochastic approach using Global Sensitivity Analysis(GSA) methods. The considered performance functions are vertical acceleration anddeflection of single track ballasted simply supported reinforced concrete bridges.To reduce the computational time, available semi-analytical solution of a planarbeam under the passage of a series of moving loads is employed. To simulatethe bridge behaviour realistically, simplified methods to account for rail irregularityamplification, train-bridge interactions, and axle load redistribution were adopted.The considered random variables are train modal properties, number of train coaches,bogie spacing, axle spacing and loads, bridge mass, flexural stiffness and damping,and rail amplification factor. The analyses were carried out for a selected set of bridgelengths [10-30]m and a range of train speeds [100-400] km/hr. The study findingsshow that, in both acceleration and displacement, the dynamic response of the bridgeis sensitive to randomness in bridge mass, moment of inertia, coach length, and axleloads. Furthermore, the rail amplification factor and Young’s modulus are primarilyimportant for acceleration and displacement, respectively.