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Degradação dos solos e desertificação: Principais ameaças
No full text30-31pp.N.º 93DG/NGEAIndustria e Ambiente – Revista de Informação Técnica e Científic
Interpretation of an injection test in a large diameter well in south Portugal and contribution to the understanding of the local hydrogeology
No full textThis paper refers to the interpretation of an injection test in a traditional large diameter well in Querença-Silves aquifer, south Portugal, under the scope of the project FP7-ENV-2013-WATER-INNO-DEMO MARSOL. Hydraulic parameter estimates were found within a high level of uncertainty regarding aquifer and well configuration. Given the injection test results together with the knowledge acquired on the field and from previous well logs and pumping tests
on this aquifer section, it seems plausible to assume that the water injected in the well is locally flowing to an opposite direction to the regional aquifer flow. This forcing could possibly be caused by the existence of a local confinement or aquitard separating the injection well from the regional aquifer, or simply due to local scale heterogeneities and fracturation patterns.05pDHA/NR
Erosões localizadas junto de pilares de pontes sobre leitos aluvionares
No full textEsta comunicação reúne contribuições recentes de estudos dos autores
sobre os efeitos da altura relativa do escoamento, da dimensão relativa dos
sedimentos do leito, do tempo, da forma dos pilares e do seu ângulo de viés em
relação à direção do escoamento na profundidade de equilíbrio de cavidades de
erosão que se desenvolvem junto de pilares simples. Estas contribuições baseiam-se
em campanhas experimentais de características únicas, no sentido em que foram
sistematicamente conduzidas com durações superiores às da vasta maioria dos
trabalhos publicados na literatura. A caracterização de parte daqueles efeitos é
claramente mais completa e rigorosa por comparação com o que se encontra
publicado em literatura da especialidade enquanto, noutros casos, se confirmam
resultados anteriormente publicados. Sugerem-se critérios de previsão da
profundidade de erosão que incorporam as novas contribuições dos autores.9pISBN: 978-989-98405-2-2DHA/NRELivro de Atas: "Concepção, Conservação e Reabilitação de Pontes
Normalização na gestão patrimonial de infraestruturas
No full textAs normas ISO 55000:2014, ISO 55001:2014 e ISO 55002:2014 são destinadas a serem utilizadas para gerir ativos físicos em particular, podendo ser aplicadas também a outros tipos de ativos. Portugal participou ativamente na sua elaboração, tendo dado atenção particular à aplicabilidade das normas aos ativos que constituem infraestruturas públicas e que funcionam como sistemas em rede, como são os casos dos sistemas urbanos de água.
O presente artigo pretende dar a conhecer o trabalho de tradução das normas para português, resultante do trabalho conjunto das Comissões Técnicas de Normalização CT94 e CT90. Pretende também evidenciar o grande potencial de aplicação aos sistemas urbanos de água, sem deixar de incluir recomendações de implementação a este setor de atividade. Tem ainda em vista destacar o proveito decorrente da sua utilização para estruturar a gestão patrimonial de ativos de sistemas urbanos de água.14pComunicação apresentada no Encontro Nacional de Entidades Gestora de Água e Saneamento ENEG 2015, APDA, Porto, 1-4 DezembroDHA/NE
Micro-drilling studies in azulejo consolidation
No full textThe consolidation treatment of azulejos is indispensable when there is a debilitated or disaggregated ceramic biscuit and/or one wishes to reestablish a weakened glaze-ceramic adherence.
In this communication the impregnation profiles obtained via mass consolidation on ceramics conservation are presented. An acrylic resin, an ethyl silicate and a nanolime were used to determine the micro-drilling relevance for the evaluation of consolidation treatments applied on ceramics.
This technique allowed to observe the impregnation patterns which cannot be determined by the mechanical strength tests (flexural and compression) commonly used to evaluate the consolidation effect.269-278pp.The authors acknowledge the financial support for the execution of this work (Project CerAzul: PTDC/CTM-CER/119085/2010).
The participation of LNEC researchers is encompassed by Project 0202/111/19014 (IPERION-CH.pt)DM/NBPCProceedings of the International Conference Glazed Ceramics in Architectural Heritage (GlazeArch 2015
Experimental and numerical study of a chute spillway
No full textThis paper presents a combined approach, including CFD numerical and scale
physical modelling, to address the hydraulic behavior of the spillway of a dam.
The spillway studied is an open channel flow which crosses the right abutment of the
dam, it runs in that part of the hillside and it has three separate spans controlled by
Taintor Gates of 9.5 x 6.8 m. The design flow of the spillway is 1,648.5 m3/s and the
verification flow is 1,885.4 m3/s.
Choosing and setting the spillway different forms, such as feeding, piers, gates
positioning, curve at the beginning of the chute, spans convergence, height of the walls
and bucket type, was performed after analyzing numerous options and through numerical
methods in fluid computational hydraulics. The software used was FLOW 3D, it solves
Navier Stokes equations by finite differences. The different options are now being verified
on a physical scale model in the Laboratório Nacional de Engenharia Civil (LNEC).
The use of numerical methods in fluid computational hydraulics is very useful when used
by the designer in combination with the physical modelling. It allows analysing different
options until getting hydraulically optimal solutions which can be tested in a laboratory.
This method provides undisputed advantages in the technical field as well as on the use of
time and resources.
In this presentation there are a variety of approaches created by fluid computational
hydraulics in relation to the spillway dam. It is analysed the hydraulic behaviour of the
different options and the results of numeric model are compared with the obtained in tests
carried out in the physical scale model.12ppDHA/NR
Life cycle assessment as a tool to promote sustainable thermowood boards: a portuguese case study
No full textThe aim of the present work was to conduct a Life Cycle Assessment study of
thermally-modified Atlanticwood® pine boards based on real data provided by the
Santos & Santos Madeiras company. Atlanticwood® pine boards have several
applications, but are mainly used for exterior decking and the cladding facades of
buildings. The LCA study was conducted based on the ISO 14040/44 standard and PCR
“Product Category Rules for preparing an environmental product declaration for
Construction Products and Construction Services”. Because the precise function of the
product or scenarios at the building level is unknown the declared unit is used instead of
the functional unit. The declared unit is applicable for an EPD that covers “cradle to
gate” and in this case is 1 m3 of Atlanticwood® pine boards. The inventory datasets for
the products and processes included in the system boundaries were obtained from the
company (specific data). Generic data were obtained and adapted as necessary from the
Ecoinvent 3.1 database and from Franklin USA. The inventory analysis and,
subsequently, the impact analysis was carried out using the SimaPro8.0.4 LCA software
and associated databases and methods. The method chosen for the impact assessment
was EPD (2013) V1.01. The results show that more than ¾ of “Acidification”,
“Eutrophication”, “Global warming” and “Abiotic depletion” caused by 1 m3 of
Atlanticwood® pine boards production is due to energy consumption (electricity + gas
+ biomass). This was to be expected since the treatment is based on the production of
heat and no chemicals are added during the heat treatment process.9pThe authors would like to thank the the Center for Studies in Education, Technologies
and Health (CI&DETS) of Polytecnic Institute of Viseu and the Portuguese Foundation
for Science and Technology (FCT).DE/NC
Wave propagation on a flume: numerical simulation
No full textThis paper presents the numerical simulations done by using the waves2Foam, an OpenFOAM® library, to simulate the propagation of regular waves without breaking in a three-dimensional flume. The numerical code solves the unsteady Navier-Stokes equations and uses a Volume-of-Fluid (VoF) method to identify the free surface. A regular incident wave with a 1.5s period and 0.1m wave height, was considered. This is one of the conditions from the wide range of wave flume tests conducted at the National Laboratory for Civil Engineering (LNEC) whose objective was to analyze the hydrodynamics of wave transformation and wave breaking for different incident conditions over a variable bathymetry. Comparisons are made between the numerical and the experimental results. These comparisons include time-series of wave-gauges records at several locations along the flume and the corresponding amplitude spectra; significant wave height and average period evolution along the flume; time-series of the velocity components at one section of the flume, measured at the middle of the water column; and hodograph representation of the velocity components, in the middle of the water column, in the xy, xz, and yz planes along the flume. It was found that the numerical results obtained are close to the experimental data. The observed differences are attributable to numerical inaccuracies as well as the differences between the wave generation method in the numerical and experimental tests.95-102ppVol 14 - nº 1DHA/NPEEngenharia Térmica (Thermal Engineering
Força de impacto num quebra-mar vertical: comparação entre um modelo numérico SPH e formulações empiricas
No full textO conhecimento dos esforços resultantes da interacção de uma onda com um quebra-mar vertical
torna-se essencial no dimensionamento deste tipo de estruturas. No presente trabalho, o modelo numérico SPHyCE, baseado numa metodologia de tipo SPH - Smoothed Particle Hydrodynamics, é utilizado para o cálculo das forças num quebra-mar vertical. Para analisar a evolução das forças de impacto foram consideradas várias condições de profundidade no pé da estrutura e de altura de onda incidente abrangendo diferentes regimes de forças. A comparação dos resultados do modelo numérico com os das formulações empíricas permitiu verificar que as forças previstas são semelhantes para os casos de regime de onda parcialmente estacionária. No entanto, para o regime de forças de impacto, existem diferenças que se devem a diversos factores: i) a rebentação da onda no modelo SPHyCE pode não corresponder necessariamente à forma de rebentação prevista nas formulações empíricas; ii) no caso da rebentação com aprisionamento de ar, cuja influência no valor das forças é relevante, o modelo numérico atinge o seu limite de aplicação, pois não integra o ar e não existem formulações aplicáveis; iii) as formulações empíricas aplicáveis com rebentação dão valores claramente por excesso.3-26ppVol. 19, N.º 2DHA/NPERevista Iberoamericana de Ingeniería Mecánic
Sewer asset management planning – implementation of a structured approach in wastewater utilities
No full textWastewater services are fundamental for the protection of public health and environment, population well-being and sustainable development of communities. The value of urban water assets represents a major part of all public infrastructures. These assets must be managed rationally and efficiently, justifying investment priorities in a clear and straightforward way. Effective decision-making requires a comprehensive approach allowing the incorporation of desired performance at acceptable risk levels, considering investment and operational costs. Advanced sewer infrastructure asset management (IAM) is key to achieve and ensure adequate future levels of service, in issues such as flooding of urban areas, pollution prevention, balancing performance, risk and cost. The paper illustrates the integration of different support tools and methods by implementation of the AWARE-P procedure for planning IAM, demonstrated by the experience of fourteen wastewater utilities. Results showed the effectiveness of the tools and methods at different stages of the AWARE-P methodology.14pDOI:10.1080/1573062X.2015.1076859CD/CDUrban Water Journa