Dissertations / Theses on the topic 'Steel Railway Bridge'

Many steel railway bridges in Europe are older than 50 years whilethey are subjected to higher loads than they were originally designedfor. As many of these bridges are approaching the end of their designlife it is crucial to carry out accurate fatigue assessments in order toensure their safety and keep them in service. Usually the influence ofdynamics on fatigue damage is taken into account using dynamicamplification factors from design codes whereas the actual influenceof dynamics has not been thoroughly studied.   During this study the importance of dynamics on fatigue damage isexamined on two specific examples, namely the Söderstöm Bridgeand the Åby älv bridge, which are good examples of open deckbridges that are common among steel railway bridge population.   Different train speeds, the cross beam effect and load distributionwere studied in order to assess the importance of dynamics on fatiguedamage. Three dimensional finite element models were created andlater modified to perform dynamic analysis. Moving point loads wereused to simulate the loading of moving trains. Fatigue damages werecalculated at the various locations to evaluate the influence ofdynamics on fatigue damage.   The results show that the dynamics has small influence on fatiguedamage at studied speeds and damage is not dependent on speed.Assessed cross beam effect was not detected on studied bridges interms of dynamics, but has great influence in terms of statics.

In this research a single span simply supported steel truss railway bridge is analyzed when subjected to train loads. The study was conducted by using three different methodologies namely modal analysis using three dimensional finite element models of a bridge based on As-built drawn from scratch; a time history analysis and field measurement on an existing bridge. The finite element models of the bridge were modeled using two methodologies; using beam and shell elements. A time history analysis involves developing an equation of motion for the forced and free vibration of the bridge when subjected to both a single- and successive train loads. The dynamic responses studied include the displacement, acceleration and natural frequency of the bridge which were compared for different train speeds, span length, and the mass of the bridge. Field measurement was conducted using accelerometers and displacement transducers which were mounted on a self-designed mounting section.
Dissertation (MEng)--University of Pretoria, 2015.
tm2016
Civil Engineering
MEng
Unrestricted

Interruption of railway traffic creates important financial losses for the transportation utilities and society at large. At this moment, to limit this impact, the CN uses emergency girders stored around their territory to decrease the time to transport the materials to the site. However, this method is difficult to put in place and bypass of the traffic is not possible everywhere. The development of a portable railway bridge is interesting for this purpose. This structure has to be transported, erected and in services within 48h. This type of bridge should also be adjustable in length to allow reusing of the existing bearings, piers and abutments (5 to 28m of span). Between the steel superstructure possibilities, three solutions have been chosen: (a) plate girder, (b) through girder and (c) through truss. The geometry and the construction method are the particularities to consider. After those conceptions, the three alternatives have been analyzed as a function of many criteria. The number of bolts, the quantity of material and the dimension of the prefabricated sections were considered to determine the best solution for this kind of utilization.

This paper proposes a multidisciplinary approach, combining the terrestrial laser scanner and ambient vibration tests to characterize a historical steel truss bridge in Spain: the Vilagarcia Celosia Bridge. All methods are complemented by advanced numerical simulations and a coarse to fine calibration strategy, based on the Cotter and the non-linear least squares approaches. Results obtained corroborate the robustness of the proposed approach, with a max error in frequencies of 3.6% and an average modal assurance criterion of 0.93.

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

A soil-steel composite bridge is a structure comprised of corrugated steel plates, which are joined with bolted connections, enclosed in friction soil material on both sides and on the top. The surrounding friction soil material, or backfill, is applied in sequential steps, each step involving compaction of the soil, which is a necessity for the construction to accumulate the required bearing capacity. Soil-steel composite bridges are an attractive option as compared with other more customary bridge types, owing to the lower construction time and building cost involved. This is particularly true in cases where gaps in the form of minor watercourses, roads or railways must be bridged. The objective of this master thesis is the modelling of an existing soil-steel composite railway bridge in Märsta, Sweden with the finite element software Plaxis. A 3D model is created and calibrated for crown deflection against measurement data collected by the Division of Structural Engineering and Bridges of the Royal Institute of Technology (KTH) in Stockholm, Sweden. Once the 3D model is calibrated for deflection, two 2D models with different properties are created in much the same way. In model 1, the full axle load is used and the soil stiffness varied, and in model 2 the soil stiffness acquired in the 3D model is used and the external load varied. The results are compared to measurement data. In 2D model 1 an efficient width of 1,46 m for the soil stiffness is used in combination with the full axle load, and in 2D model 2 an efficient width of 2,85 m is used for the external load, in combination with the soil stiffness acquired in the 3D model. Aside from this, parametric studies are performed in order to analyse the effect of certain input parameters upon output results, and in order to analyse influence line lengths. Recreating the accelerations and stresses in the existing bridge using finite element models is complicated, and the results reflect this. Below are shown the discrepancies between model results and measurement data for the pipe crown. The scatter in the measurement data has not been taken into consideration for this; these specific numbers are valid only for one particular train passage. For crown deflection, the 3D model shows a discrepancy of 4%, 2D model 1 5% and 2D model 2 8% compared with measurement data. For crown acceleration, in the same order, the discrepancy with measurements is 1%, 71% and 21% for maximum acceleration, and 46%, 35% and 28% for minimum acceleration. For maximum crown tensile stress, the discrepancy is 95%, 263% and 13%. For maximum crown compressive stress, the discrepancy is 70%, 16% and 46%.

Structural health monitoring is a very important phase of the maintenance of a civil work. In fact, thanks to the installation of a system able to monitor the conditions of a structure, it is possible to verify how this same structure responds to the loads to which it is subjected and to identify potentially damaged zones. Specifically, a railway bridge crossing a river undergoes stresses and deformations caused by the passage of trains, earthquake events and interactions with water. The INFRASAFE project aims to investigate all these aspects in order to guarantee a total monitoring of a specific structure - the bridge at Revere crossing Po river – in the environmental surrounding where it is placed. This research thesis is part of such project in a sense that it constitutes the preliminary analytical phase prior the experimental campaigns in the site. The truss structure will be modeled in Straus7 and a modal analysis will be performed in order to determine its frequencies and vibration modes. In addition, the axle loads of the real trains passing on the bridge will be considered for a linear static analysis. The results of such analysis will be investigated and the most stressed steel junction will be locally modeled in order to study its fatigue capacity.

A good deal of resources has been invested in building and maintaining existing infrastructure.Many structures are now becoming old and do not meet the requirements of an increasingtraffic load, or are reaching the end of their lifecycle. It is not possible or sustainable to replaceall those structures that have been judged to be obsolete or nearly obsolete. However, in manycases, their specified load carrying capacities are understated, so there is an urgent need toobtain more robust knowledge of their true status. In the design of new structures, a numberof assumptions relating to loading and structural behaviour have to be made, a number that canbe reduced by finding out more about the actual behaviour of the structure. This licentiate thesis describes the structural behaviour of existing unballasted open steel trussrailway bridges in general and methods for assessment in particular, with the aim of keepingthese structures in service for longer. An extensive program, divided into three phases of experimental studies, was carried out toincrease the understanding of existing unballasted steel truss railway bridges. Phase I consisted of instrumentation and monitoring of a 60 year-old railway bridge (ÅbyBridge) while it was still in service. A description of the object and the monitoring in thisphase of measurements is presented in Chapter 3 with some results and analysis in Chapter 4.Some of the findings from Phase I are described in Paper A, from which it was concluded thatthe stringer beams were subjected to large stresses originating from torsion and out-of-planebending. These effects are not normally considered yet may have significant consequences inrelation to fatigue. In Phase II, the former bridge over the Åby River was replaced and put beside the railwaytracks, where the instrumentation from Phase I was extended. The bridge was statically testedin 18 pre-defined load series before reaching failure. Phase II is described in Chapter 3 andsummarized in Paper B. It was found that the bridge could withstand loading corresponding tofour times the highest permitted axle-loading, or twice the design load for new bridges, beforeexhibiting an obvious non-linear behaviour with regard to vertical displacement in the midspan.The peak load was achieved at loading approximately 50% higher than the initial nonlinearbehaviour, where lateral buckling of the top chord limited the structure from carryingmore load. The failure can be concluded as being redundant without brittle failure of any ofthe connections. In Phase III, a different bridge was fitted with instrumentation and monitored while subjectedto live loading: the bridge over the river Rautasjokk. The Rautasjokk Bridge was constructedfive years later than the Åby Bridge, using the same drawings thus making it theoreticallyidentical in terms of geometry and material. It is situated along the “Ore line”, meaning that itis subjected to higher loads compared to the Åby Bridge which was located along the “Mainline”. The program for measurements originated from a code-based assessment which ruled thebridge unsafe to use with regard to fatigue of the stringers due to the gusset plates welded tothe top flange of the stringers. Paper C describes the measurement of local fatigue strains (hotspot)and comparison with nominal strains. In that paper, it was concluded that the hot-spotapproach was only favourable for one out of three studied positions, with regard to fatiguelifespan. This thesis ends with conclusions and suggestions for further research.

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.

The effective cross-section method, also called reduced cross-section method is generally used for steel in class 4 cross-sections in considering local buckling. This method is a bit complicated and time consuming, which often leads to engineers not using profiles in class 4 cross-sections. The reduced stress method is an alternative method for handling slender steel cross-sections. These two methods are described in the Eurocode, of which the latter is less described. The national annex states that the reduced stress method should not be used, however, without explanation to the general recommendation. This study is a comparison of the two different methods and is intended to provide a better understanding of the reduced stress method. The calculation process and design for steel profiles in class 4 cross-sections can in this way become more efficient. This is done by determining when it is most profitable to use the reduced stress method instead of the effective cross-section method. Thus, can the use of profiles in class 4 cross-sections become a more obvious choice in the industry. This study considered a simply supported I-beam in an open railway bridge exposed to bending moment where the same conditions were investigated for each method. The effective crosssection method is implemented by reducing the cross-sectional area and was calculated manually. In the reduced stress method, it is the yield stress that is reduced. The reduced stress method was analyzed both through FEM and manual calculations in this study. The result showed that the reduced stress method performed through FEM gave a similar result as the effective cross-section method, which makes it an appealing method. The reduced stress method with manual calculation, however, gave a more conservative result. These methods are relativelydifferent and recommendations for each method are presented in this report.
Idag behandlas ståltvärsnitt i tvärsnittklass 4 generellt med hjälp av metoden effektivt tvärsnitt för att beakta lokal buckling. Metoden är en aning komplicerad och tidskrävande, vilket leder till att konstruktörer överlag inte använder profiler i tvärsnittsklass 4. Reducerad spänning är en alternativ metod för hantering av slanka ståltvärsnitt. Dessa två metoder beskrivs i Eurokoden varav den sist nämnda mer kortfattat. I den nationella bilagan står det att metoden reducerad spänning ej bör användas dock utan motivering till det allmänna rådet. Studien är en jämförelse av de två olika metoderna och är ämnad till att ge en bättre förståelse av metoden reducerad spänning. Således kan beräkningsgången samt projektering för stålprofiler i tvärsnittsklass 4 effektiviseras. Detta genom att avgöra när det är mest lönsamt att använda reducerad spänning framför effektivt tvärsnitt. Följaktligen kan användning av profiler i tvärsnittsklass 4 bli ett mer självklart val i branschen. Denna studie omfattade en fritt upplagd I-balk i en öppen järnvägsbro utsatt för böjande moment där samma förutsättningar har undersökts för respektive metod. Effektivt tvärsnitt går ut på att reducera en tvärsnittsarea och har utförts via handberäkningar. I metoden reducerad spänning är det sträckgränsen som reduceras. I denna studie undersöktes reducerad spänningsmetoden via FEM samt handberäkningar. Resultatet påvisade att metoden reducerad spänning utförd via FEM gav ett liknande resultat som metoden effektivt tvärsnitt, vilket gör det till en attraktiv metod. Reducerad spänning via handberäkning gav dock ett mer konservativt resultat. Metoderna är relativt olika och rekommendationer för tillämpning av respektive metod presenteras i denna rapport.

The subject of this master's thesis is a static and structural design of a Load-carrying steel structure of railway bridge with bottom steel deck of the span of 42 + 60 + 42 m over the Labe river in Děčín. A solid steel beam forms the main load-bearing structure of the bridge reinforced with truss-work. The truss-work is made up of an open top chord and diagonal strut without secondary vertical struts. The calculations were done in compliance with valid ČSN EN documents.

This master thesis content is alternative design of one span single-railed steel bridge. The bridge is located in km 44,179 on the track Jaroměř - Dvůr Králové. Crossing barrier is roadway I/33. The teoretical distance between supports is 42 m. Main bearing structure is designed as Langer beam. Structure consist of beams, arcs, suspenders, bridge deck with longitudinal and transversal bracings. Elements of the structure are made out of steel S355J2+N, S235J2+N, S355NL. The bridge is designed according to current standards ČSN EN.

The thesis deals with the variant design of the steel structure of single-track railway bridge on the line Tišnov – Nové Město na Moravě. The task is bridging the local road by a bridge structure with one field. Length of the bridge is 40 m.

The subject of master’s thesis is a structural analysis of a bearing structure of an existing historical single-track railway bridge over the Vltava river in a direction from Prague Modřany to Vrané nad Vltavou. The riveted steel bridge carries rail traffic across five fields. A part of the master’s thesis is focused on a disposal of a variant of the longest field by using a modern arch construction.

The thesis deals with design and static assessment of the steel railway bridge with a span 36,6 m. The bridge is located on the two-track corridor line Košice - Púchov. It consists of two bridge structures connected by a longitudinal expansion joint. The main construction consists of four solid welded beams mounted on steel calotte bearings. The bridge deck is the top with a tub for the track bed, which is continuous at the site of the bridge. Bridging the bridge is secured by a track bed and a horizontal and lateral truss bracing. On both sides of the bridge are pedestrian walkways with a width of 1,5 m.

As rail transportation is significantly more virtuous than airplanes or cars in terms of greenhousegases emissions, its development is being encouraged in several European countries, includingSweden. In addition, the development of railway lines on which trains can travel at higher speeds ismade in Sweden with the integration of existing infrastructure. On railway bridges, an increased trainspeed potentially leads to an increase in vibrations during passage, for which the structure may not bedesigned. It is therefore essential to know the dynamic properties of the structures used.Several studies highlight the influence of friction phenomena in sliding bearings on the dynamicproperties of bridges equipped with them. This Master Thesis is based on previous works that led tothe development of a finite element modelling the friction mechanisms that occur in these bearings.The friction occurring between a PTFE sliding plate and a steel surface is thus modelled using the Bouc-Wen model, a model for hysteresis phenomena. The finite element was developed as a Fortransubroutine, which can be integrated into the finite element calculation software Abaqus as a "userdefinedelement". It allows friction to be modelled along the longitudinal direction of the bridge onlyand can therefore only be used in two-dimensional models. The user-defined element is also based ona model that takes into account the influence of contact pressure and sliding velocity on the steel-PTFEcoefficient of friction. As several studies indicate, contact temperature can also have a significantinfluence on the value of the coefficient of friction but is not taken into account in the current model.In this project, the previously developed finite element was therefore generalized to account forfriction in both directions of the sliding plate by the means of a two-dimensional generalization of theBouc-Wen model. Based on experimental data available in scientific literature, the model forcalculating the coefficient of friction was also extended to take into account the influence of thecontact temperature. In addition, a model to update the contact temperature based on the theory ofsurface heating of semi-infinite bodies has been incorporated. Finally, this thesis presents theintegration of this updated finite element on three-dimensional models of the Banafjäl Bridge, locatedin northern Sweden. Simulations to estimate the fundamental frequencies and resonance modes ofthe structure as well as the temperature increase that can occur in a bearing during the passage of atrain were carried out on this model.

The master thesis focuses on the design of a Load-carrying steel structure of railway bridge with bottom steel deck of the span of 28 + 45 + 23 m. The bridge is situated in the municipality of Třebestovice. Four variants of solution have been calculated. Two variants are made by plate main beams of variable profile, the next alternative was made by truss structure and the fourth variant consist of a combination of plate main beams with truss stiffener in the middle span. The most optimal solution was processed in detail. The calculations were done in compliance with valid ČSN EN norms.

Environmental awareness has strongly increased these last years, especially in the developed countries where societies have become increasingly preoccupied by the natural resource depletion and environmental degradation. At the same time, the increasing mass transportation demand throughout the European Union requires the development of new infrastructures. Life Cycle Assessment is increasingly used to provide environmental information for decision-makers, when a choice is to be made about the transportation mode to be implemented on a given route. In a life-cycle perspective, not only the environmental pressure of the operation of vehicles but also the burden from the infrastructure, in particular bridges as key links of the road and railway networks, has to be assessed when comparing transportation modes. Based on an extensive literature review, a simplified quantitative LCA is implemented in order to compare the environmental performance of two railway bridge designs. It is meant to be useful at an early stage in the design process, when no detailed information about the bridge is available, and when rough environmental estimations are needed. The Excel based model covers the entire life-cycle of the bridge, from raw material extraction to construction materials recycling and disposal. Various assumptions and omissions are made to narrow the scope of the analysis. For instance, processes that are found insignificant in the literature are omitted, and only a limited set of relevant emissions and impacts to the environment is considered. The model provides fully transparent results at the inventory and impact assessment level. The streamlined approach is tested by comparing the environmental burden throughout the life-cycle of a steel-concrete composite railway bridge on a single span, equipped with either a ballasted or a fixed concrete single track. The results show that the environmental impacts of the fixed track alternative are lower than that of the ballasted track alternative, for every impact categories. In a sustainable development perspective, it would thus have been preferable to install a fixed track over the bridge to reduce its overall impact on the environment by about 77%. The raw material phase is found decisive in the life-cycle of both alternatives. The frequency of the replacement of the track is identified as a key environmental parameter, since the road traffic emissions during bridge closure nearly overwhelmed the other life-cycle stages.

The subject of this diploma thesis is static verification steel structure of exist railway bridge in accordance with the valid standards. The bridge have three simple spans with a span of 25; 98 and 25 meters, outer fields are simple beams, the middle field is the beam reinforced with an arch with vertical rods. Steel orthotropic deck with longitudinal stiffeners and crossbeams. Further were designed and analyse other possible options super structure of the middle field, and the resulting variant as a circle span with radial rods was detail solved and made documentation.

Railway noise is a very important and growing health hazard in today´s society.Railway systems pass through towns and cities and create noise. When trainsride through or over railway bridges, switches and crossings the noise increasessubstantially, causing great annoyance to the residents in the area.At the present time, acoustic regulations exist in most countries and are set to achievea good environmental quality in residential areas, schools, hospitals, offices andhotels.A few calculation models exist for railway traffic noise, such as The NPM 1996,NORD2000 and Cnossos-EU. The NPM 1996 is currently used in Sweden to calculatenoise propagation from railway traffic. To uphold the regulations set, it is importantthat the method used is as precise as possible. All of these calculation modelsare based on several correction factors. Today, the current corrections for trackconditions, that is railway bridges, switches and crossings, are not very accurate andneed to be reconsidered.The aim of this project was to investigate and quantify the error of the NPM correctionfactors and give some indication of how they should be adjusted. This is done to makethe noise prediction from railway traffic more accurate and thus protect the residentsfrom these health risks.The specific objective was to perform significant amount of field measurements ofnoise from trains on different steel bridges, switches and crossings, as well as on afew concrete bridge according to the measurement standard Nordtest NT 098. Thefield work was carried out over the period March to May, when weather conditionsmet the criteria for field measurements, in and around the Stockholm area.The results obtained revealed that the correction factors for steel bridges andcrossings are considerably lower in the NPM than measured in this project. However,the correction factors for switches and concrete bridges are similar to the ones inthe NPM. In this thesis, a part of the correction factors have only been invalidatedto a degree. It has been shown that each bridge is unique and perhaps there is apossibility of finding similarities between some type of bridges. However, much moreiv |measurements are needed to see any correlation between each bridge type. Thus,further and more comprehensive measurements have to be carried out in order toestablish new accurate correction factors for track conditions in the Nordic PredictionMethod.

For almost one hundred years, Brno has been deciding where the place of a new main train station should be. The works have almost started several times, but the various affairs have always postponed it. Two years ago, it was finally decided that „the River option“ would be constructed. So far, only the technological template has been written – e. g. railway bridge or platforms outline. The thesis focuses on the architectural design of the main building, the roof construction above the railways and spaces below the station bridge. In the design, the outlying urban structures are also dealt with. These include the locations of a bus station, taxi services and bike stands. Moreover, the design also mentions the station’s connection to the city networks. The main motive of the design is to put the main train station building into the centre of the city’s attractions – to make it visible. A boulevard’s view is oriented to the St. Peter’s cathedral – a famous Brno’s building. Just as the mentioned cathedral, the station is important for the city and deserves to be seen. A strong arched construction on four pillars serves as a roof over the railways and places where most visitors are expected to be most of the time. The arch also connects the public transport lines and the bus station. Part of a roof shaped like waves around the main hall connects the structure with the riverside nearby.

碩士
中華科技大學
土木防災工程研究所
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This research focused on a continuous steel truss curved railway bridge structure analysis in the planning: preliminary design and detailed design stages, by using SAP90 structure analysis software program, established two-dimensional and three-dimensional model and compare the results. In addition to the railway bridge eastbound and westbound track, there are a total of three track live load lanes included cargo track. The steel truss curved railway bridge style is fitted with the mechanical behavior of three-span continuous structures. There is no similar domestic bridge, hoping to be able to provide a reference for the future bridge design.

Steel railway bridges are vital members of railway and transport infrastructures, worldwide. These bridges are exposed to various external effects, such as high levels of dynamic train loads as well as adverse environmental impacts that cause them damage during the time. In the rail industry, conventional physical and expensive inspections are carried out to monitor all types, extents, and degrees of damage. The effectiveness of the physical inspection, however, is always compromised by limited human resources, the delayed discovery of damages, lack of knowledge, and subjectivity of inspectors. In recent years, structural engineers and researchers have focused on vibration-based damage detection approaches to fill the existing gaps due to the low effectiveness of conventional railway bridge inspections. Generally, vibration-based damage detection approaches are categorized into two types; conventional and modern. The conventional approaches rely on vibration responses of structures e.g. derived by changes of natural frequencies and mode shapes due to damage while the modern approaches include data-driven methods that use signal processing, and then artificial intelligence such as machine learning techniques to formulate the relationship between the change of structural properties due to damages to finally diagnose and prognosticate them. This thesis focuses on the modern application i.e. machine learning techniques to detect damages in operational steel railway bridges using vibration data collected from practical field testing. As the operational bridges are real in-service structures and no actual damage can be applied to them, extensive efforts are made to develop close Finite Element (FE) models from the studied real bridges and to validate them with the extracted modal parameters of the bridge using the FE model validation techniques in the modal and transient dynamic analyses to ensure the incorporated damages into these FE models can capture any change of structural modal parameters due to damages with good approximation. In addition, the work completed in this thesis advances both fundamental understandings and applied knowledge on vibration-based structural damage or anomaly detection methods using machine learning applications such as Support Vector Machine (SVM) and k-Nearest Neighbors (kNN)s to more advanced deep learning approaches such as Convolutional Neural Networks (CNN)s and Siamese Convolutional Neural Networks (SCNN)s. Machine learning applications employ complicated signal processing to manually extract complex Damage Sensitive Features (DSF)s. Appropriate machine learning approaches to detect damages and advanced deep learning applications are developed in such a way that completely removes requirements for complicated signal processing or manual DSF extraction before detecting damages to increase the speed and effectiveness of the damage detection process. The novel development of the application of advanced generalized vibration-based deep learning for the anomaly detection of not only a single bridge but also a group of bridges with various lengths and configurations pushes the boundaries of structural damage detection techniques a step closer to a fully practical data-driven tool for the damage detection of a real bridge network using an integrated, centralized and all-in-one SCNN tool for a real-life Structural Health Monitoring (SHM) of the in-service strategic railway bridges.
Thesis (Ph.D.) -- University of Adelaide, School of Civil, Environmental & Mining Engineering, 2022