Artigos de Revista

Depois de uma introdução ao artigo, onde se salienta o respetivo enquadramento na série editorial, que é também minimamente apresentada, avança-se numa reflexão sobre como apoiar a proposta de uma renovada Habitação de Interesse Social Portuguesa (HISP), que aproveite o melhor que se fez nos cerca de 100 anos de história da HISP, com relevo para os numerosos casos de referência concretizados no último quarto de século de promoção ativa de Habitação a Custos Controlados (HCC) apoiada pelo INH/IHRU. Abordam-se, em seguida, os aspetos de reflexão prospetiva sobre o que poderá ser a nova HISP de um modo mais sistemático, em termos dos diversos níveis físicos residenciais e urbanos considerados: vizinhança alargada; vizinhança próxima ou de proximidade; edifício multifamiliar; edifício unifamiliar; habitação. Sempre que é considerado pertinente discute-se, também, a aplicação de variadas e inovadoras tipologias, designadamente, em termos de edifícios multifamiliares. Em cada nível físico a abordagem é realizada através de uma reflexão qualitativa ampla e diversificada, utilizando-se uma grelha qualitativa que foi, anteriormente, devidamente estudada e discutida; em todo este desenvolvimento aproveita-se, ao máximo, o acompanhamento de muitos conjuntos de HISP, que tem sido possível, em alguns casos, ao longo de uma sua já significativa “vida”; condição esta que se reflete também numa numerosa ilustração comentada, que vai seguindo a evolução temática do texto, mas que possui significativa autonomia de leitura.

This paper presents a study of run-up/overtopping over a smooth impermeable dike with promenade using 2D and 3D mesh-based and mesh-free numerical models and results from 2D physical modelling for strong energetic incident waves. These waves induce plunging wave breaking and a complex water/air mixture turbulent flow before overtopped the dike, a challenging configuration for numerical models. The analysis is structured in two phases: (i) evaluates the results of 2D numerical and physical models for run-up and overtopping; (ii) compares qualitatively the results of 3D numerical models for overtopping over a dike with promenade between groins located in front of a slope beach. The results indicate that the main differences obtained in run-up and overtopping are due to differences in wave generation and active absorption systems used in physical and numerical models and in turbulent models used by the numerical models. These differences lead to changes on incident wave height and on wave breaking and, consequently, on reflection, run-up and overtopping over the structure. For 3D simulation, even if larger discrepancies were found on overtopping along the dike, mean wave overtopping discharge and water flow height at the crest of the groin head show a similar order of magnitude.

Earthquake damage in historic masonry buildings is generally caused by the collapse of individual portions that become detached form the structure and fail by overturning. These mechanisms are mainly governed by the discrete nature and geometry of the block units. Analyses based on explicit micro-modelling in which each block is considered separately are therefore of increasing importance. This paper offers a robust tool for the seismic assessment of masonry structures under either, quasi-static or dynamic loading. Algorithms for performing dynamic pulses and pushover analyses through the Discrete Element Method are developed and described, taking into account the actual discrete nature and geometry of masonry. A numerical procedure is proposed that automatically detects the collapse mode and follows the evolution of the analysis until collapse. The implemented method is able to give a reliable estimate of the expected failure mechanism, providing the seismic acceleration required to trigger the motion and the ultimate displacement beyond which the collapse occurs. Finally, the implemented algorithms are applied to two case studies and the results are compared with the traditional analysis based on rigid-block kinematics to outline the features and potentialities of the proposed approach.

Night natural ventilation systems have been receiving increased attention in recent years because of their energy saving potential and environmental protection when used in passive instead of active cooling. A novel system recently proposed for cooling the building concrete slab is studied numerically in the present work. The system relies only on night ventilation as a means for cooling down the structure of the building. It consists of a new type of suspended ceiling with a peripheral gap between it and the walls combined with the positioning of the air supply and extraction grilles between the ceiling slab and the suspended ceiling. This study focuses on the use of Computational Fluid Dynamics (CFD) to predict the airflow and thermal performance of this strategy for an office room. Ansys-Fluent is used to perform the calculations both for a reduced and a full-scale room. Transient simulations were performed for a period of 24 h and the predictions for the reduced-scale model were validated by experiments under different operating conditions. The results show that the mathematical and numerical models provide satisfactory predictions of the temperature evolution in the reduced-scale model, allowing the analysis to be extended for full scale. The predictions for the office room at full scale confirm the effectiveness of the proposed cooling technique, revealing that the air peak temperature during the day is lower, as well as the temperature of the slab and the temperature of the air in the plenum during the night.

Este ensaio aborda a (re)invenção do espaço urbano a partir de lógicas cocriativas e, em específico, contempla o recurso feito a matéria azulejar no âmbito deste intuito. Por um lado, tendo por referência o Projeto Europeu C3Places, discute o potencial contributo da cocriação enquanto modus operandi do produzir espaço público urbano. Por outro lado, a partir de uma perspetiva exploratória, salienta determinados aspetos observados no decorrer de mapeamento de experiências cocriativas – em Portugal e no Brasil – que, em comum, recorrem ao azulejo na (re)invenção do espaço público. A reflexão destaca o potencial das iniciativas cocriativas no incrementar de sensibilidades coletivas com o património e o ambiente urbano. Observando que as mesmas não advêm de grandes ações, mas naquelas de menor âmbito, localizadas e de cunho colaborativo. O uso feito da matéria azulejar para a dinamização de ações coletivas e colaborativas é salientado. O que permite observar que, por um lado, a partir de uma lógica de continuidade-renovação, o recurso ao azulejo, viabiliza a invenção de património. Por outro lado, a aplicação de azulejo em espaço público protagoniza uma maior atenção coletiva com o ambiente urbano. A cocriação transformativa do espaço infere uma ligação à esfera pública, o que colabora para refletir sobre o papel que pode ter no incremento de práticas sociais mais envolvidas com os lugares urbanos e sensíveis à memória, ao património e ao ambiente.

Neste artigo, dedicado a um tema que se julga dever ser “irmão” dos aspetos globais de funcionalidade doméstica e depois de uma reflexão introdutória sobre a própria natureza do respetivo título, onde contrapontuam os termos ”abrangente” e “específicos”, desenvolve-se uma reflexão sobre a implementação de uma habitabilidade ampla nos espaços domésticos, habitabilidade esta que também depende do desenvolvimento de boas condições habitacionais interiores, exteriores e de relação interior/exterior, do visar de renovados e bem fundamentados objetivos de organização doméstica e da promoção de um adequado convívio nos espaços domésticos; temas estes que se desenvolvem sequencialmente no artigo

Background. European cities are placing a larger emphasis on urban data consolidation and analysis for optimizing public transport in response to changing urban mobility dynamics. Despite the existing efforts, traffic data analysis often disregards vital situational context, including large-scale events, weather factors, traffic generation poles, social distancing norms, or traffic interdictions. Some of these sources of context data are still private, dispersed, or unavailable for the purpose of planning or managing urban mobility. Addressing the above observation, the Lisbon city Council has already established efforts for gathering historic and prospective sources of situational context in standardized semi-structured repositories, triggering new opportunities for context-aware traffic data analysis. Research questions. The work presented in this paper aims at tackling the following main research question: How to incorporate historical and prospective sources of situational context into descriptive and predictive models of urban traffic data? Methodology. We propose a methodology anchored in data science methods to integrate situational context in the descriptive and predictive models of traffic data, with a focus on the three following major spatiotemporal traffic data structures: i) georeferenced time series data; ii) origin-destination tensor data; iii) raw traffic event data. Second, we introduce additional principles for the online consolidation and labelling of heterogeneous sources of situational context from public repositories. Third, we quantify the impact produced by situational context aspects on public passenger transport data gathered from smart card validations along the bus (CARRIS), subway (METRO) and bike sharing (GIRA) modes in the city of Lisbon. Results. The gathered results stress the importance of incorporating historical and prospective context data for a guided description and prediction of urban mobility dynamics, irrespective of the underlying data representation. Overall, the research offers the following major contributions: 1.A novel methodology on how to acquire, consolidate and incorporate different sources of context for the context-enriched analysis of traffic data; 2. The instantiation of the proposed methodology in the city of Lisbon, discussing the role of recent initiatives for the ongoing monitoring of relevant context data sources within semi-structured repositories, and further showing how these initiatives can be extended for the context-sensitive modelling of traffic data for descriptive and predictive ends; 3. A roadmap of practical illustrations quantifying impact of different context factors (including weather, traffic interdictions and public events) on different transportation modes using different spatiotemporal traffic data structures; and 4. A review of state-of-the-art contributions on context-enriched traffic data analysis. The contributions reported in this work are anchored in the empirical observations gathered along the first stage of the ILU project (see footnote 1), providing a study case of interest to be followed by other European cities.

Neste artigo, dedicado a uma reflexão sobre as opções de compartimentação na habitação, inicia-se o desenvolvimento da temática com a indicação do que se considera ser a urgência da abordagem do tema e numa perspetiva ampla e integradora. Avança-se, em seguida, para a exploração de diversos caminhos de consideração das opções domésticas de compartimentação, primeiro de uma forma mais ampla e de certo modo “tipológica” e, depois, apontando-se alguns caminhos, considerados (mais) práticos da compartimentação doméstica. Depois a compartimentação doméstica é um pouco discutida tendo-se em conta a dimensão e a idade das famílias Finalmente e a modos de comentário final associa-se esta pequena reflexão sobre a compartimentação doméstica à, sempre presente, importância da qualidade arquitectónica dos respetivos projetos.

Artificial neural networks (ANN) are extremely powerful analytical, parallel processing elements that can successfully approximate any complex non-linear process, and which form a key piece in Artificial Intelligence models. Its field of application, being very wide, is especially suitable for the field of prediction. In this article, its application for the prediction of the overtopping rate is presented, as part of a strategy for the sustainable optimization of coastal or harbor defense structures and their conversion into Waves Energy Converters (WEC). This would allow, among others benefits, reducing their initial high capital expenditure. For the construction of the predictive model, classical multivariate statistical techniques such as Principal Component Analysis (PCA), or unsupervised clustering methods like Self Organized Maps (SOM), are used, demonstrating that this close alliance is always methodologically beneficial. The specific application carried out, based on the data provided by the CLASH and EurOtop 2018 databases, involves the creation of a useful application to predict overtopping rates in both sloping breakwaters and seawalls, with good results both in terms of prediction error, such as correlation of the estimated variable.