Trafikverket, the Swedish Transport Administration, has been commissioned by the Swedishgovernment to make plans for new railway mainlines between the country’s three largest cities:Stockholm and Gothenburg/Malm¨o. The planned operating speed of the new mainlines isbetween 250–320 km/h. Train traffic at such high speeds across areas with soft soils may lead tolarge amplifications of the train induced ground vibrations, a phenomenon known as the groundvibration boom. The first observation of this phenomenon in practice occurred in Sweden in 1997,at the site Ledsg˚ard on the West Coast Line. This observation led to extensive investigationsand research. One of the research projects consisted of the development of the numerical calculationsoftware VibTrain by the Norwegian Geotechnical Institute, through which high speedtrain induced ground vibrations could be analyzed.The aim of this thesis has been to investigate whether VibTrain also could be used in planningworks for the new mainlines, specifically with respect to (i) evaluating the risk of the groundvibration boom and (ii) designing soil improvement measures. The investigation was conductedthrough calculations using the VibTrain software in three separate parts: (i) a verification of Vib-Train’s function on a modern computer by comparison with previous analyses for the Ledsg˚ardcase, (ii) a parametric study of the calculation model used in VibTrain and (iii) a comparison ofresults from VibTrain with results from the calculation software ωFE-N (¨Ulker-Kaustell 2016)for the location J¨arnasl¨atten in Ostl¨anken, a section of the new mainlines.The main findings from these calculations were:• The use of VibTrain on a modern computer worked well, and the verification of the program’sfunction through comparison with the Ledsg˚ard case yielded consistent results.• Modeling of soil improvement measures in the form of lime cement columns in VibTrain,using the method of equivalent modulus, gave results which principally agreed with theexpected behavior.• The comparison with results from the calculation software ωFE-N showed that the twoprograms agreed relatively well for a case with unimproved subgrade. In the analyzedcases with improved subgrade there were larger discrepancies, due to different modelingstrategies being used in the two programs.Based on the performed calculations, it is evident that VibTrain is best suited for initial assessmentsof the risk of the ground vibration boom. However, the calculation model is not sufficientlydetailed to be used in the design of soil improvement measures for the subgrade.

Higher speeds and higher capacity will cause the Swedish rail network to be exposed to disturbing dynamic effects. Higher speeds cause higher vertical acceleration levels of the bridge deck. In this thesis, a numerical analysis of a three span end-frame bridge subjected to train induced vibrations is performed. The aim is to identify which structural components and boundary conditions that affect the dynamic behavior of the bridge. Furthermore, the influence of soil structure interaction (SSI) will be investigated as it may have contribution to the stiffness and damping of the structural system.  In order to capture the dynamic response of the bridge, an analysis in the frequency domain was preformed where frequency response functions (FRF) and acceleration envelopes were obtained. For this purpose, a detailed FE-model in 3D was created. Three different cases were studied, model subjected to ballast, model subjected to soil and model subjected to both ballast and soil in coherence. A high speed load model (HSLM) was used to create simulation of train passages at different speeds and applied to all cases so that the bridge deck accelerations could be studied. A simplified 2D-model with impedance functions representing the soil-structure interaction was created to validate the results from the detailed 3D-model and for practical design purposes.  The result of this numerical analysis showed that the vertical accelerations were within acceptable levels of the maximum allowed limits given in governing publications. Considering the surrounding soil, the results revealed an increase of the dynamic response in the midspan at resonant frequency. However, it was identified that this behavior is not explained by the influence of soil structure interaction but rather the change in boundary conditions of the end-shields. The same dynamic behavior was identified for the simplified 2D-model, with a slight underestimation of the vertical accelerations at resonance.

The increasing need for High-Speed Railway (HSR) to reduce the travelling time requires increasing research within this field. Bridges are main components of any railway network, including HSR networks, and the optimization of their design for this purpose would contribute to a faster and more cost effective development of the HSR network. The initial investment, the running and maintenance costs of the bridges can be decreased through better understanding of the their dynamic behaviour. This thesis studies the dynamic behaviour of end-shield railway bridges under HSR operation. 2D beam analysis is used to study the effect of the distribution of the train’s axle load. Relatively accurate 3D FE-models are developed to study the effect of Soil-Structure Interaction (SSI) and the dynamic response of the bridges. Modelling alternatives are studied to develop an accurate model. A full scale test of a simply supported Bridge with end-shields using load-controlled forced excitation was performed and the results were used to verify the theoretical models. A manual model updating process of the material properties of the 3D FE-model is performed using FRFs from the field measurements. A Simple 2D model is also developed, where a spring/dashpot system is implemented to simplify SSI, and updated to reproduce the field measured responses. The conclusions of the project emphasize the importance of SSI effects in the dynamic analysis of end-shield bridges for predicting their dynamic behaviour. The conclusions also show that the modelling of the surrounding soil and the assumption of the soil material parameters have significant effect on the dynamic response. Even the boundary conditions, bedrock level and the ballast on the railway track affects the response. The results also show that the bridge’s concrete section behaves as uncracked section under the studied dynamic loading. / <p>QC 20170403</p>

High-Speed Railway (HSR) technology requires the deployment of noise barriers to mitigate noise pollution affecting nearby residents. As train speeds increase, so does the magnitude of aerodynamic effects such as aerodynamic noise and the pressure on these barriers, meaning that these structures require robust sound insulation and structural load-bearing capacities. Train-induced aerodynamic loads must therefore be accounted for in the structural design of HSR noise barriers, and accurate characterization of these loads is vital for ensuring noise barrier performance and safety. Current European standards primarily evaluate aerodynamic loads on noise barriers based on train speed and the distance to the track centre. However, geometric differences between high-speed trains (HSTs) from different countries and regions necessitate the validation and potential revision of existing load calculation models. This thesis aims to enhance the characterization of train-induced aerodynamic pressure on HSR noise barriers and develop more accurate models for its calculation, focusing on the most common barrier type—vertical noise barriers. Initially, a thorough literature review was conducted to assimilate current knowledge on this topic and pinpoint existing gaps and challenges. Multiple factors including the geometric properties of trains and the heights of noise barriers were then analysed using computational fluid dynamics (CFD) simulations to evaluate their impact on the train-induced aerodynamic pressure on vertical noise barriers. Finally, the suitability of existing pressure calculation models was evaluated using literature data and a modified calculation model building on the EN 14067-4 model was developed.  A key finding is that the general applicability of existing pressure calculation models is limited because of the wide variation in HST geometries and noise barrier heights. The amplitude of train-induced aerodynamic pressure on vertical noise barriers increases with train height and width but decreases as nose length increases. While taller noise barriers experience greater aerodynamic pressures, the in-crease in pressure with barrier height is not significant. The proposed modified pressure calculation model that accounts for train geometry and the height distribution coefficient predicts the train-induced aerodynamic pressure on vertical noise barriers more accurately than existing models and could thus improve the structural design and safety of HSR noise barriers across a wide range of conditions.

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.

Cette thèse analyse les tendances mondiales dans le financement de grands projets d'infrastructure dans le secteur des transports, en identifiant les caractéristiques distinctives du financement dans les pays développés et en développement. Un nouveau mécanisme de financement est proposé dans le contexte de contraintes budgétaires strictes grâce à l'utilisation d'un certain nombre d'effets économiques indirects découlant de l'amélioration de l'accessibilité des différents territoires en matière de transport. Comme le sujet de l'analyse, il y avait un projet de la construction d'un chemin de fer à grande vitesse en Russie Moscou-Kazan. / This paper analyzes global trends in financing large infrastructure projects in the transport sector, identifying the distinctive features of financing in developed and developing countries. A new financing mechanism is proposed in the context of strict budgetary constraints through the use of a number of indirect economic effects arising from improved transport accessibility of individual territories. As the subject of the analysis, there was a project of the construction of a high-speed railway in Russia Moscow-Kazan.

In this thesis, the influence of soil-structure interaction (SSI) of end-frame bridges for high-speed railways was studied. Impedance functions, representing the SSI, was calculated and analyzed. The impedance functions were applied to end-frame bridge models which were analyzed for use in HSR. A new high-speed railway link is currently being planned in Sweden by the Swedish Transport Administration (Trafikverket). \textit{Ostl\"{a}nken} is planned to run between the cities of Stockholm and Link\"{o}ping with a maximum speed limit of 320km/h. As high-speed traffic induces high dynamic impact on bridges, dynamic analysis to ensure safety and passenger comfort is needed according to Eurocode. Thus, there is a demand of dynamically safe bridges that are also cost-effective. One cost-effective bridge is the soil integrated end-frame bridge, however, there are no design advice in Eurocode today on how to take SSI into consideration. The aim of the thesis has therefore been to investigate if the influence of SSI on end-frame bridges for HSR. This thesis was executed using the frequency domain approach to solve dynamic problems in finite element software. Furthermore, impedance functions have been obtained representing the SSI. Impedance functions take dynamic stiffness and dynamic damping into consideration where the damping consists of two parts: material damping and radiation damping due to energy dissipation in the form of elastic waves. To limit the model size, an absorbing region (AR) was used to mitigate waves originating from the source. The accuracy of impedance functions is dependent on several parameters and demands a great computational capacity to reach, mostly governed by the radiation condition. A parameter study of impedance functions was conducted, including parameters such as geometry, modulus of soil and detail levels. The impedance functions were then attached to bridge models on which trains modelled as moving point loads were applied. Envelopes of the acceleration and displacements have been presented and analyzed. Shear strain checks were made in order to verify the assumption of linear-elastic material behavior of the embankment. By using SSI in form of impedance functions attached to bridge models, numerical results show a great reduction of vibrations in models. The study suggests that a large end-frame, either long or high or both, may reduce acceleration as well as displacements. A stiffer embankment material may further reduce vibrations. Shear strain checks confirm that the assumption of linear-elastic soil behavior was true. / I det här exjobbet har påverkan av jord-struktur interaktion (soil-structure interaction - SSI) av ändskärmsbroar för höghastighetsbana blivit studerat. Impedansfunktioner som representerar SSI har beräknats och analyserats. Impdansfunktionerna har sedan applicerats på bromodeller och analyserats för höghastighetstrafik. Sveriges första höghastighetsbana håller just nu på att planeras av Trafikverket. Ostlänken kommer att bli den första delen och är planerad att gå från Stockholm till Linköping med en högsta hastighet av 320 km/h. Då höghastighetstrafik introducerar stor dynamisk på verkan på broar behövs dynamisk analys genomföras enligt Eurocode för att kunna säkerställa broarnas säkerhet och komfortkrav. Därför finns idag ett behov av dynamiskt säkra broar som också är kostnadseffektiva. En typ av kostnadseffektiv bro är den med jord integrerade ändskärmsbron. I dagens Eurocode finns dock inga konstruktionsråd vad gäller jord-struktur interaktion av ändskärmarna. Målet med detta examensarbete har därför varit att undersöka påverkan av SSI och besluta huruvida användandet av ändskärmsbron på höghastighetsbanor är legitimerat, eller om den ska undvikas. Det här examensarbetet har utgått från att lösa dynamiska problem i frekvensdomänen med hjälp av FEM. Impedansfunktioner som representerar jord-struktur interaktionen har tagits fram. Impedansfunktioner tar dels hänsyn till dynamisk styvhet och dels dynamisk dämpning. Den dynamiska dämpningen består av två delar; den första är materialdämpning och den andra är vågdämpning där energi dissiperar i vågform. För att begränsa FE modellens storlek har en absorbing region tillämpats för att absorbera vågorna vid randen. Impedansfunktionernas konvergens beror på flertalet parametrar och kräver en hög datakapacitet för att fås, mestadels beroende av radiatorvillkoret. En parameterstudie utfördes för att kunna analysera sensitiviteten hos impedansfunktionerna. Vidare applicerades dessa impedansfunktioner på skal- och balk-bromodeller på vilka HSLM laster påfördes. Skjuvtöjningskontroller gjordes för att verifiera att antagandet om linjärelastiskt materialbeteende var korrekt. Genom att ta hänsyn till SSI i form av impedansfunktioner tyder numeriska resultat på att vibrationer kan reduceras i hög grad. Envelopper visar att en stor ändskärm, antingen lång, hög eller bådadera, kan reducera accelerationer liksom förskjutningar. En styvare bank kan ytterligare reducera vibrationer.

This research aims to analyse the dynamic behaviour of Soil-Steel Composite Bridges when subjected by high-speed trains. the analyses of the dynamic response for these structures are needed since there is little research performed in the present field of knowledge. Since there is also in need to perform separate dynamic analysis for these structures to verify their dynamic response, the dynamic behaviour must be analysed. The research are performed in 2D FE-models in the commercial FE-program Brigade/PLUS since there is of interest to analyse if simplified 2D-models can predict the dynamic behaviour for these structures and verify against design criterions in regulatory documents. The research is performed by calibrating a reference model against collected field measurements from a constructed Soil-Steel Composite Bridge, SSCB, located in Märsta, Sweden, Märsta Bridge. The calibration process was made to ensure satisfactory results before continuing the research by analysing a future planned SSCB in a case study that is known to in the future be subjected by high-speed trains. The future planned bridge is the Björnbo Bridge located in Skutskär, Sweden. A static structural design is first made with existing methods to verify Björnbo Bridge for static load cases. Attempts is made to verify the Björnbo Bridge against dynamic criterions available in Eurocode documents and Swedish Transport Administration regulatory documents, which includes verifying accelerations limits for 10 different high-speed trains. Smaller analysis of fatigue for the Märsta Bridge and the Björnbo Bridge was also made to verify dynamic stresses from giving fatigue damages. Since the research is limited for SSCB for dynamic cases, parametric studies are performed for certain parameters identified from an international literature review of earlier studies in both static and dynamic analysis. The studied parameters are: Soil cover depth, Young's modulus for engineered backfill and different profiles impact. These parametric studies are made to be able to understand influence and sensitivities from the analysed parameters with the long-term goal to develop analysis methods and verifications for SSCB for dynamic load situations. The calibrated reference model showed that there are difficulties in calibrating acceleration levels that agrees with the field measurements from Märsta Bridge. The expected result from the analysis of the Björnbo bridge was to fulfil static structural design criterions and that the acceleration limits were below serviceability criterions for dynamic analysis according to Eurocode documents. Moreover, that the stresses did not give fatigue damages. From parametric studies, it has shown that the governing parameter is the Young's modulus for engineered backfill, which affects estimated accelerations in a fashion that was not expected in the beginning. The presumption to perform dynamic analysis with 2D FE-models has shown that all aspects that is needed to verify cannot be performed, such as bending in two directions or twisting mode shapes. Thus, there is in need to find ways to perform dynamic analysis for SSCB with efficient 3D-models. / Denna avhandling syftar till att undersöka det dynamiska beteendet hos rörbroar när dem belastas med höghastighetståg. Analyser av den dynamiska responsen för dessa konstruktioner är behövlig då det finns lite forskning som utförts inom kunskapsområdet. Då man även behöver genomföra separata dynamiska analyser för dessa konstruktioner för att verifiera  deras dynamiska beteende, så är det ett behov av att dess dynamiska beteende analyseras. Undersökningen är genomförd med FE-modeller i 2D i det kommersiella FE-programmet Brigade/PLUS då det är av intresse att analysera om förenklade 2D-modeller kan forutse det dynamiska beteendet för dessa konstruktioner och verifiera konstruktionen mot kriterier ställda i styrande dokument. Undersökningen genomförs genom att kalibrera en referens modell mot insamlade fältmätningar från en konstruerad rörbro i Märsta, Sverige, Märsta rörbro. Kalibreringsprocessen genomförs för att försäkra att godtagbara resultat erhålls innan undersökningen fortsätter med att analysera en planerad rörbro i en fallstudie som kommer belastas av höghastighetståg. Den planerade rörbron är Björnbo rörbro som skall konstrueras i Skutskär, Sverige. En statisk konstruktionsberäkning med befintliga metoder är först utförd för att erhålla dimensioner och verifiera Björnbo rörbro för ett statiskt lastfall. Därefter utförs försök att verifiera Björnbo rörbro mot dynamiska villkor tillgängliga i Eurokod och Trafikverkets styrande dokument, detta inkluderar att verifiera accelerationsnivåer för 10 olika höghastighetståg. Mindre analyser genomförs även för utmattning för Märsta rörbro och Björnbo rörbro för att verifiera den dynamiska spänningshistoriken inte orsakar utmattningsskador. Då forskningen är begränsad gällande dynamiska studier för rörbroar, så utförs även parametriska studier för parametrar identifierade från en internationell litteraturinventering av tidigare studerade fall för rörbroar gällande både statiska och dynamiska analyser. Dom studerade parametrarna är: Överfyllnadshöjd, Jordmodul för kringfyllning och olika profilers inverkan. Dessa parametriska studier är utförda för att förstå influensen och känsligheten i dessa parametrar med det långsiktiga målet att utveckla analysmetoder för att verifiera rörbroar även för dynamiska situationer. Den kalibrerade modellen visade att det var svårigheter att kalibrera in accelerationsnivåer som överensstämde med fältmätningar från Märsta rörbro. Det förväntade resultatet från Björnbo rörbro var att uppfylla statiska konstruktionsvillkor och att uppfylla accelerationskrav för bruksgränstillståndet för konstruktionen. Samt att kunna verifiera att utmattningen inte skulle utgöra ett problem. Från dom parametriska studierna så har det visat att den styrande parametern är jordmodulen för kringfyllningen, den påverkar accelerationsnivåer som inte var förväntat vid undersökningens påbörjan. Antagandet att utföra de dynamiska analyserna med 2D FE-modeller har visat att alla aspekter som ska verifierasinte kan utföras, så som böjande moment i två riktningar eller vridande mod former. Således, så finns ett behov av att finna vägar att utföra dynamiska analyser för rörbroar i effektiva 3D-modeller

Main topic of this Masters Thesis is design of railway station for high speed line railway. Building site is situated in East Moravian region in the district of Brno-Tuřany. The building is designed as a detached two-storey object standing on the bridge over the railway. Mass of the building consists of two trimmed blocks which are mutually mirrored. The mass of both parts of the building is pervaded by illuminating stripe. Its shape is also based on the shape of trimmed block and rises over the surrounding surfaces. There are placed vertical paths in the stripes. It helps passengers in orientation because these are visible even from the outside of the building. This arrangement of individual masses symbolizes both direction of the arrival of trains to the station. There is placed arrival and departure hall in the middle of the object. Its height is similar to the height of the object itself. The hall is surrounded by the service facilities of the railway station situated on two floors. The supporting structure is made of steel. Both peripheral housing and roof are supported by the frame construction consisting of planar lattice beams. Construction of the façade is composed of frame system Wicona. The peripheral housing is tiled with panels of expanded metal.

Increasing the operational speed of trains has attracted a lot of interest in the last decades and has brought new challenges, especially in terms of infrastructure design methodology, as it may induce excessive vibrations. Such demands can damage bridges, which in turn increases maintenance costs, endangers the safety of passing trains and disrupts passenger comfort. Conventional design provisions should therefore be evaluated in the light of modern concerns; nevertheless, several previous studies have highlighted some of their shortcomings. It should be emphasized that most of these studies have neglected the uncertainties involved, which preventsthe reported results from representing a complete picture of the problem. In this respect, the present thesis is dedicated to evaluating the performance of conventional design methods, especially those related to running safety and passenger comfort, using probabilistic approaches. To achieve this objective, a preliminary study was carried out using the first-order reliability method for short/medium span bridges passed by trains at a wide range of operating speeds. Comparison of these results with the corresponding deterministic responses showed that applying a constant safety factor to the running safety threshold does not guarantee that the safety index will be identical for all bridges. It also shows that the conventional design approaches result in failure probabilities that are higher than the target values. This conclusion highlights the need to update the design methodology for running safety. However, it would be essential to determine whether running safety is the predominant design criterion before conducting further analysis. Therefore, a stochastic comparison between this criterion and passenger comfort was performed. Due to the significant computational cost of such investigations, subset simulation and crude Monte-Carlo (MC) simulation using meta-models based on polynomial chaos expansion were employed. Both methods were found to perform well, with running safety almost always dominating the passenger comfort limit state. Subsequently, classification-based meta-models, e.g. support vector machines, k-nearest neighbours and decision trees, were combined using ensemble techniques to investigate the influence of soil-structure interaction on the evaluated reliability of running safety. The obtained results showed a significant influence, highlighting the need for detailed investigations in further studies. Finally, a reliability-based design optimization was conducted to update the conventional design method of running safety by proposing minimum requirements for the mass per length and moment of inertia of bridges. It is worth mentioning that the inner loop of the method was solved by a crude MC simulation using adaptively trained Kriging meta-models. / Att öka tågens hastighet har väckt stort intresse under de senaste decennierna och har medfört nya utmaningar, särskilt när det gäller broanalyser, eftersom tågen inducerar stora vibrationer. Sådana vibrationer kan öka underhållskostnaderna, äventyra säkerheten för förbipasserande tåg och påverka passagerarkomforten. Konstruktionsbestämmelser bör därför utvärderas mot bakgrund av dessa problem; dock har flera tidigare studier belyst några av bristerna i dagens bestämmelser. Det bör understrykas att de flesta av dessa studier har försummat de osäkerheter som är involverade, vilket hindrar de rapporterade resultaten från att representera en fullständig bild av problemet. I detta avseende syftar denna avhandling till att utvärdera prestandan hos konventionella analysmetoder, särskilt de som rör körsäkerhet och passagerarkomfort, med hjälp av sannolikhetsmetoder. För att uppnå detta mål genomfördes en preliminär studie med första ordningens tillförlitlighetsnmetod för broar med kort/medellång spännvidd som passeras av tåg med ett brett hastighetsspektrum. Jämförelse av dessa resultat med motsvarande deterministiska respons visade att tillämpa en konstant säkerhetsfaktor för verifieringen av trafiksäkerhet inte garanterar att säkerhetsindexet kommer att vara identiskt för alla broar. Det visar också att de konventionella analysmetoderna resulterar i brottsannolikheter som är högre än målvärdena. Denna slutsats belyser behovet av att uppdatera analysmetoden för trafiksäkerhet. Det skulle emellertid vara viktigt att avgöra om trafiksäkerhet är det dominerande designkriteriet innan ytterligare analyser genomförs. Därför utfördes en stokastisk jämförelse mellan detta kriterium och kriteriet för passagerarkomfort. På grund av den betydande. analystiden för sådana beräkningar användes delmängdssimulering och Monte-Carlo (MC) simulering med metamodeller baserade på polynomisk kaosutvidgning. Båda metoderna visade sig fungera bra, med trafiksäkerhet som nästan alltid dominerade över gränsningstillståndet för passagerarkomfort. Därefter kombinerades klassificeringsbaserade metamodeller som stödvektormaskin och beslutsträd genom ensembletekniker, för att undersöka påverkan av jord-brointeraktion på den utvärderade tillförlitligheten gällande trafiksäkerhet. De erhållna resultaten visade en signifikant påverkan och betonade behovet av detaljerade undersökningar genom ytterligare studier. Slutligen genomfördes en tillförlitlighetsbaserad konstruktionsoptimering för att föreslå ett minimikrav på erforderlig bromassa per längdmeter och tröghetsmoment. Det är värt att nämna att metodens inre loop löstes med en MC-simulering med adaptivt tränade Kriging-metamodeller. / <p>QC 20210910</p>