Artigos de Revista

In regions with a strong seasonal or interannual asymmetry in the distribution of precipitation and higher frequency of droughts, collective irrigation systems are vital infrastructures for agricultural activity. Although operating for decades, several systems have ageing infrastructures, with relevant water losses and pumping energy inefficiencies. Consequently, the systems are not adequately designed or operated to meet current and future water demand. Therefore, rehabilitation to improve water and energy efficiency while ensuring infrastructure, economic sustainability and service quality is crucial. In this sense, comprehensive approaches using performance assessment to support the planning process or benchmarking between water users associations play an essential role in improving efficiency in collective irrigation systems.

Given the 516 Arouca pedestrian suspension bridge

Storms impacting sandy coastal areas produce hazards such as erosion and overwash that, in turn, promote risk to life and property damage in occupied areas. Coastal damage and risks willincrease in the future not only in association with climate change but also due to the growinghuman occupation in coastal areas (van Dongeren et al., 2018). Since the threatened coastal areas are often densely populated, there is a need to implement measures to prevent risks. One of such measures is the use of Early Warning Systems (EWS) that anticipate expected risks and, therefore, work as management tools to minimize or avoid disaster. This work presents the basis of an EWS prototype to alert about the potential consequences of overwash/overtopping and erosion induced by storms, in coastal areas.

Population growth and social and economic development demand increasing volumes of water for public supply, especially in scenarios where surface sources such as rivers may not meet the basic demands for the population. In southeastern Brazil, with emphasis on the Piracicaba region, there is a conflict over water use regarding agricultural and industrial activities, where the sugar-alcohol sector is widely highlighted. The region has thousands of hectares of sugarcane cultivated, which requires intensive use of fertilizers and pesticides, in addition to the need for large volumes of water in the production of sugar and ethanol, where the main effluent produced is represented by vinasse, used as fertilizer complement and soil hydration in sugarcane fields. This work presents the results of a geophysical diagnosis in a closed wetland, located in a sugarcane field region, to evaluate the hydrogeological function of this environment in aquifer recharge and the risks that land use can cause in the quality and availability of surface and underground water resources.The geophysical survey consisted of nine lines of electrical resistivity tomography in Schlumberger arrangement, submitted to 2D processing and inversion followed by interpolation and generation of 3D visualization models. The results indicate a direct connection between water accumulated in the wetland and the aquifer underneath, separated by an aquitard interface about 44 m thickness. The study points out to the high vulnerability to the input of pesticides and vinasse effluent from the surrounding sugarcane fields to the interior of the wetland, given the absence of riparian forest or buffer zone, in addition to the risk of contamination of surface and groundwater. Understanding the local hydrological dynamics should subsidize the sustainable use of the soil providing preservation of water resources, with emphasis on aquifers, a source of increasing importance in the face of the imminent scarcity of surface resources.

Along the Portuguese coastline, several military fortifications were built with the intentionto protect the territory from the constant military threat from the sea. These constructions have beensubjected, during centuries, to a very aggressive environment; the renders, whose main functionis the protection of walls, are particularly exposed to such actions. Nossa Senhora dos Anjos dePaimogo

Beaches combined with sloping structures are frequently the frst element of defense to protect urban areas from the impact of extreme coastal fooding events. However, these structures are rarely designed for null wave overtopping discharges, accepting that waves can pass above the crest and threat exposed elements in hinterland areas, such as pedestrians, urban elements and buildings, and vehicles. To reduce risks, Early Warning Systems (EWSs) can be used to anticipate and minimize the impacts of fooding episodes on those elements. A key aspect of these systems is the defnition of non-admissible discharge levels that trigger signifcant impacts. However, large discrepancies in defning these discharge levels and the associated impacts are found among the existing methods to assess foodings. Due to the lack of standardization, a new conceptual and quantitative four-level (from no-impact to high-impact) categorization of food warnings (EW-Coast) is proposed. EW-Coast integrates and unifes previous methods and builds on them by incorporating feld-based information. Thus, the new categorization successfully predicted the impact level on 70%, 82%, and 85% of the overtopping episodes afecting pedestrians, urban elements and buildings, and vehicles, respectively. This demonstrates its suitability to support EWSs in areas vulnerable to wave-induced fooding.

Melby presents a formula to predict damage evolution in rubble-mound breakwaterswhose armour layer is made of rock, based on the erosion measured in scale-model tests and thecharacteristics of the incident sea waves in such tests. However, this formula is only valid for armourlayers made of rock and for the range of tested sea states. The present work aims to show howthe Melby methodology can be used to establish a similar formula for the armour layer damageevolution in a rubble-mound breakwater where tetrapods are employed. For that, a long-durationtest series is conducted with a 1:50 scale model of the quay section of the Ericeira Harbour breakwater.The eroded volume of the armour layer was measured using a Kinect position sensor. The damageparameter values measured in the experiments are lower than those predicted by the formulationfor rock armour layers. New ap and b coefficients for the Melby formula for the tested armour layerwere established based on the minimum root mean square error between the measured and thepredicted damage. This work shows also that it is possible to assess the damage evolution in scale model tests with rubble-mound breakwaters by computing the eroded volume and subsequently, thedimensionless damage parameter based on the equivalent removed armour units.

Buildings are subjected to deformations of their reinforced concrete structure due to vertical loadsthat can lead, in certain cases, to the significant cracking of the unreinforced masonry (URM) infill walls,therefore requiring the development of specific knowledge of these types of deformations in order to minimisethem.Aiming the evaluation of buildings with reinforced concrete structures subjected to vertical deformations, themechanical characteristics of their infill masonry walls, as well as of their interface with the supportingconcrete elements, are here analysed. The basic compression behaviour of brick masonry is assessedparticularly through the previous analysis of a vertical compression test of a masonry specimen. Themechanical behaviour characteristics of the constituents (bricks, and mortar joints) are analysed to account fortheir influence on the compression behaviour of masonry infill, aiming particularly for the prevision of theircracking in case of vertical deformations of the supporting reinforced concrete (RC) elements. Based on thatevaluation, the analysis of masonry walls subjected to vertical deformations of their supports is made throughthe assessment of the relevant characteristic behaviour of masonry wall-beam/slab assembly in case of verticalload. A general modelling approach of the behaviour of URM infills and the interaction with their supports isgenerally accessed. Finally, the preventive control of deformations of masonry wall-beam/slab assembly isdiscussed.

A avaliação do dano causado pela agitação incidente em modelos físicos de quebra mares de taludes pode ser realizada comparando volumes e profundidades erodidas entre levantamentos consecutivos de cada talude.Atualmente, estes levantamentos podem ser realizados de forma não intrusiva, recorrendo a técnicas fotogramétricas, a laser scan ou a sensores de posição baseados na metolodologia Time of Flight (ToF). Dependendo das condições de levantamento e da metodologia de pós-processamento das nuvens de pontos obtidas, estas técnicas permitem obter modelos tridimensionais de superfície, com elevada precisão.Em detalhe, as diferenças de volume entre os levantamentos inicial e

A aplicação de produtos de aço em construções de betão armado em Portugal depende da sua prévia Classificação e Certificação.O presente artigo apresenta um estudo comparativo sobre graus de confiança conferidos pelos planos de amostragem e pelos critérios de aceitação estabelecidos nos Procedimentos de Certificação aplicados em Portugal e nas normas EN 10080 e ISO 6935-2, para diferentes características essenciais dos varões de aço, em cada ação de controlo deste produto. Os graus de confiança associados a amostras com resultados nãoconformes são discutidos em pormenor, apresentando-se vários quadros e figuras com a representação da probabilidade de rejeição (ou de aceitação) de lotes não conformes, em função da dimensão das amostras e do número de resultados individuais não conformes. É ainda analisado o critério de avaliação estipulado no Anexo Nacional da EN 13670, sobre a execução de estruturas de betão, para os ensaios de receção dos varões em obra.