Browsing by Author "Abreu, Tiago"
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- Analysis of Nonlinear Wave Parameters on Ofir Sandy Beach (NW Portugal)Publication . Abreu, Tiago; Silva, Paulo A.; Baptista, Paulo; Pais-Barbosa, Joaquim; Fernández-Fernández, Sandra; Ferreira, Caroline; Matos, JoãoThe characterization of wave transformation processes in the nearshore is of paramount importance when it comes to assessing storm and flooding impacts, sediment transportation and deposition, harbors safety or design of coastal protective structures. This study analyzes nonlinear wave parameters on Ofir sandy beach. This beach is located along the northwest Portuguese coast which is a highly energetic coast exposed to waves generated far away in the Atlantic Ocean. Despite the existence of rocky outcrops in the nearshore and intertidal zones at the study site, reducing the wave energy that reaches the beach, the study site exhibits pronounced erosive processes. Field observations of six near-bottom pressure records collected at the intertidal zone help to characterize the evolution of wave nonlinearities which are directly associated with sediment transport mechanisms. Data results show that there is an interrelation between the characteristics of the waves and the local morphology. It is also possible to ascertain, more clearly, the level of asymmetry present in the waves propagated at different depths, contributing to a better understanding of the local morpho-hydrodynamics.
- Coastal management risk analysis of an embayed beach in Majorca islandPublication . Abreu, Tiago; Parreño-Mas, Benjamín; Pinto-Faria, JoséCoastal erosion affects many coastlines around the world. This is a serious problem for the Balearic Islands, located at the western Mediterranean Sea, since the economy of the region largely relies on tourist activities along the sandy coastline. Therefore, coastal management strategies are required, particularly, in anthropized coasts as it is the case of Cala Millor beach (north-eastern Mallorca). A risk analysis for this micro-tidal sandy beach is performed in this paper. It is recognized that the beach suffers a persistent loss of sediments since its natural balance was changed due to anthropic activities that took place in that Spanish coast in the 1960s. Some solutions can be adopted to solve this problem, but it is important to be aware that, close to the shore, the seabed is covered by a native vegetation known as Posidonia Oceanica. This seagrass meadow plays an important role in this coastal system, being responsible by the lamination of the waves through energy dissipation, which are inextricably linked to coastal morphology. Therefore, any solution needs to address local specificities, and its consequent potential impact must be incorporated into the coastal risk management process. This study analyzes the failure modes identified according to the failure modes and effects analysis/failure mode, effects and criticality analysis, proposing a set of recommendations, in order to mitigate the occurrence of failure modes and to minimize risks.
- Evaluation of potential tidal impoundment energy systems in Ria de Aveiro, PortugalPublication . Rocha, João; Abreu, Tiago; Felgueiras, CarlosThe shelving of the seabed and funneling of the water by the estuaries is favorable for tidal impoundment technologies. In this work, the estimation of the tidal potential energy for Ria de Aveiro lagoon was achieved through the application of a model developed in the Delft3D software. This software can reproduce the hydrodynamics of this complex system and simulations were run to identify hot spots to retrieve gravitational potential energy. For the selected places, both power and annual energy were calculated. It was concluded that the tidal energy that can be extracted from Ria de Aveiro is considerable, justifying further studies to consider the accommodation of some type of tidal exploitation, in the foreseeable future.
- From engineering geosciences mapping towards sustainable urban planningPublication . Chaminé, Helder I.; Teixeira, José; Freitas, Liliana; Pires, Ana; Silva, Rui S.; Pinho, Telma; Monteiro, Rosália; Costa, Ana Lúcia; Abreu, Tiago; Trigo, José Filinto; Afonso, Maria José; Carvalho, José MartinsMaps are of key topical importance in urban geoscience and engineering practice, mainly in field data synthesis and communication related to a number of fields, such as geomatic techniques, applied geology and geomorphology, engineering geology, soil and rock geotechnics, slope geotechnics, subsurface site geotechnical investigations, urban hydrology, hydraulics and sanitation, coastal zones management, urban geoarcheology and heritage, planning and land use. The value of preparing engineering geoscience maps and plans specificallyfor urban engineering purposes are still a challenging task, particularly to end-users and planners. Nowadays, the application of Geographic Information Systems to geosciences and engineering has become more common. This paper emphasises the importance of an accurate ground field survey and inventory at several scales, GIS mapping and databases, and integrated multidisciplinary urban studies as useful tools to support a sustainable land use planning. Some selected sites are highlighted to demonstrate the importance of urban mapping for land use planning. Thus, in this study the significance of a smart urban geoscience approach is stressed.
- Integrative Groundwater Studies in a Small-Scale Urban Area: Case Study from the Municipality of Penafiel (NW Portugal)Publication . Freitas, Liliana; Chaminé, Helder I.; Afonso, Maria José; Meerkhan, Helen; Abreu, Tiago; Trigo, José Filinto; Pereira, Alcides J. S. C.The occurrence of groundwater in urban hard rock areas is mostly controlled by secondary permeability caused by the fracturing degree and weathering grade. Vulnerability GIS-mapping, monitoring, and infiltration/recharge of water resources, and the delineation of the environmental protective background are key issues in evaluating, planning, managing, and decision-making for urban water systems. A small-scale urban area in Penafiel City was used as a case study. Historical and current scenarios were compared using hydrogeological GIS-based modelling. Water sources and potential contamination sources were mapped around the study area. Groundwater is mainly acidic, with a low mineralization and a Cl-Na to Cl-SO4-Na or Cl-Ca to Cl-SO4-Ca hydrogeochemical facies. Considering potential contamination sources, the moderate and the moderate-high classes dominate the area. The combined approach of the vulnerability indexes suggests that most of the area has a low to moderate vulnerability to contamination. The Infiltration Potential Index in urban areas (IPI-urban) indicates the prevalence of a low to moderate infiltration. Groundwater recharge evaluation indicates values < 2.3 mm/year and <60 mm/year for summer and winter scenarios, respectively. Finally, the investigation addresses insights for decision-makers for the appropriate planning and sustainable management of groundwater resources in small-scale urban areas.
- Inter- and intra-annual variability of wave energy in Northern mainland Portugal: Application to the HiWave-5 projectPublication . Silva, Kássio; Abreu, Tiago; Oliveira, Tiago C.A.Ocean wave energy capacity has been pointed out as one of the unexplored renewable energy sources to help reach net zero carbon emissions by 2050, contributing to meeting the European Green Deal targets. However, despite the broad range of wave energy converter technologies already developed in a sustainable and economic model, there is still a lack of structured projects with high performance beyond the prototype stage. This paper investigates the potential for large-scale electricity production by the innovative HiWave-5 project in Aguçadoura (on the Northern coast of mainland Portugal). Wind–wave data (1950–2020) from the ERA5 reanalysis model are used to estimate inter- and intra-annual wave energy variability in Aguçadoura. ERA5 data is compared with field wind–wave data recorded between 2012–2019 near the study area. A mean wave power resource of 25.84 kW/m is obtained, for a possible device capture equal to 119.45 kW, despite a considerable intra-annual variability (ranging between 8.03 and 47.57 kW/m) and inter-annual variability (between 18.29 and 35.47 kW/m). Results show that local wave conditions do not substantially compromise the absolute performance of the device, given its survival limitations to adverse conditions. Considering a Levelized Cost of Energy of around €60/MWh, an annual investment of €62 885 is estimated, tending to meet targets for large sustainable electricity generation with the exponential growth expected until 2030, aided by the increase of devices in an energy farm concept. Wave power resources estimated using ERA5 data can underestimate about 7.20% values obtained with the wave buoy data.
- Longshore Transport Estimation on Ofir Beach in Northwest Portugal: Sand-Tracer ExperimentPublication . Fernández-Fernández, Sandra; Baptista, Paulo; Martins, Virgínia A.; Silva, Paulo A.; Abreu, Tiago; Pais-Barbosa, Joaquim; Bernardes, Cristina; Miranda, Paulo; Rocha, Mariana V. L.; Santos, Fábio; Bernabeu, Ana; Rey, DanielThis work aims to shed some light on longshore sediment transport (LST) in the highly energetic northwest coast of Portugal. Data achieved through a sand-tracer experiment are compared with data obtained from the original and the new re-evaluated longshore sediment transport formulas (USACE Waterways Experiment Station’s Coastal Engineering and Research Center, Kamphuis, and Bayram bulk formulas) to assess their performance. The field experiment with dyed sand was held at Ofir Beach during one tidal cycle under medium wave-energy conditions. Local hydrodynamic conditions and beach topography were recorded. The tracer was driven southward in response to the local swell and wind- and wave-induced currents (Hsb=0.75mHsb=0.75m, Tp=11.5sTp=11.5s, θb=8−12°θb=8−12°). The LST was estimated by using a linear sediment transport flux approach. The obtained value (2.3×10−3m3⋅s−12.3×10−3m3⋅s−1) approached the estimation provided by the original Bayram formula (2.5×10−3m3⋅s−12.5×10−3m3⋅s−1). The other formulas overestimated the transport, but the estimations resulting from the new re-evaluated formulas also yield approximate results. Therefore, the results of this work indicated that the Bayram formula may give satisfactory results for predicting the longshore sediment transport on Ofir Beach.
- Mestrado em Engenharia Civil: Dissertação, Projeto, Estágio. Anuário 2015Publication . Félix, Carlos; Abreu, Tiago; Jacob, Ângelo; Trigo, José Castro; Pinto-Faria, JoséA unidade curricular (UC) de Dissertação, Projeto, Estágio (DIPRE) desenvolve-se no segundo semestre do último ano letivo do curso de Mestrado em Engenharia Civil (MEC) do Instituto Superior de Engenharia do Porto (ISEP). No decorrer desta UC os estudantes do MEC têm a oportunidade de se dedicar em exclusivo ao desenvolvimento de um tema do seu interesse que preencha os requisitos estabelecidos para a obtenção do grau de mestre. Este trabalho pode ser realizado em meio académico, usualmente em formato de dissertação ou de projeto, ou em ambiente empresarial, no âmbito de um estágio, resultando, neste caso, a produção de um relatório de estágio. A presente publicação identifica e apresenta os resumos de todos os trabalhos de DIPRE realizados pelos estudantes do MEC do ISEP, no ano letivo 2014/2015. Pretende-se, desta forma, promover e difundir, de modo mais eficaz, estes trabalhos, bem como os resultados que têm vindo a ser alcançados, junto da comunidade técnica e científica. Esta iniciativa resulta de uma reflexão sobre o volume de informação que tem vindo a ser produzido e da excelência que alguns destes trabalhos atingem. Espera-se, de forma convicta, que a sua divulgação contribua para o avanço tecnológico na área da Engenharia Civil e para a efetiva melhoria dos processos, estabelecendo referências para trabalhos futuros. Os resumos dos trabalhos de DIPRE, em formato de dissertações, de projetos ou de relatórios de estágio, estão organizados no presente anuário segundo as subáreas científicas ou ramos em que se organiza o MEC, nomeadamente, Construções, Estruturas, Gestão da Construção e Infraestruturas, seguindo a ordem alfabética dos seus autores.
- Mestrado em Engenharia Civil: Dissertação, Projeto, Estágio. Anuário 2016Publication . Félix, Carlos; Abreu, Tiago; Jacob, Ângelo; Trigo, José Castro; Pinto-Faria, JoséSão reconhecidas as dificuldades que os setores da construção civil e obras públicas, com repercussões no domínio da Engenharia Civil, atravessam, atualmente, em Portugal e no Mundo, fruto de uma conjuntura económica globalmente desfavorável e de uma perceção não isenta de enviesamentos acerca da importância da Engenharia Civil para a manutenção da sociedade com os padrões de segurança e de conforto nos termos que hoje conhecemos. Estas dificuldades resultam no imediato numa recessão do mercado de trabalho, mas trazem novos desafios e criam novas oportunidades a que a comunidade técnica e científica procura responder do melhor modo. O presente documento reúne os resumos dos trabalhos de Dissertação, Projeto ou Estágio (DIPRE) que os estudantes finalistas do Mestrado em Engenharia Civil (MEC) do Instituto Superior de Engenharia do Porto concluíram no ano letivo 2015/2016, com o objetivo principal de contribuir para a difusão, junto da comunidade técnica e científica, dos avanços operados na área da Engenharia Civil. A uma envolvente desfavorável e em contração, este anuário responde com um número recorde de trabalhos de DIPRE concluídos, versando temas inovadores e em áreas consideradas promissoras, a maioria dos quais desenvolvidos em ambiente empresarial. Estes factos são bem reveladores do modo como a academia e o tecido empresarial enfrentam a atual crise do setor e se preparam para os novos desafios da Engenharia Civil que se avizinham. Os resumos dos trabalhos de DIPRE, em formato de dissertações, de projetos ou de relatórios de estágio, estão organizados no presente anuário segundo as subáreas científicas, ou ramos, em que se organiza o MEC, nomeadamente, Construções, Estruturas, Gestão da Construção e Infraestruturas, seguindo a ordem alfabética dos seus autores
- Mestrado em Engenharia Civil: Dissertação, Projeto, Estágio. Anuário 2017Publication . Félix, Carlos; Abreu, Tiago; Jacob, Ângelo; Trigo, José Castro; Pinto-Faria, JoséA presente publicação, reúne os resumos de todos os trabalhos da unidade curricular de Dissertação, Projeto, Estágio (DIPRE) do Mestrado em Engenharia Civil do Instituto Superior de Engenharia do Porto, na sua edição de 2016/2017, organizados segundo as áreas de especialização em que se organiza o MEC, nomeadamente, Construções, Estruturas, Gestão da Construção e Infraestruturas, seguindo a ordem alfabética dos seus autores. Pretende-se deste modo promover e difundir estes trabalhos, e os resultados que têm vindo a ser alcançados, junto da comunidade técnica e científica.