Artigos de Revista

O projeto de investigação e desenvolvimento To-SEAlert financiado pela Fundação para a Ciência e a Tecnologia e envolvendo o LNEC, a FCiências.ID, a NOVA.ID.FCT e o ISEL tem como objetivo o desenvolvimento de um sistema de previsão, alerta, planeamento de emergência e gestão de risco de galgamentos e inundações em zonas costeiras e portuárias, com base no sistema HIDRALERTA. Partindo das características da agitação marítima ao largo e utilizando modelos numéricos para a propagação e deformação da agitação marítima, o sistema HIDRALERTA estima os parâmetros relevantes da agitação marítima para a avaliação do galgamento e da inundação bem como o risco associado a esses eventos. As funcionalidades que se pretendem melhorar no âmbito do projeto To-SEAlert dizem respeito às metodologias de previsão do galgamento e da delimitação da zona inundada, bem como no apoio à resposta a situações de emergência envolvendo fenómenos de galgamento. A implementação e a validação do protótipo do To-SEAlert estão a ser efetuadas para a zona costeira da Costa da Caparica e para o porto da Ericeira. Este artigo apresenta o trabalho desenvolvido até à data na construção e desenvolvimento do protótipo do To-SEAlert para o porto da Ericeira.

RESCCUE es un proyecto de investigación financiado por el programa Horizonte 2020 de la Comisión Europea y liderado por Suez que tiene como objetivo ayudar a ciudades de todo el mundo a ser más resistentes a retos físicos, sociales y económicos, utilizando el sector del agua como elemento central.

Flood risk management in urban areas adjacent to the coast is essential to increase their resilience. This study aims at improving scientific knowledge of flood risk alongside estuaries, considering different hazards and integrating estuestuarine and urban drainage modelling. Mathematical modelling of stormwater systems is a useful tool to evaluate the susceptibility to flooding and identify potential measures to reduce flood risk.

Several authors have proposed guidelines on how to consider the effects of oblique waves on the stability of armour layers of rubble-mound breakwaters. Especially for very oblique waves, for which the increase in stability is the largest, limited data are available. Under the scope of the HYDRALAB+ transnational access project “RODBreak”, experiments were conducted in a tank at the Marienwerder facilities of the Leibnitz University Hannover (LUH), comprising measurements of sea waves, runup, overtopping and armour layer damage of a rubble-mound breakwater under oblique extreme wave conditions. This paper focuses on the analysis of damage evolution of the breakwater roundhead subject to these conditions, on the novelty of the nonintrusive survey methodologies and on the advance in knowledge on roundhead stability.

The paper investigates the effectiveness of two-dimensional Discrete Element Method as a tool for structural analysis of arches provided with buttresses and backfill and strengthened with externally bonded reinforcement. Masonry vault and buttresses are modelled as an assembly of 2D rigid blocks interacting through non-linear contact joints, the backfill is discretized into deformable elastic-plastic triangular elements, while the reinforcement is modelled by means of truss elements bonded to the substrate through non-linear springs. A parametric analysis on the influence of material parameters and the effect of the discretization of the backfill is carried out, and the outcome of different reinforcement systems, consisting of Steel Reinforced Grout applied either at the intrados or at the extrados, are analysed. The comparison with experimental full-scale tests proved the ability of the numerical approach to capture hinges position, load bearing capability, as well as the increase in deflection and load capacity provided by the reinforcement.

This paper describes a program under the responsibility of LNEC for the systematic observation and monitoring of maritime works that has successfully been applied to a number of maritime structures on the Portuguese mainland coast. The now-called OSOM+ program comprises the following four main components for each structure: i) periodic visual inspections by an experienced technician; ii) periodic aerial inspections with a UAV/ drone; iii) a ANOSOM-WEB database, to store and/or query obtained information on the observation campaigns, as well as to diagnose present, evolution and risk conditions of the structure; iv) a mobile, portable, application, for realtime input and visualization of the database information. OSOM+ has recently been updated with a number of tools and functionalities that are illustrated in this paper with applications to two real case studies: the Portimão harbor breakwaters and Faro-Olhão inlet entrance breakwaters, both located in the south coast of Portugal.

Wave energy is a renewable source with significant amount in relation to the global demand. A good concept of a device applied to extract this type of energy is the onshore oscillating water column wave energy converter (OWC-WEC). This study shows a numerical analysis of the diameter determination of two types of turbines, Wells and Impulse, installed in an onshore OWC device subjected to a hypothetical sea state. Commercial software FLUENT, which is based on RANS-VoF (Reynolds Averaged Navier-Stokes equations and Volume of Fluid technique), is employed. A methodology that imposes air pressure on the chamber, considering the air compressibility effect, is used. The mathematical domain consists of a 10 m deep flume with a 10 m long and 10 m wide OWC chamber at its end (geometry is similar to that of the Pico’s plant installed in Azores islands, Portugal). On the top of the chamber, a turbine works with air exhalation and inhalation induced by the water free surface which oscillates due to the incident wave. The hypothetical sea state, represented by a group of regular waves with periods from 6 to 12 s and heights from 1.00 to 2.00 m (each wave with an occurrence frequency), is considered to show the potential of the presented methodology. Maximum efficiency (relation between the average output and incident wave powers) of 46% was obtained by using a Wells turbine with diameter of 2.25 m, whereas efficiency was 44% by an Impulse turbine with diameter of 1.70 m.

Electric Arc Furnace steel slag aggregate has potential for wider application in railway infrastructures. Nonetheless, its use in ballast layers, as an alternative to natural crushed rock, is often restricted, which is not consistent with the sustainable construction paradigm. To characterise the morphology and performance of this material, quantitative analyses were conducted on the abrasion and 3D morphology evolution of particles by micro-Deval testing. Slag particles showed higher angularity and surface texture indices than natural granite; retained these characteristics longer; and yielded comparable or lower surface wear. These findings support the potential use of slag aggregate as an alternative ballast material.

O artigo estrutura-se em três partes: uma primeira em que se abordam os tipos de adaptabilidade e flexibilidade habitacional e a sempre essencial relação entre família e habitação; uma segunda parte em que se desenvolvem variados tipos de soluções habitacionais em termos de “célula habitacional” - estúdios individuais e para casais, soluções habitacionais para pessoas sós, pequenas habitações e grandes habitações multigeracionais e multifuncionais; e, finalmente, uma terceira parte dedicada aos espaços e serviços domésticos comuns e aos serviços comuns e domiciliários e aos equipamentos coletivos de proximidade.

O Regulamento Geral das Edificações Urbanas (RGEU), aprovado pelo Decreto-Lei n.º 38 382, de 7 de agosto de 1951, define exigências gerais relativas à construção, saúde, segurança e estética das edificações urbanas, constituindo o diploma de cúpula da regulamentação técnica da construção. Não obstante o RGEU ter sido objeto de diversas alterações, cumprir os requisitos nele definidos, sobretudo os relativos ao dimensionamento dos espaços, coloca dificuldades nas obras em edifícios existentes. Para ultrapassar essas dificuldades foi publicada a Portaria n.º 304/2019, de 12 de setembro (doravante designada apenas de Portaria), que definiu os requisitos funcionais mínimos da habitação e da edificação em conjunto . Neste artigo analisa-se como a Portaria adequou o RGEU à especificidade das obras em edifícios existentes, comparando os requisitos funcionais estabelecidos nos dois diplomas. A exposição segue a organização da Portaria, com 4 secções e 18 artigos, e termina com algumas conclusões.