Publicações

The ballast mechanical behavior is one of most important aspects governing the performance and safety conditionsof railway track lines. Usually comprised of natural crushed rock, the research for alternative ballastmaterials becomes interesting both environmentally and economically. This paper presents a comparison betweenaggregates of steel slag and granite by means of monotonic and cyclic triaxial tests carried out on scaleddown ballast specimens. The monotonic triaxial tests were conducted at three different confining pressures tofailure and to critical state. The long-term cyclic tests (at least 106 cycles) were conducted in two stress pathscompatible with heavy haul loadings. The results showed that the steel slag aggregate has higher values ofstrength parameters compared to the granite aggregate and better long-term deformability behavior, expressedby lower degradation and particle breakage and a faster tendency for stabilization the permanent deformation.

The ballast railway layer is one of the main applications of crushed rocks in civil engineering. Environmentalconcerns have influenced the use of by-products and recycled materials as alternatives to the exploitation of new quarries. One of the main industrial by-products available near railways is steel furnace slag. Mechanical tests performed by monotonic and cyclic triaxial loading showed that this material can perform better than a granite aggregate traditionally used in the ballast layer. The work presented in this paper intends to be a contribution explaining the influence of the individual particles

Railway infrastructure managers run dedicated inspection vehicles to monitor the geometric quality of the track (among other aspects) to detect irregularities and ensure safe running conditions of railway lines, in accordance with specific regulations. Unfortunately, these inspections disturb the normal traffic operation, especially in networks with intense traffic; are generally carried out only a few times per year; and, consequently, do not provide prompt identification of critical situations. Considering the recent developments and cost reduction in sensing capabilities of smartphones, the authors present an approach to use these technologies to perform constant acceleration measurements inside in-service trains to complement the assessment of the structural performance and geometrical degradation of the tracks. Cross-correlation values above 0.85 were obtained between the standard deviations of the longitudinal level and the experimental vertical accelerations measured on-board a passenger train on an 11-km railway stretch. ,e results showed that the approach can be used to identify critical situations that affect the performance of the track, regarding passenger comfort, degradation rates, and risk of derailment. It may comprise a low-cost and crowdsourced complement to the general current practice of track geometric inspection by dedicated vehicles and contribute to an earlier detection of track malfunctions, consequently, to a more efficient maintenance planning and infrastructure management.

The selection and use of technical parameters and performance indicators plays an essential role in thepavement management process. It is known that if more parameters are used, a more accurate evaluationof pavement condition is achieved, improving the choice of maintenance and rehabilitation interventions.However, one of the most expensive activities of the pavement management process is data collection.Accordingly, it is necessary to find a balance between the data collected and the real needs of the process.This paper presents a new approach for the development of pavement condition indicators using a machinelearning algorithm named regularised regression with lasso. The present discussion is supported by a casestudy, which compares the proposed method with current practice for the description of the condition of aPortuguese motorway. The results suggest that the application of machine learning methods can improvethe accuracy of pavement condition indicators when less data are available, contributing to achieve abalance between the needed data and information obtained.

Transition zones to bridges and other structures are critical locations in railway tracks that frequently evidencepoor long-term performance. Under sleeper pads (USPs) are reported to reduce ballast degradation and controlthe vertical stiffness of the track, which suggests that USPs can contribute to mitigating the frequent negativeeffects associated with transitions zones. Aiming at understanding in greater depth the influence of USPs on thedynamic behaviour of transition zones and at improving the design of such railway structures, the authors havedeveloped an extensive experimental and numerical study. 3-D FEM models using state-of-the-art numericalapproaches were successfully calibrated and validated using experimental measurements. Simulations supportedprevious findings, highlighting the potential benefit of USPs and pointing to the need to careful designing of theresilient properties of USPs and their arrangement along transition zones, so as to avoid introducing abruptvariations in track vertical stiffness.

Ballast aggregate is a natural material widely used in railway lines. Its mechanical properties and particle geometry are meticulously defined using well-established standards and characterisation procedures. Though extensively validated, these procedures have some limitations: they are operator dependent; only provide major particle dimensions; do not inform on surface colour; nor allow for advanced particle wear analysis or particle-based simulations. This work presents a cost-efficient photogrammetry method for 3D reconstruction of ballast particles, as an alternative to the significantly expensive laser scanning. It produces digital models of equivalent or higher quality, allowing for advanced and automated particle geometry analyses. Particle meshes produced here are shared among researchers.

The railway track system is a crucial infrastructure for the transportation of people and goods in modern societies. With the increase in railway traffic, the availability of the track for monitoring and maintenance purposes is becoming significantly reduced. Therefore, continuous non-destructive monitoring tools for track diagnoses take on even greater importance. In this context, Ground Penetrating Radar (GPR) technique results yield valuable information on track condition, mainly in the identification of the degradation of its physical and mechanical characteristics caused by subsurface malfunctions. Nevertheless, the application of GPR to assess the ballast condition is a challenging task because the material electromagnetic properties are sensitive to both the ballast grading and water content. This work presents a novel approach, fast and practical for surveying and analysing long sections of transport infrastructure, based mainly on expedite frequency domain analysis of the GPR signal. Examples are presented with the identification of track events, ballast interventions and potential locations of malfunctions. The approach, developed to identify changes in the track infrastructure, allows for a user-friendly visualisation of the track condition, even for GPR non-professionals such as railways engineers, and may further be used to correlate with track geometric parameters. It aims to automatically detect sudden variations in the GPR signals, obtained with successive surveys over long stretches of railway lines, thus providing valuable information in asset management activities of infrastructure managers.

The authors present a numerical study on railway track subgrade reinforcement using short soil-binder columns through injection, below the ballast layer. A 3D FEM program developed in MATLAB that considers the dynamic train

Sudden changes in the structural and geotechnical properties of railway tracks along its course are normally associated with subgrade stiffness transitions, differential settlements and, ultimately, hanging sleepers that reduce the performance of the railway system. This paper aims at analysing and quantifying the impact of such situations, particularly cut-fill transitions combined with the presence of culverts, on the train-track system response. A cut-fill transition on a buried culvert is used as case study for which track geometry and stiffness evaluation data were available. A numerical model, considering the coupled train-track interaction, was developed using a 3D FEM dynamic analysis tool that was further improved here with a mixed implicit-explicit time integration scheme. The results suggest that the faster degradation rates typically found at similar locations are mostly related to the development of early permanent deformations in the subgrade layers, rather than to sudden stiffness transitions, which then aggravate the problem by causing important dynamic amplifications in the train-track interaction. Therefore, numerical approaches similar to the one presented herein can be valuable tools for designers and railway infrastructure managers in order to anticipate and mitigate such negative effects at these locations.

Soil improvement with hydraulic binders is currently used in practice because of the advantages of using the local soil enhancing its geotechnical properties. However, environmental issues related to quicklime applications and carbon-dioxide emissions associated to Portland cement production encouraged the development of new binders. In this work, alkaline-activated cement (AAC) synthetized by fly ash and an alkaline solution was used to stabilize silty sand. The behavior of the treated soil was evaluated performing tests on a physical model and the results were compared to laboratory data to define its compaction, strength, and stiffness properties. Those tests include nuclear density gauge measurements, light falling weight deflectometer tests, and plate load tests, whereas unconfined compression tests with unload

No âmbito de um estudo realizado no Laboratório Nacional de Engenharia Civil sobre a caracterização de fileres para a utilização em infraestruturas de transporte, pretendeu-se determinar quais as propriedadesfisicas, geométricas e mecânicas daqueles materiais que mais influenciam o comportamento das misturas betuminosas. Neste estudo foram ainda introduzidos materiais alternativos ao filer comercial, dado o interesse verificado ao longo dos ültimos anos de aumentar a reutilização de subprodutos industriais e de RCD, eventualmente após um processo de valorização. Assim, no presente trabalho para além da descrição do objetivo do estudo, âmbito e metodologia, são apresentados os resultados laboratoriais dacaracterização de nove fileres de diferentes origens. Após a caracterização dos fileres fol possivel identificar algumas relaçôes entre as propriedades fisicas, geométricas e mecânicas dos materials, além da avaliação da viabilidade de aplicação dos materiais alternativos como substitutos do filer comercial.

As descontinuidades dos maciços rochosos influenciam o seu comportamento mecânico e hidráulico e consequentemente as obras neles construídas. Este trabalho descreve o desenvolvimento e aplicação de uma técnica de digitalização das superfícies de descontinuidades rochosas que recorre a uma mesa digitalizadora, visando contribuir para a compreensão dos mecanismos de contacto e desgaste. As superfícies numéricas obtidas são analisadas usando parâmetros geo-estatísticos que podem ser comparados com outros semi-empíricos, como o JRC, permitindo quantificar a evolução da rugosidade após ensaios mecânicos de compressão ou deslizamento. Os resultados deste trabalho permitiram geração de descontinuidades sintéticas que poderão ser usadas futuramente em modelos micromecânicos de partículas para simular o comportamento mecânico e hidráulico de descontinuidades.

This paper describes the measurement and analysis of the roughness of natural rock joints with the aim of proceeding to their characterisation and comparison. Eight rock joints (corresponding to sixteen surfaces) were scanned with a three-dimensional scanner. This was followed by the description and characterisation of the surface roughness, as well as its reproduction and generation using techniques such as fractal models and Fourier transforms. Shear tests under constant normal load were performed, the joint surfaces were again scanned, and the resulting roughness surfaces were compared allowing the evaluation of asperity breakage and surface wear. One of the joint specimens was tested under several normal stresses, which allowed the estimation of its mechanical characteristics, and was scanned after each test to evaluate the influence of the normal and shear load on the variation of roughness. The scans of the rock joints produced accurate numerical descriptions of their topologies, allowing countless possibilities of future studies, such as the study of the matching of rock joints by the numerical adjustment of bottom and top surfaces, the statistical and geostatistical characterisation of rock joints or the degradation of roughness after normal and shear tests. This paper presents an overview of the research work that is still under way.

In order to evaluate the level of ballast fouling for Portugal aggregates and the influence of antenna frequency on its measurement several laboratory tests were performed on different materials. Initially the clean granitic ballast was tested in different water content conditions, from dry to soak in order to see the influence of water on the dielectric characteristics. The fouling of the ballast was reproduced in laboratory through mixing the ballast with soil, mainly fine particles, in order to simulate the fouling existing in several old lines in Portugal, where the ballast was placed over the soil without any sub ballast layer. Five different fouling levels were reproduced and tested in laboratory, with different water contents, four for each fouling level. Tests were performed with five Ground Penetrating Radar (GPR) antennas with different frequencies, three ground coupled antennas of 400 MHz, 500 MHz and 900 MHz, and two horn antennas of 1000 MHz and 1800 MHz. In situ test pits were than used to validate the values of the dielectric constants obtained in laboratory. The main results obtained are presented in this paper together with troubleshooting associated to measurement on fouling ballast. This study is of interest for COST Action TV 1208.

O desempenho das vias-férreas é fortemente influenciado pelo comportamento da sua subestrutura. As características intrínsecas e de estado dos geomateriais e a existência de singularidades, as quais se traduzem por uma variação brusca de rigidez das camadas de apoio da via e, em alguns casos, conduzem a assentamentos diferenciais importantes, influenciam a qualidade geométrica, medida ao nível dos carris. O presente trabalho analisa a influência da rigidez das camadas e da existência de singularidades na evolução da qualidade geométrica da via. Para tal, apresentam-se resultados da caracterização realizada durante a construção e da monitorização na fase de operação de um trecho de via-férrea construído no âmbito da modernização de uma linha, em Portugal. Analisa-se a variação da rigidez das camadas e do nivelamento longitudinal dos carris, no tempo e ao longo da via. Conclui-se que a existência de singularidades ao nível da subestrutura da via influencia a qualidade geométrica e a sua evolução. Apesar de os aterros de transição, construídos entre as terraplenagens e as obras de arte e sobre as estruturas enterradas, promoverem uma transição de rigidez relativamente mais gradual do que a que existiria na sua ausência, ainda assim, essa singularidade reflete-se na qualidade geométrica da via e na sua evolução ao longo do tempo. Em face dos resultados obtidos, propõe-se que a análise da degradação das zonas de transição se faça utilizando critérios distintos dos habitualmente utilizados.

The stress dependent behaviour of the unbound granular materials that carry the track,and the voids that may occur between the base of the sleepers and the ballast, arethe important factors for non-linear track behaviour. On transition zones, where thetrack stiffness may rapidly vary and often differential settlements take place betweenthe stiff structure and the approach section of the track, these aspects are of particularrelevance. Despite the non-linear constitutive behaviour of unbound aggregates, it isstill common practice to consider the linear elastic behaviour for these materials inthe design of transportation infrastructure. The present study focuses on the imple-mentation of these non-linear aspects in a

A construção de vias-férreas implica obras de grande envergadura que envolvem custos muito elevados, pelo que a reabilitação das mesmas é uma opção frequente quando se pretende evoluir para maiores velocidades de circulação, maior carga por eixo ou melhorar as condições de operação. A caracterização geológica e geotécnica da infraestrutura nesse contexto, envolve problemas complexos associados aos habitualmente curtos intervalos de tempo de interdição de via, que limitam significativamente a frequência de recolha de informação e a variedade de ensaios elegíveis. De facto, este contexto condiciona fortemente a utilização de meios de prospecção mais correntes neste tipo de trabalhos, nomeadamente a realização de sondagens mecânicas e a execução de ensaios de carga com placa. Neste artigo apresenta se uma metodologia para avaliação das condições geomecânicas da via-férrea em fase de operação, baseada em dois modelos aplicados pela MOTA-ENGIL na secção 5 do corredor de Nacala (Malawi) e na Linha de Sena (Moçambique). Estes modelos revelaram-se eficientes tanto sob o ponto de vista de obtenção das características geométricas da estrutura e informação geomecânica, como na quantidade de pontos amostrados e tempos de execução dos trabalhos de campo.

A construção de vias-férreas implica obras de grande envergadura que envolvem custos muitoelevados, pelo que a reabilitação das mesmas é uma opção frequente quando se pretende evoluir para maiores velocidades de circulação, maior carga por eixo ou melhorar as condições de operação. A caracterização geológica e geotécnica da infraestrutura nesse contexto, envolve problemas complexos associados aos habitualmente curtos intervalos de tempo de interdição de via, que limitam significativamente a frequência de recolha de informação e a variedade de ensaios elegíveis. De facto, este contexto condiciona fortemente a utilização de meios de prospecção mais correntes neste tipo de trabalhos, nomeadamente a realização de sondagens mecânicas e a execução de ensaios de carga com placa. Neste artigo apresenta-se uma metodologia para avaliação das condições geomecânicas da via-férrea em fase de operação, baseada em dois modelos aplicados pela MOTA-ENGIL na secção 5 do corredor de Nacala (Malawi) e na Linha de Sena (Moçambique). Estes modelos revelaram-se eficientes tanto sob o ponto de vista de obtenção das características geométricas da estrutura e informação geomecânica, como na quantidade de pontos amostrados e tempos de execução dos trabalhos de campo.

Vibrations in rockmasses can be a significant hazard, leading to human discomfort and structural damage. Recent cases of subway or tunnel excavation near existing dams in Portugal have raised again theimportance of this topic. Traditional statistical tools have been used to study wave propagation in rock, but fall short when rock fracturing or faulting radically changes the way vibration propagates. Numerical models such as finite-element or finite-difference models also have some insufficiencies, namely in the way discontinuities are represented.We propose the utilization of bonded particlemodels based on the ParticleDiscrete ElementMethod. Synthetic rock samples are generated and their static elastic properties are calibrated by manipulating micro- properties (assembly organization and normal and shear contact stiffness). The static and dynamic properties of the rock cores are tested and the complete elastic response of the model is evaluated and discussed.

Vibrations in rockmasses can be a significant hazard, leading to human discomfort and structuraldamage. Recent cases of subway or tunnel excavation near existing dams in Portugal have raised again theimportance of this topic. Traditional statistical tools have been used to study wave propagation in rock, but fallshort when rock fracturing or faulting radically changes the way vibration propagates. Numerical models such asfinite-element or finite-difference models also have some insufficiencies, namely in the way discontinuities arerepresented.We propose the utilization of bonded particlemodels based on the ParticleDiscrete ElementMethod.Synthetic rock samples are generated and their static elastic properties are calibrated by manipulating micro-properties (assembly organization and normal and shear contact stiffness). The static and dynamic properties ofthe rock cores are tested and the complete elastic response of the model is evaluated and discussed.

This case study refers to the first significant experience with asphalt rubber, manufactured by the wetprocess, applied on a full scale rehabilitation project in Portugal. It concerns the application of a gapgradedasphalt rubber wearing course in the rehabilitation of the pavement of National road stretchesEN 104 between Azurara and Trofa and EN 105 between Travagem and Santo Tirso. / O presente caso de estudo refere-se à primeira experiência relevante, em Portugal, na qual seutilizaram misturas com betume modificado com borracha reciclada de pneus na reabilitação deestradas nacionais. Diz respeito, em particular, à aplicação de misturas betuminosas rugosas combetume modificado com borracha em camadas de desgaste, no âmbito da reabilitação do pavimento deum troço da estrada nacional EN 104, entre Azurara e Trofa, e da estrada nacional EN 105, entreTravagem e Santo Tirso.

This case study refers to a successful application of an asphalt rubber wearing course in the frame ofthe rehabilitation of the pavement of the National Road EN 14 between

This case study refers to plant hot mix recycling works in the frame of the rehabilitation of a stretch ofthe motorway A1, located in the centre of Portugal.It concerns the use of 20% - 25% of Reclaimed Asphalt in the production of two different asphaltconcrete mixtures for application in binder courses. / O presente caso de estudo refere-se ao fabrico e aplicação de misturas betuminosas recicladas a quenteem central, num troço da auto-estrada A1 localizado no centro do País. Neste caso, foram utilizadas nofabrico de duas misturas diferentes, uma Mistura Betuminosa Densa e um Betão BetuminosoSubjacente à Camada Drenante, respectivamente, cerca de 20 % e 25 % de misturas betuminosasrecuperadas.

This case study refers to the first known application of RAP in the production of hot mix asphaltconcrete in Portugal. It concerns the application of a plant hot mix recycled asphalt concrete as abinder course in a national road stretch located in the North of Portugal. / O presente caso de estudo refere-se à primeira obra realizada em Portugal, na qual se procedeu àreutilização de materiais betuminosos fresados na reabilitação de um pavimento flexível de um trechode uma estrada nacional (EN105), situada no Norte do País. Os materiais fresados foram reciclados emcentral mediante a incorporação de novos materiais, e posteriormente utilizados em camadas deregularização.

This case study refers to an application of cold in situ recycling of an old asphalt pavement usingbitumen emulsion.The rehabilitation works were performed in 2 phases: The first phase consisted in recycling theexisting asphalt and granular layers up to 120 mm deep and application of a slurry surfacing. Thesecond phase consisted in placing an asphalt cold mix binder course and a new slurry surfacing. / O presente caso de estudo refere-se à aplicação de misturas betuminosas recicladas a frio

This case study refers to a successful application of cold in situ recycling of asphalt layers from aheavily cracked pavement using bitumen emulsion.A new hot mix asphalt binder course and a new wearing course were placed on the recycled layer. / O presente caso de estudo refere-se a uma aplicação bem sucedida de reciclagem a frio

The use of alternative materials, in particular industrial by-products and waste materials, in the construction oftransport infrastructures and geotechnical works, has been promoted across the world. Nonetheless, considering that, in most situations, the application of some of these materials is fairly recent, little information is available on the long-term performance of the infrastructures in which they were used. This work mentions some characteristics of the Inert Steel Aggregate for Construction (ISAC). It presents some results related to the evolution in the surface characteristics and the structural behaviour of a field trial built on a road section in Portugal. ISAC was used in the embankments and pavement layers. The visual inspection, the results of the mechanical tests performed, and the values of the settlements measured on the surface markings about ten years after the section is open to traffic led to conclude that the pavement in the zone where ISAC was used as a construction material is, in general, in a better condition and presents better structural performance than the adjacent areas built with natural materials. The embankment's maximum settlements in the areas with ISAC were similar to the ones observed in the adjacent areas.

Railway tracks may be perceived as simple physical structures, but in fact they entail a significant level of complexity as refers to the assessment and prediction of their transient and long-term behaviors. These mostly result from the intrinsic characteristics of their components and of the dynamic interaction with the suc-cessive passing trains at different speeds and with different loading characteris-tics. The railway industry

A via férrea balastrada é uma estrutura relativamente simples, mas exibe um comportamento complexo, nomeadamente devido às distintas solicitações dinâmicas a que está sujeita, e à forma como se comportam e interagem os seus diversos elementos. O método dos elementos finitos é particularmente adequado à análise do funcionamento destas estruturas, possibilitando a modelação das ações e a utilização de modelos constitutivos avançados para os diversos materiais que constituem o sistema, permitindo considerar a variação das características físicas e geométricas no espaço. Neste capítulo descreve-se e demonstra-se a aplicação de uma ferramenta de modelação numérica tridimensional, concebida especificamente para o cálculo da resposta dinâmica da via-férrea, cujo desenvolvimento, ao longo dos últimos anos, tem tido a contribuição dos autores. Para além da apresentação e validação da ferramenta de modelação, são apresentados estudos relativos à análise do comportamento da via em situações particulares.

A utilização de machine learning tem despertado a curiosidade e o interesse do meio académico e empresarial. Com efeito, a aplicação de machine learning, baseada em técnicas capazes de aprender com os dados, tem sido efetuada com sucesso em diversos contextos. Este sucesso é particularmente evidente nas áreas que utilizam grandes volumes de dados e que procuram obter informação que permita alimentar modelos de previsão.Na área dos Transportes, para além da resolução de questões relacionadas com a mobilidade, é expectável que a aplicação de técnicas de machine learning venha a ser cada vez mais frequente em questões relacionadas com a gestão de infraestruturas, em particular no estabelecimento de modelos de previsão do comportamento.Neste capítulo procura-se evidenciar o potencial da aplicação de machine learning em sistemas de gestão de pavimentos, através da descrição de alguns dos trabalhos desenvolvidos pelos autores neste domínio, essencialmente relacionados com a aplicação de machine learning no desenvolvimento de modelos de previsão do desempenho dos pavimentos, uma das temáticas essenciais dos sistemas de gestão de pavimentos.

Este artigo apresenta uma etapa de uma pesquisa mais abrangente que está em andamento na Universidade do Porto, no âmbito do grupo de pesquisa Construct-Geo, que visa avaliar os aspectos geomecânicos de materiais alternativos para uso como camada de lastro em vias férreas do tipo heavy haul. São apresentados resultados de ensaios triaxiais monotônicos e cíclicos conduzidos em corpos de prova de 150 mm de diâmetro por 300 mm de altura, em escala reduzida numa proporção de 1:2,5 em relação à granulometriade lastro padrão AREMA N. 24. Analisou-se um agregado de escória de aciaria, quimicamente e ambientalmente, inerte comparativamente a um agregado de granito, relativamente à resistência e à deformabilidade. Os ensaios cíclicos foram conduzidos em dois escalões de carga de 500.000 ciclos, sendo cada escalão compatível com o carregamento imposto por vias do tipo heavy haul com, respectivamente,32,5 toneladas/eixo e 40 toneladas/eixo. Os resultados mostraram que o lastro de escória de aciaria apresentou parâmetros de resistência superiores comparativamente ao lastro de granito e um melhor comportamento quanto à deformabilidade, expresso por maiores valores de módulo de resiliência, menoresíndices de quebra e degradação de partículas e uma maior tendência de estabilização das deformações plásticas, fenômeno conhecido como shakedown e que também foi investigado.

The reuse of recycled materials in geotechnical works has awakened a growing interest in the last few years in Portugal. A committee (GT-VROG) within the Portuguese Geotechnical Society (SPG) was created recently for analysing the current state of this kind of use and for promoting it nationwide. As part of the activities of the group, a national survey within producers of waste materials and potential users in geotechnical works was carried out, and a national seminar was organised within the framework of the activities of the TC-3 of the ISSMGE, in order to discuss the present situation in the country and the best ways to develop the reuse of this kind of materials in geotechnical applications. The seminar had the participation of representatives of the different entities interested on the subject (producers, users, administration and research centres), as well as of invited foreign specialists from other European countries. Taking advantage of the results of these activities, the current state of the use of recycled materials in geotechnical works in Portugal is briefly presented and analysed next.

Transportation infrastructures are vital to our society. These infrastructures naturally tend to deteriorate over time. A set of activities is then required to manage existing assets in accordance with sound management principles. These activities are usually integrated into systems that manage infrastructures according to technical, social and economic aspects. This research aims to examine the potential of applying machine learning techniques to current transportation infrastructure management systems. Machine learning is an application of artificial intelligence enabling systems to automatically learn and improve from experience (data), arriving at solutions not explicitly programmed. Powered by algorithms that can learn from data, machine learning leads to efficient and effective systems that improve over time. Over the last few years, the application of machine learning has transformed several industries and could do so for transportation infrastructure as well.To achieve the research objectives, a set of studies was performed. Each of these studies had a specific objective, the set of which can be expressed as follows: to define combined performance indicators for pavement condition assessment using machine learning; to develop machine learning models for pavement performance prediction; to formulate machine learning solutions to overcome pavement data issues, such as missing data; to integrate machine learning techniques into decision support systems for pavement maintenance management. Together these studies explored the development of machine learning applications for solving some standard pavement management problems, providing insights into the application of machine learning to transportation infrastructure management systems. The studies successfully demonstrated the potential of machine learning applications for pavement management systems. It showed that machine learning is applicable to various transportation asset management problems, such as condition assessment, performance prediction, and decision support, and that it is able to outperform some of the analytical techniques currently used. Overall, this research work finds that machine learning is a promising tool for transportation infrastructure management systems.

The railway track continually degrades over its life cycle. This has negative consequences for maintenance and availability of the lines and is particularly evident at locations with abrupt changes in the track

Esta dissertação pretende ser um contributo para o desenvolvimento de uma metodologia de abordagem do problema da renovação de plataformas ferroviárias em serviço, em particular no que se refere à avaliação da capacidade de carga e técnicas de reforço. A referida metodologia foi desenvolvida com o objectivo de apoiar os projectos de renovação das vias férreas.Os principais aspectos abordados são os mecanismos que contribuem para a degradação das vias férreas, a caracterização

Nas últimas décadas tem vindo a verificar-se, em Portugal bem como no resto do mundo, umacentuado crescimento do volume de tráfego rodoviário e das cargas transportadas pelos veículospesados. Tem-se observado, igualmente, um aumento das exigências funcionais, relacionadas com asegurança e conforto do utente das infra-estruturas, a par das preocupações de carácter ambiental, oque conduz à necessidade de pavimentos rodoviários cada vez mais resistentes e duráveis.Consequentemente, tem-se vindo a recorrer a soluções de pavimentação que envolvem maioresespessuras de camadas betuminosas o que implica uma maior parcela de contribuição docomportamento deste tipo de materiais no desempenho das estruturas de pavimentos. Daqui decorre,entre outros aspectos, uma crescente preocupação com a deformação permanente deste tipo demateriais. Esta situação é também sentida em diversos países, nomeadamente nos países europeus,no Canadá e nos Estados Unidos da América.O presente trabalho tem como objectivo contribuir para um melhor conhecimento do comportamentoà deformação permanente de misturas betuminosas aplicadas em camadas de desgaste depavimentos rodoviários, possibilitando o estabelecimento de metodologias e de critérios de avaliação,que conduzam à selecção de materiais adequados às exigências actuais. Como principais aspectosabordados referem-se a caracterização do comportamento viscoelástico destes materiais, através daexecução e interpretação de ensaios laboratoriais com aplicação de cargas repetidas, que simulemas condições observadas in situ, e a modelação do comportamento à deformação permanente dasmisturas.É analisado o fenómeno da deformação permanente, bem como a sua forma de manifestação naestrutura do pavimento

No âmbito Programa de Investigação e Inovação do LNEC 2013-2020 (P2I) e inserido no Programa de ID&I do Departamento de Transportes (DT), o Núcleo de Infraestruturas de Transportes tem vindo a desenvolver um projeto de ID&I designado por

Executive SummaryInfrastructure is the backbone of our society. Citizens, companies and governments have come to rely on and expect uninterrupted availability of the road network. Climate change is an important topic within the context of designing, maintaining and operating traffic networks. Most transport infrastructure is intended to be available (in service) to the public for several decades. The life cycles of assets in transport are long enough to take the full strain that comes with climate change; however, climate impact is experienced on a small scale. Crops are destroyed by floods, timber is felled by heavy storms and infrastructure is devastated by various kinds of extreme events. The adaptation of road networks to a changing climate is one of the important issues that road authorities have begun to address and that needs to be further continued in the near future.The main objective of the Conference of European Directors of Roads (CEDR) Call 2012

The Mozambican Roads Administration (ANE) has embarked on a project to establish a Road Research Centre (RRC) in Mozambique aiming to provide the basis for improving the long-term capacity to undertake relevant, high quality research relating to the road sector of Mozambique. This project forms part of the Africa Community Access Programme (AFCAP), which is a research programme supported by the Department of International Development (DFID) of the Government of the United Kingdom and managed by Crown Agents Ltd on behalf of DFID. CSIR, in association with LNEC has been commissioned by Crown Agents to provide Technical Assistance for phase 2 A of the project, which aims to address institutional issues relating to the RRC, draft a strategic research plan and develop a 5-year business plan for the RRC. This monthly progress report dated January 2014 summarises progress made with the identification of the road research needs of Mozambique; the production of recommendations on the institutional structure of the RRC; the establishment of the Road Research Technical Committee (RRTC) and the Road Research Steering Committee (RRSC); and the drafting of the business and strategic research plans for the RRC. The activities planned for February 2014 are also presented.

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The Mozambican Roads Administration (ANE) has embarked on a project to establish a Road ResearchCentre (RRC) in Mozambique aiming to provide the basis for improving the long-term capacity toundertake relevant, high quality research relating to the road sector of Mozambique. This project formspart of the Africa Community Access Programme (AFCAP), which is a research programme supported bythe Department of International Development (DFID) of the Government of the United Kingdom andmanaged by Crown Agents Ltd on behalf of DFID. CSIR, in association with LNEC has been commissionedby Crown Agents to provide Technical Assistance for phase 2 A of the project, which aims to addressinstitutional issues relating to the RRC, draft a strategic research plan and develop a 5-year businessplan for the RRC. In this report, appropriate institutional structures for undertaking research arepresented. It addresses the following: (i) the Terms of Reference for a functioning Road ResearchSteering Committee (RRSC) and Road Research Technical Committee (RRTC), as well as an overview ofthe outcomes of the inaugural meetings of both of these committees; (ii) the institutional location ofthe RRC within the structures of ANE; (iii) the physical location of the RRC in Mozambique; (iv)laboratory support for a functioning RRC; and (v) Staffing of the RRC. All items, with the exception of thelast item (

No âmbito do Convénio de Cooperação entre o Laboratório Nacional de Engenharia Civil(LNEC) e o Programa de Capacitação dos Laboratórios de Engenharia dos PALOP eAdministração Pública de Timor-Leste 2013, realizou-se no Laboratório de Engenharia Civilde São Tomé e Príncipe (LECSTP) um curso subordinado ao tema

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As crescentes exigências impostas ao transporte ferroviário e a necessidade de o tornar num sistemade transporte mais competitivo, têm levado ao desenvolvimento de novas soluções de via-férrea.Estas novas soluções constituem inovações tecnológicas de via-férrea que diferem da via balastradatradicional na utilização de diferentes materiais e métodos construtivos. Apostam fortemente naredução da necessidade de conservação e renovação da via, o que se traduz na diminuição doscustos associados à sua operação, assim como no aumento da disponibilidade da linha.Assim, estas soluções apresentam uma melhor resposta a velocidades de circulação cada vez maiselevadas e a maiores volumes de tráfego, que tendem a conduzir a maior deterioração da via e aconsequentes maiores custos de conservação e renovação. Em comparação com a via tradicional,estas soluções podem ser mais vantajosas, no que se refere à segurança, a aspectos ambientais, àgestão da operação e a custos globais, quando se considera o ciclo de vida da infra-estrutura.Embora estas tecnologias tenham vindo a ser testadas e aplicadas em alguns países, desde há váriasdécadas, em particular no Japão, só mais recentemente diversos países demonstraram especialinteresse pela sua aplicação. Face a estas vantagens, tem-se verificado actualmente uma crescentetendência para a adopção destas novas soluções, sobretudo para as linhas de alta velocidade,particularmente na Europa e Ásia Oriental.Dentro deste contexto, e tendo em conta a previsível integração de Portugal na Rede Europeia de AltaVelocidade, desenvolveu-se o presente estudo com o objectivo de apresentar diversas soluções devia-férrea que estão disponíveis e compará-las com a solução tradicional de via balastrada.O estudo incide na descrição de concepções de via-férrea não tradicionais, como a via sem balastro ea via de apoio misto, fazendo-se especial referência às principais vantagens e desvantagens da viasem balastro, face à solução tradicional de via balastrada, e à experiência da sua aplicação.Apresenta-se ainda uma síntese da situação actual da aplicação destas novas soluções em paísesque apostaram fortemente nas redes de alta velocidade.Do estudo desenvolvido conclui-se que, para novas linhas de alta velocidade, estas soluções podemser bastante atractivas, como alternativa à via balastrada tradicional.Os autores agradecem a todas as entidades e pessoas a título individual a autorização expressa paraa publicação das ilustrações apresentadas neste estudo, encontrando-se estas devidamentereferenciadas.

The reuse of recycled materials in geotechnical works has awakened a growing interest in the last few years in Portugal. A committee (GT-VROG) within the Portuguese Geotechnical Society (SPG) was created recently for analysing the current state of this kind of use and for promoting it nationwide. As part of the activities of the group, a national survey within producers of waste materials and potential users in geotechnical works was carried out, and a national seminar was organised within the framework of the activities of the TC-3 of theISSMGE, in order to discuss the present situation in the country and the best ways to develop the reuse of this kind of materials in geotechnical applications. The seminar had the participation of representatives of the different entities interested on the subject (producers, users, administration and research centres), as well as of invited foreign specialists from other European countries. Taking advantage of the results of these activities, the current state of the use of recycled materials in geotechnical works in Portugal is presented and analysed next.

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