Condition monitoring of wooden railway sleepers applications are generallycarried out by visual inspection and if necessary some impact acoustic examination iscarried out intuitively by skilled personnel. In this work, a pattern recognition solutionhas been proposed to automate the process for the achievement of robust results. Thestudy presents a comparison of several pattern recognition techniques together withvarious nonstationary feature extraction techniques for classification of impactacoustic emissions. Pattern classifiers such as multilayer perceptron, learning cectorquantization and gaussian mixture models, are combined with nonstationary featureextraction techniques such as Short Time Fourier Transform, Continuous WaveletTransform, Discrete Wavelet Transform and Wigner-Ville Distribution. Due to thepresence of several different feature extraction and classification technqies, datafusion has been investigated. Data fusion in the current case has mainly beeninvestigated on two levels, feature level and classifier level respectively. Fusion at thefeature level demonstrated best results with an overall accuracy of 82% whencompared to the human operator.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

A three part investigation into the effects of riparian reforestation on small streams demonstrated the timing, nature, and processes of morphologic change. First, measurements of two small streams in northeastern Vermont collected in 1966 and 2004 – 2005 documented considerable change in channel width following a period of passive reforestation. Channel widths of several tributaries to Sleepers River were measured in 1966 when the area had more non-forested riparian vegetation than today. A longitudinal survey in 2004 of two of these tributaries, followed by detailed measurements at specific reaches in 2005, provided information on channel size, large woody debris (LWD), and riparian vegetation. Reforested reaches have widened and incised markedly since 1966. Reaches with the oldest forest were widest for a given drainage area, and the non-forested reaches were substantially narrower. A conceptual model was developed that describes a multi-phase process of incision, widening, and recovery following riparian reforestation of non-forested areas. Second, a fixed-bed hydraulic model of one of the streams was developed to evaluate the impact of forested riparian vegetation on near-bank turbulence during overbank flows. Flume experiments with kinematic similitude and a 1:5 scale represented half a channel and its floodplain, mimicking the size of a non-forested reach. Two types of vegetation were simulated: non-forested, with synthetic grass carpet; and forested, where wooden dowels were added. Three-dimensional velocities were measured with an acoustic Doppler velocimeter. Velocities, turbulent kinetic energy (TKE), and Reynolds shear stress showed significant differences between forested and non-forested runs. Forested runs exhibited a narrow band of high TKE in the near-bank region that was roughly two times greater than in non-forested runs. Hydraulic characteristics of forested runs appear to create an environment with higher erosion potential, thereby indicating a possible driving mechanism for channel widening in reforesting stream reaches. Third, Light Detection and Ranging (LiDAR) data from Chittenden County were analyzed to develop a method capable of classifying riparian buffers into broad classes according to forest type and age. The geospatial characteristics of the LiDAR data in forested areas were explored using semivariogram analysis, and LiDAR-based metrics were derived in a geographic information system (GIS) to quantify vegetation height and variance. The LiDAR-based metrics were then used in two discriminant analysis procedures that distinguished: 1) forest type as deciduous or coniferous; and 2) forest age in four age classes. With the resulting linear discriminant functions, a GIS-based classification method was developed. The classification method was highly successful at determining forest type but only moderately successful at determining forest age.

Acid deposition forms when emission-derived sulfur dioxide and nitrogen oxides interact with precipitation and was particularly severe in the northeastern US. Effects of acid deposition include declining soil quality due to low pH and base cation leaching, which subsequently altered the composition of soil solution, ground water (GW) and eventually stream water. Because of the high buffering capacity of carbonates, watersheds underlain by carbonate rich rocks have received limited attention in acid deposition studies, however, carbonate weathering by strong anthropogenic acids can increase atmospheric CO2 levels. Emission reductions due to the Clean Air Act and Amendments has led to a substantial reduction of acid deposition and many ecosystems are now recovering and stream water exports contain lower concentrations of acid anions and base cations. However, the effects of recovery on watershed soil, soil solution, and GW composition, which potentially varies with landscape position, are not well constrained. The objective of this study was therefore to investigate links between soils and water composition in a watershed with important carbonate contents in the underlying rock, the Sleepers River Research Watershed (SRRW), using long-term datasets that span the recovery period. Temporal trends (1991-2015) for acid anions (sulfate and nitrate), pH, base cations (Ca, Na) and Si were investigated for stream water and trends with time, depth, and landscape position (hilltop, hillslope, and riparian zone) for the same solutes were assessed in GW and soil solution (2004-2013). Furthermore, soil elemental composition and mineralogy in archived (1996) and modern (2017) soil samples were analyzed to investigate changes in soil composition due to base cation leaching and carbonate weathering with time and landscape position. Results indicate that SRRW is indeed recovering from acidification as evidenced by declining sulfate content and rising pH in stream water, GW, and soil solution. Additionally, Ca typically derived from carbonate weathering decreased progressively with time in GW and showed signs of decreasing in soil solution at various landscape positions due to reduced leaching. However, Ca in stream water shows slight increases, likely due to Ca released from riparian soil stores. Spatial heterogeneity is especially pronounced in headwater catchments with steep topography as evidenced by changes in solution and soil composition along hillslopes. In addition to the paper submitted for publication (Chapter 2) to Frontiers in Earth Science – Biogeochemistry this thesis includes i) a background and literature review to inform the reader on pertinent topics, ii) an appendix containing additional soil data with figures, iii) and an appendix with additional aqueous phase data with figures.

The research presented in this thesis is aimed at developing a limit state design methodology for railway track for recommendation to Standards Australia's next revision of the 'Permanent way materials: prestressed concrete sleepers' code (AS1085.14, 2003). There is widespread suspicion that the railway track, particularly concrete sleepers, have untapped reserves of strength that has potential engineering and economic advantages for track owners. Through quantifying the effects of train speed, wheel impact loadings and distribution of vehicle loads, track engineers would be able to design railway track more accurately and hence uncover the reserves of strengths in railway track. To achieve this improvement a comprehensive set of wheel/rail impact measurements has been collected over a one year period to establish a distribution of track loadings. The wheel/rail impact data collected showed a logarithmically linear distribution which shows that impact forces are randomly occurring events. The linearity of the data also allows for wheel/rail impact forces to be forecasted allowing for a more rational risk based design of the railway track. To help with an investigation of the influence of changes to train operation on the wheel/rail impact force distributions, development of a new dynamic track computer model capable of simulating the complex interaction between the train and track was completed within this research. The model known as DTRACK (Dynamic analysis of rail TRACK) was benchmarked against other dynamic models and field data to validate its outputs. The field measurements and DTRACK simulations became the basis for development of a limit state design methodology for railway track (risk based approach) for railway track in place of an allowable limit state (compliance based) approach. This new approach will allow track owners to assess the track capacity based on more realistic loads and is expected to allow an increase in the capacity of existing track infrastructure which will allow railways to be more commercially competitive and viable.

Em 2012 foi anunciado um pacote econômico do governo que concede à iniciativa privada a operação de estradas e ferrovias pelo Brasil, onde serão investidos R$ 133 bilhões, incluindo a construção de 10 mil quilômetros de estradas de ferro. O dormente é um dos componentes estruturais mais importantes na construção de ferrovias, com a função de receber esforços produzidos pelos veículos ferroviários, amortecer parcialmente as vibrações, transmiti-las ao lastro e manter invariável a distância entre os trilhos (bitola). As madeiras utilizadas no Brasil para a produção de dormentes são de essências nobres. Porém, com a escassez cada vez maior dessas espécies e a exploração ilegal de madeiras nativas consideradas de elevada resistência buscaram-se madeiras alternativas para esse uso como o Eucalipto ou o Pinus de florestas plantadas. Objetivo deste trabalho foi a análise experimental da viabilidade técnica da produção de dormentes pelo método de fabricação da Madeira Laminada Colada utilizando a madeira da espécie de Pinus oocarpa e adesivo poliuretano para atender os requisitos da recém aprovada norma de dormentes ABNT NBR 7511:2013 Dormentes de madeira - Requisitos e métodos de ensaio. Após intenso programa experimental em que foram estudadas diversas configurações de disposição de lamelas visando à otimização do processo de fabricação, foram produzidos dormentes de MLC com configurações diferentes de seção transversal, e realizados ensaios preliminares com a finalidade de atingir as especificações mínimas de norma. Os resultados mostraram que os dormentes em MLC de Pinus oocarpa atingiram os requisitos da norma ABNT NBR 7511:2013 Dormentes de madeira - Requisitos e métodos de ensaio. / In 2012 it was announced a government economic package that grants to private operation of roads and railways in Brazil, which will be invested R$ 133 billion, including the construction of 10,000 km railroads. Sleepers are one of the most important structural components in the construction of railways with the function of receiving actions produced by the rail vehicles, diminish dampen vibrations and transmitting them to the ballast and remain invariant distance between rails (gauge). The timbers used in Brazil to manufacture sleepers are from tropical forest. Considering the scarcity and tropical illegal logging, Eucalyptus and Pines planted forests are a interesting alternative. The aim of this study was experimental analyze of the technical feasibility to produce Glulam sleepers using Pinus oocarpa species and polyurethane adhesive to reach the requirements of the recently approved sleepers standard ABNT NBR 7511:2013 Wood sleepers - Requirements and test methods. After intensive experimental program using various layout settings of lamellae and different configurations of cross-sectional an optimization of the manufacturing process of MLC sleepers was done in order to achieve the minimum standard specifications. Results showed that in MLC sleepers of Pinus oocarpa reached the requirements of the standard ABNT NBR 7511:2013 Wood sleepers - Requirements and test methods.

Em 2012 foi anunciado um pacote econômico do governo que concede à iniciativa privada a operação de estradas e ferrovias pelo Brasil, onde serão investidos R$ 133 bilhões, incluindo a construção de 10 mil quilômetros de estradas de ferro. O dormente é um dos componentes estruturais mais importantes na construção de ferrovias, com a função de receber esforços produzidos pelos veículos ferroviários, amortecer parcialmente as vibrações, transmiti-las ao lastro e manter invariável a distância entre os trilhos (bitola). As madeiras utilizadas no Brasil para a produção de dormentes são de essências nobres. Porém, com a escassez cada vez maior dessas espécies e a exploração ilegal de madeiras nativas consideradas de elevada resistência buscaram-se madeiras alternativas para esse uso como o Eucalipto ou o Pinus de florestas plantadas. Objetivo deste trabalho foi a análise experimental da viabilidade técnica da produção de dormentes pelo método de fabricação da Madeira Laminada Colada utilizando a madeira da espécie de Pinus oocarpa e adesivo poliuretano para atender os requisitos da recém aprovada norma de dormentes ABNT NBR 7511:2013 Dormentes de madeira - Requisitos e métodos de ensaio. Após intenso programa experimental em que foram estudadas diversas configurações de disposição de lamelas visando à otimização do processo de fabricação, foram produzidos dormentes de MLC com configurações diferentes de seção transversal, e realizados ensaios preliminares com a finalidade de atingir as especificações mínimas de norma. Os resultados mostraram que os dormentes em MLC de Pinus oocarpa atingiram os requisitos da norma ABNT NBR 7511:2013 Dormentes de madeira - Requisitos e métodos de ensaio. / In 2012 it was announced a government economic package that grants to private operation of roads and railways in Brazil, which will be invested R$ 133 billion, including the construction of 10,000 km railroads. Sleepers are one of the most important structural components in the construction of railways with the function of receiving actions produced by the rail vehicles, diminish dampen vibrations and transmitting them to the ballast and remain invariant distance between rails (gauge). The timbers used in Brazil to manufacture sleepers are from tropical forest. Considering the scarcity and tropical illegal logging, Eucalyptus and Pines planted forests are a interesting alternative. The aim of this study was experimental analyze of the technical feasibility to produce Glulam sleepers using Pinus oocarpa species and polyurethane adhesive to reach the requirements of the recently approved sleepers standard ABNT NBR 7511:2013 Wood sleepers - Requirements and test methods. After intensive experimental program using various layout settings of lamellae and different configurations of cross-sectional an optimization of the manufacturing process of MLC sleepers was done in order to achieve the minimum standard specifications. Results showed that in MLC sleepers of Pinus oocarpa reached the requirements of the standard ABNT NBR 7511:2013 Wood sleepers - Requirements and test methods.

Dissolved organic carbon (DOC) plays an important role in the global carbon (C) cycle because increases in aqueous C potentially contribute to rising atmospheric CO2 levels. Over the past few decades, headwater streams of the northern hemisphere have shown increased amounts of DOC coinciding with decreased acid deposition. Although the issue is widely discussed in the literature, a mechanistic link between precipitation composition and stream water DOC has not yet been proposed. In this study, the breakup of soil aggregates is hypothesized as the mechanistic link between reduced acid deposition and DOC increases in surface waters. Specific hypotheses state that soil aggregate dispersion (and the ensuing release of DOC from these aggregates) is driven by a decrease in soil solution ionic strength (IS, decreasing the tendency of flocculation) as well as a shift from divalent to monovalent cations (reducing the propensity for cation bridging) in soil solution. These hypotheses were tested on soil samples collected from several riparian zone and hillslope positions along three flagged transects in the acid-impacted Sleepers River Research Watershed in northeastern Vermont. To determine soil C content by landscape position, samples from transects spanning hilltop to hillslope and riparian area, as well as replicated hillslope and riparian samples (n=40) were analyzed. Aqueous soil extracts simulate the flushing of soils during hydrologic events (e.g. rain or snowmelt) and were used to test the effect of soil solution chemistry on DOC release. Extracts were prepared with solutions of varying IS (0-0.005M) and composition (CaCl2 and NaCl) on replicated soil samples (n=54) and changes in DOC release and aggregate size were monitored. As IS of the extraction solution increased, the amount of DOC in solution decreased, and aggregate size increased. This was presumably due to cations bridging and diffuse double layer effects. This effect was reversed in low ionic strength solutions where DOC release was significantly higher and average aggregate size was smaller. While extraction solution controlled the amount of C liberated, landscape position impacted the quality, but not quantity, of released DOC. This study is the first to propose a mechanistic link observed changes in DOC in surface waters and recovery from acidification and provides initial experimental evidence that soil aggregates indeed play a role in the generation of DOC.

Within the EU's railway research program IN2TRACK3, a product known as the 3MB track system (Moulded Multi Modular Block slab track system) has been developed. The new innovative track system can be explained as a hybrid solution between traditional ballast tracks and slab track systems. The project has a primary objective for the 3MB system to reduce life cycle costs, improve reliability and punctuality, and increase capacity. The modular construction system allows for easier maintenance of railway tracks, as damaged parts can be replaced more quickly. In September 2022, a full-scale test was initiated on a 50-meter stretch in Gransjö, north of Boden, situated along the Iron Ore Line (Malmbana). Initially planned for a 2-year testing period, but the track system was dismantled and removed after approximately one year due to the emergence of a recurring severe crack pattern within the blocks. This degree project aims to conduct a thorough damage investigation, focusing on investigation the reasons behind the repeated crack patterns observed in the 3MB system. The analysis will particularly emphasise the design of the reinforcement and assesses whether the chosen concrete type is suitable for the specific conditions of the construction. Various laboratory tests, including compressive strength, tensile strength, and thin section analysis, are employed in this investigation. Additionally, a comprehensive literature study is conducted to ensure its credibility and quality. The results reveal that the aggregate in the sample is porous. This porosity increases the risk of frost damage and cracking in the concrete. The air content was measured at 7.1%, which is somewhat high, together with a high w/c equivalent between 0.50 and 0.55, which has a potentially negative impact on the strength. The study's in-depth analysis of the 3MB system blocks revealed two main problems: the choice of porous limestone as aggregate and insufficient coverage of the reinforcing steel. The porous nature of limestone led to water absorption and frost susceptibility, while inadequate coverage resulted in corrosion and frost cracking. Laboratory experiments also showed low tensile strength and uneven concrete quality. Calculations indicated the need for spalling reinforcement. Workmanship errors, including haphazard concrete pouring and suboptimal rail fastening solutions, exacerbated the situation. The study highlights the need for improvements in the concrete's waterproofing and fatigue strength to meet the system's requirements and avoid similar problems in the future. Despite the challenges, the project presents potential for success with the right adjustments and lessons learned from the initial testing phase. Despite challenges and identified obstacles in the project, the 3MB system can succeed. By fine-tuning the concrete recipe, and optimizing reinforcement and aggregate quality, the problems can be avoided. It is crucial to look beyond these obstacles and stick to the overall goal of the project: to establish the sustainable and efficient railways of the future. These challenges can be overcome through careful measures and ensure the project's positive contribution to the transport sector. / Inom EU:s järnvägsforskningsprogram IN2TRACK3 har en produkt känt som 3MB spårsystem (Moulded Multi Modular Block slab track system) utvecklats. Det nya innovativa spårsystemet kan förklaras som en hybridlösning mellan traditionella ballastbanor och ballastfria banor. Projektet har som primärt mål för 3MB-systemet att minska livscykelkostnaderna, förbättra tillförlitlighet och punktlighet, och öka kapaciteten. Det modulära byggsystemet möjliggör enklare underhåll av järnvägasspår, eftersom skadade delar kan bytas ut på ett snabbare sätt. I september 2022 inleddes ett fullskaleprov på en 50 meter lång sträcka i Gransjö, norr om Boden, belägen längs Malmbanan. Ursprungligen planerad för en 2-årig testperiod, men spårsystemet demonterades och togs bort efter cirka 1 år på grund av uppkomsten av ett återkommande allvarligt sprickmönster inom blocken. Målet med detta examensarbete är att genomföra en grundlig skadeutredning, med fokus på att undersöka orsakerna bakom de upprepade sprickmönster som observerats i 3MB-systemet. Analysen betonar särskilt dimensioneringen av armeringen och bedömning om den valda betongtypen är lämplig för konstruktionens specifika förutsättningar. Olika laboratorietester, inklusive tryckhållfasthet, draghållfasthet och tunnslipsanalys, används i undersökningen. Dessutom genomförs en omfattande litteraturstudie för att säkerställa studiens trovärdighet och kvalitet. Resultaten avslöjar att ballasten i provet är porös. Denna porositet ökar risken för frostskador och sprickbildning i betongen. Lufthalten uppmättes till 7,1%, Vilket är något högt, och tillsammans med ett högt vatten-cement-tal mellan 0,50 och 0,55, ger de en potentiellt negativ påverkan på hållfastheten. Studiens djupgående analys av 3MB-systemet block avslöjade två huvudproblem: valet av porös kalksten som aggregat och otillräcklig täckning av armeringsstålet. Kalkstenens porösa natur ledde till vattenabsorption och frostkänslighet, medan otillräcklig täckning resulterade i korrosion och frostsprickor. Laboratorieexperiment visade också på låg draghållfasthet och ojämn betongkvalitet. Beräkningar indikerade behovet av spjälkningsarmering. Utförandefel, inklusive ej fullgod betonggjutning och suboptimala rälbefästnings-lösningar, förvärrade situationen. Studien framhåller behovet av förbättringar i betongens vattentäthet och utmattninghållfasthet för att möta systemets krav och undvika liknande problem i framtiden. Trots dessa utmaningar har projektet en potential att bli framgångsrikt med rätt justeringar och lärdomar från den initiala testfasen. Trots utmaningar och identifierade hinder i projektet kan 3MB-systemet lyckas. Genom att finjustera betongreceptet, optimera armeringen och ballastkvaliteten bör uppkomna problemen undvikas. Det är avgörande att se bortom dessa hinder och hålla fast vid projektets övergripande mål: att etablera framtidens hållbara och effektiva järnvägar. Genom noggranna åtgärder kan dessa utmaningar övervinnas och säkerställa projektets positiva bidrag till transportsektorn.

A primeira ferrovia no Brasil foi inaugurada em abril de 1854 pelo Barão de Mauá com 14,5 km de extensão. Atualmente o país possui 27980 km de ferrovias e esse modal tem participação em 25% na matriz brasileira de transporte de carga. Um dos componentes mais importantes da superestrutura ferroviária é o dormente, que pode ser fabricado utilizando-se diversos materiais como a tradicional madeira, que tem uso histórico e consagrado para esta aplicação estrutural, além do concreto e do aço, e mais recentemente, os compósitos poliméricos. As madeiras com maior tradição no uso em dormentes provêm de espécies nativas de alta densidade com consequente elevada resistência mecânica e durabilidade natural. Porém, devido às restrições impostas à extração destas espécies nativas, houve forte redução de sua oferta, sendo forçada sua substituição por madeira de florestas plantadas de eucalipto de alta densidade como E. citriodora, E. paniculata e E. tereticornis. Contudo, dormentes de diferentes espécies de eucalipto, pouco adequadas para esse uso, estão apresentando muitos problemas em via. Outra madeira de florestas plantadas muito utilizada no Brasil é o pinus e uma aplicação muito nobre para este tipo de madeira é a produção de elementos estruturais em Madeira Lamelada Colada (MLC). O objetivo do presente trabalho foi o estudo teórico e experimental de dormentes de MLC confeccionados com madeiras de Pinus spp. tratadas com CCA, coladas com adesivo poliuretano, e reforçados com tecido bidirecional de fibra de vidro. Para tanto, realizou-se um estudo teórico e experimental a partir de ensaios estáticos e dinâmicos tendo-se em vista a necessidade de utilização de novas espécies de madeira de reflorestamento com resistência adequada a tal finalidade. Os resultados obtidos nos ensaios realizados de acordo com a normalização vigente atestaram a viabilidade técnica da utilização de dormentes em MLC de Pinus spp. reforçados com fibra de vidro desde que sejam realizadas as classificações visual e mecânica das lamelas, para a obtenção das propriedades de resistência e rigidez necessárias. / Brazil\'s first railroad was inaugurated in April, 1854 by Barão de Mauá with 14.5 km of extension. Currently the country has 27980 km of railways, and this transportation modal has 25% participation in the Brazilian freight transport matrix. One of the most important elements of railway superstructure is the sleeper (or tie), which can be manufactured from several materials, such as the traditional wood, that has historical and well-established use for this structural application, as well as concrete, steel, and recently, polymer composites. The classic sleeper is made by timber from native species of high density with consequent high mechanical strength and natural durability. However, due to the restrictions imposed on the extraction of these native species, there was a strong reduction in their supply, being forced to replace them with timber from high density eucalyptus planted forests such as E. citriodora, E. paniculata and E. tereticornis. Therefore, sleepers from different eucalyptus species, that are not suitable for this use, are presenting many problems on railroad. Another wood from planted forests widely used in Brazil is the pinus, and a very noble application for this kind of wood is the production of structural elements in Glued Laminated Timber (Glulam). The aim of this work was the theoretical and experimental study based on static and dynamic tests of Glulam sleepers manufactured using Pinus spp. treated with CCA, glued with polyurethane adhesive, and reinforced with bidirectional fiberglass fabric. For that, a theoretical and experimental study was carried out from static and dynamic tests, considering the potential use of new reforestation species of wood with suitable strength to this purpose. The results show technical feasibility in the use of Glulam sleepers made with Pinus spp. reinforced with fiberglass provided that visual and mechanical classifications of the timber are realized, in order to obtain the required strength and stiffness properties.