Artigos de Revista
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A distress-based condition assessment approach of urban water assets using novel deterioration indices
This paper aims at proposing and demonstrating the application of a novel distress-based condition assessment approach to evaluate the physical condition of inspectable urban water assets based on the classification of anomalies in terms of severity, intensity and extension using three new deterioration indices. These indices are, firstly, calculated at the asset component level and, then, aggregated at the asset level and at the infrastructure level by weighing the component indices with the respective replacement cost or criticality. A condition grading classification associated with the deterioration indices is proposed. The novel distress-based condition assessment approach is applied to 22 drinking water storage tanks and 17 wastewater pumping stations located in Portugal, that have been specifically inspected for this purpose. Results of deterioration indices are compared with those obtained by the value-based condition assessment approach. Results demonstrate that the proposed approach allows a more reliable assessment of the assets
Ano: 2022
Número Páginas:
18 pp..
Autor(es): Cabral , M.; Loureiro, D.; Flores-Colen, I.; Covas, D.
Revista: Water Resources Management
Editor: Springer Link
Volume:
Volume 36, 2022.
Keywords: Urban water assets; Deterioration index; Visual inspection; Distress-based approach; Condition assessment
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A flexible particle model for rock fracture: Validation and assessment of the Influence of deformability on the macroscopic response
Circular/spherical rigid particle models that were initially applied to rock fracture studieswere not able to match the ratio of the compressive strength to tensile strength that occurs in rock.In addition, the predicted macroscopic friction angle was much lower than the known hard rockexperimental values. Several enhancements have been proposed to address these issues, namelythe use of a clumped particle logic or the adoption of polygonal/polyhedral grain structures, eitherrigid or flexible. In this work, a flexible 2D DEM based particle model (PM) that allows deformableparticles to interact in a simplified way is presented. The proposed flexible PM model keeps thecontact interaction simplicity and the reduced computational costs characteristic of circular rigidparticle models. The PM model is tested using biaxial tests and Brazilian tests. A discussion re-garding the influence of the grain deformability on the macroscopic elastic and strength response ispresented. It is shown that, when compared with a rigid model, the proposed flexible PM modelpredicts more reasonable indirect tensile strength to direct tensile strength ratio and requires asmaller value of contact fracture energy to give a good agreement with known experimental data.It is also shown that the proposed flexible PM model can predict a behaviour similar to that ob-tained using a flexible PM model through inner particle discretization that is more computationallydemanding.
Ano: 2022
Número Páginas:
27p.
Autor(es): Azevedo, N.; Braga Farinha, M. L.; Oliveira, S.
Revista: Geotechnics
Editor: MDPI
Volume:
2.
Keywords: grain deformability; discrete element; particle model; fracture; rock
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A Hybrid Particle/Finite Element Model with Surface Roughness for Stone Masonry Analysis
Circular and spherical particle models are a class of discrete elements (DEM) that have been in-creasingly applied to fracture studies of quasi-brittle materials, such as rock and concrete, due to their proven ability to simulate fracture processes through random particle assemblies repre-senting quasi-brittle materials at the grain scale. More recently, DEM models have been applied to old stone masonry fracture studies. In order to extend its applicability to structures of larger di-mensions, an enhanced hybrid particle model is here proposed that allows finite elements with a given surface roughness, provided by the discretization of the element boundary with particles, to interact with the particulate media in which they are embedded. The performance of the hybrid model is compared with that of a traditional all-particle model under uniaxial testing. It is shown that similar results are obtained, namely in the elastic phase, figures of rupture, pre-peak and post-peak behaviour, while the hybrid model allows a significant computational run time re-duction of 20% to 25% in the coarse particle assemblies. Finally, the proposed hybrid model is applied in the simulation of shear tests of stone masonry walls, dry and mortared joints, providing a reasonably good agreement with both experimental results and predictions. For the rubble masonry tests, the hybrid model allows a computation run time reduction of around 40%, when compared with an all-particle model.
Ano: 2022
Número Páginas:
20p.
Autor(es): Azevedo, N.; Lemos, J. V.
Revista: Applied mechanics
Editor: mdpi
Volume:
3.
Keywords: fracture; hybrid model; finite element; discrete element; stone masonry
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A New Standardized Inspection System for Periodic Visual Surveys of Water Storage Tanks and Pumping Stations.
The efficient planning of operation and maintenance (O&M) interventions and short-term investments requires adequate and tailored inspection protocols of existing infrastructures. The current study proposes a new standardized inspection system for periodic visual surveys of storage tanks and pumping stations of urban water infrastructures. The proposed system aims at identifying and classifying anomalies in terms of severity, intensity, and extension to evaluate the asset and its components deterioration. Inspection forms specific for water storage tanks and pumping stations are proposed. A set of 22 water storage tanks and 17 wastewater pumping stations located in Portugal were inspected using the developed system. Several anomalies
Ano: 2022
Número Páginas:
10 pp..
Autor(es): Cabral , M.; Loureiro, D.; Flores-Colen, I.; Covas, D.
Revista: Journal of Performance of Constructed Facilities
Editor: ASCE
Volume:
Volume 36 - Issue 6.
Keywords: Operation and maintenance; Water storage; Inspection system
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A novel energy balance tailored for wastewater systems
This paper presents a novel energy balance scheme tailored for assessing energy efficiency in wastewater systems. It provides a consistent method to calculate the energy components associated with wastewater transport processes, allowing the quantification of the main water-energy inefficiencies. Three assessment levels are described (macro, meso and micro-level), depending on available information and scope. This balance allows a holistic approach of wastewater systems energy efficiency, including the system layout, losses in pipes/manholes, energy associated with undue inflows, exceedance volumes and energy recovery. The energy balance is applied to realcase studies. The energy associated with undue inflows represents from 20% to 44% of the external energy, with low average efficiencies of wastewater pumping systems (34%) and inflow intrinsic energy representing 64% of the total energy. This energy balance supports the performance diagnosis and the development of energy efficiency improvement measures.
Ano: 2022
Número Páginas:
11 pp..
Autor(es): Jorge, C.; Almeida, M. C.; Covas, D.
Revista: Urban Water Journal
Editor: Taylor & Francis
Volume:
Volume 19, 2022.
Keywords: Wastewater systems; Pumping stations; Energy efficiency; Energy balance
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A novel geometry of an onshore Oscillating Water Column wave energy converter
This study aims proposing a novel geometry of the onshore Oscillating Water Column (OWC) device to increase its efficiency. A comparison between standard OWC
Ano: 2022
Autor(es): Güths, A.; Teixeira, P.; Didier, E.
Revista: Renewable Energy
Editor: Elsevier
Keywords: Numerical simulation; Renewable energy; Wave energy; Oscillating water column
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A Qualidade da Água nas origens
Na Região Autónoma dos Açores o abastecimento público de água é realizado maioritariamente com recursos a origens subterrâneas, com desinfeção prévia à distribuição. De acordo com o 6.º objetivo para o desenvolvimento sustentável das Nações Unidas, a diminuição da poluição nas origens de água é uma das formas de melhorar a qualidade da água final. A atividade pecuária ocupa 75% da superfície agrícola útil e tem vindo a tornar-se mais intensiva em algumas ilhas, o que pode constituir um foco de contaminação das origens de água. Nesse sentido, desenvolveu-se um estudo para avaliar a suscetibilidade das captações de água para consumo humano a contaminação de origem fecal e por nitrato, tendo estabelecido como critério de qualidade o Valor Máximo Recomendado no Decreto-Lei 236/98, de 1 de agosto.
Ano: 2022
Número Páginas:
6 pp..
Autor(es): Quadros, S.; Sousa, R.; Napier, V.; Raposo, V.
Revista: Água e Sustentabilidade Ambiental: Desafios e ação
Editor: APRH/APESB
Volume:
Boletim nº1.
Keywords: Água para consumo humano; Atividade agrícola; Indíce de suscetibilidade; Contaminação fecal; Nitrato
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A Review on Cement-Based Materials and Practices for Rehabilitation, Retrofitting, and Strengthening of Hydraulic Structures
This paper aims at compiling the most relevant information concerning the use of cement-based mortars and concretes in the rehabilitation, retrofitting, and strengthening of hydraulic structures, namely concrete dams. The most important properties of cementbased mortars and concretes as repair materials are addressed, with a special focus on its compatibility with the concrete substrate. After a brief allusion to generic preparatory works, some of the most common practices are described. The main topics are mortar and concrete toppings, i.e., patches and overlays and thickening of the dam section. Among overlays, shotcrete and underwater works are addressed in detail. Littlerock, Oberems, and Storfinnforsen dam interventions are briefly described as successful rehabilitations involving the shotcrete method, whereas the Albbruck-Dogern dam intervention is given as an example of effective underwater repair works. As for dam section modifications, Kölnbrein, Olef, and Sasanagare dams are presented as conventional mass concrete placements within rehabilitation operations, while Les Toules, Gibraltar, Santa Cruz, and Littlerock dams are references for roller compacted concrete strengthening.
Ano: 2022
Autor(es): Silva, J.; Serra, C.
Revista: Practice Periodical on Structural Design and Construction
Editor: ASCE
Volume:
Volume 27 / Issue 3.
Keywords: Concrete; Mortar; Strengthening; Retroffiting; Rehabilitation; Concrete dams
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A treatment reliability-based method for supporting infrastructure asset management of wastewater treatment plants
A simple and consolidated reliability-based method widely used to unveil the real reliability and stability of wastewater treatment plants (WWTPs) is herein proposed to trigger decision making on operational improvements and asset management for maintaining or improving treatment effectiveness, reliability, and efficiency.
Ano: 2022
Número Páginas:
13 pp..
Autor(es): Silva, C.; Rosa, M. J.
Revista: Water
Editor: MDPI
Volume:
14.
Keywords: Infrastructure asset management; Activated sludge systems; Wastewater treatment plants; Reliability
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Accessing Synergies and Opportunities between Nature-Based Solutions and Urban Drainage Systems.
Urban drainage systems face intrinsic constraints related to the deterioration of infrastructure, the interaction between systems, and increasing requirements and stresses that lower the quality of provided services. Furthermore, climate change and the need for the efficient use of resources are providing additional pressures that cannot be addressed solely with
Ano: 2022
Número Páginas:
19 pp..
Autor(es): Ramísio, P.; Brito, R.; Beceiro, P.
Revista: Sustainability
Editor: MDPI
Volume:
14.
Keywords: Floods; Diffuse pollution; Urban runoff; Social co-benefits; Urban environment; Urban pollution
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