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Prepared Project: Deliverable 4.3.4 On-line monitoring of CSO: sewer and receiving waters
No full textEste registo pertence ao Repositório Científico do LNEC13pDHA/NE
RADE – 8th Experience on Remote Access - 16th December 2013
No full textEste registo pertence ao Repositório Científico do LNEC13327pDHA/NP
E2I - Estratégia de investigação e inovação 2013-2020
No full textEste registo pertence ao Repositório Científico do LNECNÃO CONFIDENCIALC
Relatorio dos trabalhos do projeto de investigação
No full textEste registo pertence ao Repositório Científico do LNECOs impactos dos derrames acidentais das últimas décadas têm impulsionado o desenvolvimento e a implementação de diversas abordagens para planeamento e resposta à emergência de poluição dos meios aquáticos, incluindo sistemas de monotorização da poluição e sistemas de modelação. Os sistemas de gestão d risco, que foram aplicados com sucesso para tsunamis e inundações de rotura de barragens, podem ser usados para providenciar um enquadramento para riscos de poluição que permita a proteção eficaz dos recursos costeiros.Os objetivos do projeto PAC:MAN são investigar: 1) os dados de acidentes passados para desenvolver e validar um conjunto de indicadores ambientais de condições atmosféricas e oceanográficas propícias à ocorrência de derrames; 2)a capacidade e eficiência de sistemas de modelação de elevada precisão para prevenção e previsão do risco de derrame, incluindo todos os processos de transformação do óleo na zona costeira; 3) a fiabilidade, vantagens e escalabilidade de um sistema de alerta baseado em novas tecnologias móveis; 4) a capacidade dos sistemas de tecnologias de informação para integrar e disponibilizar informação ambiental relevante sobre os elementos ecológicos em risco; e 5) o modo como estes vários aspectos inovadores podem ser integrados num sistema de gestão de risco para alerta precoce e aviso da ocorr~encia de um derrame nas zonas costeiras.f3p6DHA/GT
Transition zones in railway tracks: An experimental and numerical study on the structural behaviour
No full textEste registo pertence ao Repositório Científico do LNECThe 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’s support conditions, such as transition zones to bridges or other structures. To mitigate this
problem, modern lines comprise specifically designed backfills with high-performance geomaterials to
provide an adequate approach to the structures. However, the problem of track degradation at
transition zones is far from being completely solved.
The research presented in this Thesis aimed at providing insight into the structural behaviour of
transition zones using a novel and integrated approach to investigate the problem, contributing to an
efficient management of railway assets, in the context of the life-cycle cost reduction paradigm of the
railway system, in particular, the railway track.
In the scope of a research project involving LNEC, FEUP and REFER, a 30 km-long railway line is
used as case study and its construction is followed up closely. Laboratorial characterisation of bound
and unbound granular material used in transition zones is carried out, in particular using cyclic load
triaxial tests on large specimens. Thorough in situ characterisation of the track substructure is
performed, including specific portancemètre surveys at transition zones. The deformation of the
backfill of a transition zone case study to a bridge is monitored using different techniques, including
sub-horizontal inclinometers installed during construction. The results obtained regarding the
substructure at transition zones indicate that the design of the backfills was successful in minimizing
settlements and achieving a gradual stiffness increase at the approach to the structures. The analysis of
the evolution of the geometric quality of the line evidenced higher degradation rates at some transition
zones and other track singularities, mostly associated with abrupt changes in the track substructure.
To fill the gap between experimental and numerical studies, extensive field measurements are
presented and used to calibrate and validate FEM models that consider the relevant track components
of the superstructure and substructure. The models also account for the dynamic train-track interaction
and are very accurate in reproducing the measurements. The experimental works comprised dynamic track characterisation with receptance tests and a new approach using the light falling weight
deflectometer. Innovative solutions for transition zones, such as under sleeper pads (USP), are also
analysed in detail in specific case studies of transition zones to underpasses. The experimental results
evidenced the increase in the vertical stiffness of the track at the approach to structures, which could
suggest the amplification of the dynamic track-interaction. However, because the design of the
backfills provides a smooth stiffness variation and the track evidenced a very good track quality, the
simulations indicated limited dynamic amplifications of the train loads in the tested scenarios. As
regards USP, simulations suggested a beneficial contribution to reduce track degradation rates, but a
careful design is required to prevent excessive dynamic amplifications when trains enter or exit
sections of the track with USP.
Later, the effect of the differential settlements on the dynamic response of the train-track system at the
approach to structures is investigated. To that aim, comprehensive parametric studies using numerical
simulations are carried out. The results of the simulations are integrated and used to establish
performance indicators that affect the train-track interaction, based on the length and amplitude of
track defects. A novel approach is then presented and applied to the line under study, in an attempt to
associate the results of the parametric studies with locations denoting rapid track degradation or other
critical scenarios. Tools and actions are suggested to Railway Infrastructure Managers to monitor the
performance of transition zones and for a more efficient management of the infrastructure.Dissertation submitted to the Faculty of Engineering of University of Porto
in partial fulfilment of the requirements for the degree of
DOCTOR OF PHILOSOPHY IN CIVIL ENGINEERING
Supervisor: Eduardo Manuel Cabrita Fortunato (Senior Research Officer,
LNEC; Visiting Associated Professor, FEUP)
Co-Supervisor: Rui Artur Bártolo Calçada (Full Professor, FEUP)DT/NI
Design and methodology of iWIDGET system validation
No full textEste registo pertence ao Repositório Científico do LNECThis report describes the standardized methodology developed within iWidget project for performing a comprehensive full scale on-line testing of the prototype iWIDGET system peformed by households and utility stakeholders. The on-line testing method execution uses real-time datasets and is performed by real end-users (both for the water utility widgets and consumer widgets).Report MS35. Project iWIDGETDHA/NE
Proposal of a methodology for the architectural design of timber houses
No full textThis paper presents the principles of a method for the architectural design of timber houses based on the experience gained by timber companies. This proposal has as its major goal the challenging of the scenario of countries like Portugal where a shift in the design and construction methods integrating wood as a material could result in a much more sustainable habitat. A set of interviews was carried out with Portuguese companies in the sector of timber houses. They were questioned about their customers, design methods, the architect’s role and the choice of structural systems. Based on the interviews it was possible to characterize the market and identify the main procedures about design. The most relevant ones were the importance of the architectural type definition, the support of a catalog, the relationship between formal and structural types and the architect’s lack of knowledge about timber. The collected information pointed to an architectural design method to be used by Portuguese architects who, until now have often played a secondary role when a timber house was designed partly because the timber companies dominate the whole process. Some of these companies offer catalogues of design solutions that support customer’s choices. The architects generally reject this type of method because of its supposed uncreative and impersonal results. The method here presented through some basic principles aims at collecting some positive lessons from the catalogue method, defining a process based on the recognition of Formal types and Construction types. This is the framework of a tool intended to help the Portuguese architects to deal with the range of the options available (solutions, companies, structural systems) and a support to help in deciding which construction system to choose.8This paper was only possible due to the friendly collaboration of the following Portuguese enterprises: Casema, Carmo, Colicapela, Fuldex, Ideawood, Jular, Lacecal, Logdomus, Loghomes, Novo Habitat, Pinho Casa, Portilame, Rusticasa, Toscca and Tisem. We particularly want to thank the persons (managers, technicians and commercial technicians) from each company, who dedicated part of their time to participate in the interviews: Nuno Rebocho, Susana Valente, Tiago Antunes, Carlos Silva, Amilcar Rodrigues, Helder Santos, João Carmo Simões, Sérgio Barbosa, Pedro Teles, Elisabete Ferreira, Veascelav, Luís Rocha, Berta Villas, Pedro Pinhão and Luís Jorge. We also wish to thank the support of FCT - Fundação para a Ciência e Tecnologia do Ministério da Ciência, Tecnologia, e Ensino Superior.DE/NC
Análise e interpretação do comportamento observado da barragem de Rebordelo durante o primeiro enchimento da albufeira e primeiro período de exploração
No full textApresentam-se os aspetos relevantes da análise e interpretação do comportamento observado da barragem de Rebordelo, no rio Rabaçal, em Trás-os-Montes, durante o primeiro enchimento controlado da albufeira, ocorrido no início de 2005, e nos primeiros anos de exploração, com base na observação das ações e das respostas, bem como na utilização de modelos matemáticos para resolução dos problemas térmico e estrutural.
Nas análises térmica e estrutural consideraram-se: i) um modelo tridimensional da barragem e do maciço rochoso de fundação, resolvido pelo método dos elementos finitos; ii) o comportamento viscoelástico do betão; e iii) a variação das ações da água sobre o paramento de montante e das ações térmicas no corpo da barragem.
As grandezas observadas e os resultados numéricos apresentaram uma boa concordância, atestando a adequabilidade dos modelos de comportamento utilizados e o bom desempenho da obra.16pDBB/N
Controlo de qualidade da espessura do betão de recobrimento das armaduras nas estruturas
No full textHoje em dia é praticamente consensual no seio da comunidade científica que a insuficiência da espessura do betão de recobrimento é uma das principais causas de deterioração prematura das estruturas de betão armado por corrosão das armaduras. Contudo, a maioria das normas de execução que lidam com questões de durabilidade não fornecem indicações para uma adequada inspeção e controlo da conformidade da espessura do betão de recobrimento nas obras. Para tal, foi desenvolvido pelo comité técnico da RILEM TC 230-PSC Performance-based specifications and control of concrete durability, um documento técnico com um conjunto de linhas orientadoras e regras para a inspeção da espessura do betão de recobrimento, adaptadas ao tipo de estrutura a inspecionar. Nesta comunicação são descritas, sumariamente, as metodologias apresentadas no referido documento.1-12 pp.DM/CHEFI
Assessment of intermodal freight transport costs
No full textThe research reported in this paper is part of the R&D project COST-TRENDs, funded by the Portuguese Foundation for Science and Technology. It presents a strategic assessment study of the hinterland connections centred in the Port of Sines, in Portugal, that integrates the core network corridor of the Trans-European Transport Network (TEN-T) designated as the Atlantic corridor. The study comprised the analysis of trends of maritime freight costs until 2020 and the assessment of alternative intermodal freight transport options to reduce costs along the multimodal transport chains. The options evaluated focused in the Iberian section of the Atlantic corridor and included the combination of maritime-short sea shipping, maritime-rail, maritime-road and, also, rail-air modes. The study estimated several key performance indicators for each option which aim to provide useful inputs to transport policy.16ppArtigo apresentado na sessão "Ports in Maritime Supply Chains"(13:30h - 15:30h) da Conferência Europeia de Transportes 2014, no dia 29 de Setembro de 2014DT/NPT