https://hdl.handle.net/10216/156 Wed, 05 Aug 2026 05:27:35 GMT 2026-08-05T05:27:35Z https://hdl.handle.net/10216/175749 Title: Algorithmic workflow for digitising inspection data in railway tunnel maintenance Abstract: Purpose This study addresses the lack of structured, data-driven approaches to infrastructure asset management, demonstrating how integrating building information modelling (BIM) and digital twin methodologies can enhance the maintenance and lifecycle management of railway tunnels.Design/methodology/approach A structured data-to-BIM workflow was co-developed with Infraestruturas de Portugal (IP), using inspection and monitoring data from 79 railway tunnels. The workflow includes automated data acquisition and systematisation, algorithmic generation of structured, data-rich BIM models, and a centralised digital twin platform for lifecycle monitoring.Findings Implementation enabled real-time data manipulation, predictive maintenance and improved decision-making. Key outputs include standardised data exchange protocols, product data templates, BIM object classes for tunnel components and digital twinning algorithms. Benefits observed include improved collaboration, automatic anomaly detection and enhanced visualisation of tunnel condition.Research limitations/implications Further research is needed to improve the algorithm's performance, minimise manual interventions and validate the workflow's scalability across diverse asset typologies and operational contexts.Originality/value The research presents a framework for integrating digital twins into infrastructure asset management, demonstrating the operational value of computational methods in transforming conventional maintenance and lifecycle management workflows and supporting data-driven decision-making. Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/10216/175749 2026-01-01T00:00:00Z https://hdl.handle.net/10216/175639 Title: Forecasting hourly discharge from Crestuma-Lever dam, Portugal Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/10216/175639 2026-01-01T00:00:00Z https://hdl.handle.net/10216/175388 Title: Classificação automática de tarefas de mapas de quantidades e trabalhos para a agilização do processo Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/10216/175388 2026-01-01T00:00:00Z https://hdl.handle.net/10216/174413 Title: Enhanced key performance indicators for energy performance contracts: A proposal for integrating indoor environmental quality evaluation Abstract: The building sector is a major contributor to energy consumption and greenhouse gas emissions in the European Union. In milder-climate regions, renovation programmes often face additional constraints linked to low baseline energy demand and socio-economic vulnerability. Energy Performance Contracts (EPCs) are a key mechanism for financing retrofits, yet conventional EPC evaluation remains largely savings-driven, which can be insufficient to represent delivered benefits, predominantly where energy use is low and behaviourally constrained. This study proposes an enhanced EPC evaluation framework that integrates Indoor Environmental Quality (IEQ) with energy performance to assess both Return on Investment and Return on Mission. The framework retains energy indicators as essential contractual compliance measures, while introducing a standardised, threshold-based indicator set to evaluate IEQ performance consistently across parameters and spaces. Beyond time of non-compliance, the proposed indicators capture the duration, magnitude, and intensity of noncompliance, complemented by metrics on variability and extreme events to support diagnosis and accountability. The framework is designed for implementation within a Digital Twin environment, enabling continuous monitoring, adaptive threshold alerts, and automated performance visualisation without increasing contractual complexity. Validation in a Portuguese social housing neighbourhood demonstrates that severity-sensitive indicators capture improvements that may be overlooked by time-based indicators, supporting fairer verification of retrofit deliverables. Overall, the proposed approach strengthens EPC appraisal by improving transparency in performance reporting under dynamic operating conditions and aligning contractual evaluation with occupant-centred outcomes, thereby supporting the evolution of EPCs in milder-climate regions toward more mission-driven models that better couple energy efficiency objectives with comfort and well-being. Sun, 24 May 2026 00:00:00 GMT https://hdl.handle.net/10216/174413 2026-05-24T00:00:00Z https://hdl.handle.net/10216/175386 Title: Uma breve história da interoperabilidade na construção Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/10216/175386 2026-01-01T00:00:00Z https://hdl.handle.net/10216/133080 Title: Valorization of Fine-Grain Construction and Demolition (C&D) Waste in Geosynthetic Reinforced Structures Abstract: Current environmental awareness compels all citizens to reduce the production of waste and use recycled materials. Recycled materials coming from construction and demolition (C&D) waste are progressively being used in civil engineering applications, such as base and sub-base layers of transport infrastructures and concrete production. However the fine grain fraction of C&D recycled materials is not considered appropriate for those applications, being frequently landfilled instead of reused. This paper assesses the possibility of using fine grain C&D recycled materials as backfilling of geosynthetic reinforced structures (embankments and retaining walls), replacing the soils typically used in the construction of these structures. The study has involved physical, mechanical and environmental characterization of C&D recycled materials, characterization of the interfaces between the fill material and three geosynthetics, through direct shear and pullout tests, and the evaluation of the potential damages induced by the C&D recycled materials on the short-term tensile behaviour of the geosynthetics. The results presented in this paper support the suitability of using C&D recycled materials in the construction of geosynthetic reinforced structures and thus diminishing our carbon footprint, through the reduction of the environmental impacts induced by C&D waste landfilling and by the extraction of natural aggregates. Mon, 01 Jan 2018 00:00:00 GMT https://hdl.handle.net/10216/133080 2018-01-01T00:00:00Z https://hdl.handle.net/10216/101983 Title: Damage induced by recycled Construction and Demolition Wastes on the short-term tensile behaviour of two geosynthetics Abstract: Geosynthetics have been used as a reinforcement material in roadways and railways construction. Notwithstanding, one of the main questions of using is their durability. The damage caused by the mechanical actions during installation and the chemical and biological degradation are important issues to consider in the physical, mechanical and hydraulic behaviour of geosynthetics. The change in their properties induced by these degradation processes can compromise the performance of these materials. In order to study the chemical and environmental degradation induced by a recycled Construction and Demolition Waste (C&DW) on the short-term tensile behaviour of two geosynthetics (a uniaxial HDPE geogrid and a nonwoven PP geotextile reinforced with PET yarns) used commonly as reinforcement material, a damage trial embankment (2. m. ×. 3. m in plan) was constructed. This paper presents and discusses the effects produced by the recycled C&DW on geosynthetic samples exhumed after 6. months of the embankment construction. The constituents and the leaching behaviour of the recycled C&DW are presented. Wide width tensile tests were performed on exhumed and intact (as-received) geosynthetics and their tensile behaviour is compared. Scanning electron microscope (SEM) images of intact and exhumed specimens are also presented. As expected the degradation induced by the recycled C&DW after 6. months of exposure is not very expressive. On the HDPE geogrid the recycled C&DW induced a small decrease on the tensile strength and the reduction of the tensile stiffness modulus. The geocomposite experienced some reduction on the tensile strength (16% on average) but the effects on tensile stiffness and shape of the load-strain curves were not significant. (c) 2015 Elsevier Ltd. Thu, 01 Jan 2015 00:00:00 GMT https://hdl.handle.net/10216/101983 2015-01-01T00:00:00Z https://hdl.handle.net/10216/175336 Title: Enhancing the mechanical performance of mixed recycled aggregates for unbound pavement layers Abstract: The use of recycled aggregates in road pavements can markedly contribute to more sustainable infrastructures, minimising the extraction of virgin aggregates and using secondary materials that would otherwise be discharged into the environment with negative impacts. In Portugal, as in most Southern European countries, most of the recycled aggregates coming from construction and demolition waste are mixed or non-selected recycled aggregates, containing concrete and mortars, natural aggregates, masonries, among others. These materials are considered as low-quality recycled aggregates, due to poor mechanical properties, namely, their resistance to fragmentation and to wear, and as a result their use in roadway pavement layers is frequently unfeasible. This paper presents the results of a laboratory study on mixtures of a non-selected recycled aggregate with natural and tyre rubber aggregates, with a primary focus on resistance to fragmentation. The study also discusses the fragmentation resistance across different aggregate sizes. The results show that to achieve a meaningful improvement in the fragmentation resistance of the recycled aggregate, it should be blended with very high-quality all-in-aggregates. The addition of tyre-derived aggregate (TDA) to recycled and natural aggregates markedly improves fragmentation resistance; however, the concentration of zinc in the TDA leachate exceeds the regulatory limit. Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/10216/175336 2026-01-01T00:00:00Z https://hdl.handle.net/10216/129634 Title: Towards constant mesh stiffness helical gears: The influence of integer overlap ratios Abstract: This work presents the development and dynamic analysis of Constant Mesh Stiffness Gears. First, a study of the contact length variation between gears is conducted since it has great influence on the gear mesh stiffness. Following that, an algorithm capable of generating Constant Mesh Stiffness Gears (CMSGears) was developed while considering the gear's safety factors and mesh efficiency. The dynamic performance of these gears was evaluated resorting to a single degree of freedom dynamic model which considered teeth contact loss. The CMSGears created respect the gear design principles and both the gear safety factors and gear mesh efficiency were successfully taken into account. With regard to the dynamic behavior of these gears, they ended up revealing great potential in the reduction of noise, vibration and dynamic overload. Tue, 01 Jan 2019 00:00:00 GMT https://hdl.handle.net/10216/129634 2019-01-01T00:00:00Z https://hdl.handle.net/10216/163462 Title: Hybrid Polymer Gear Concepts to Improve Thermal Behavior Abstract: A drawback of polymer materials is their low thermal conductivity which affects the operating temperature of polymer gears. The mechanical properties of a polymer gear are critically dependent on the maximum operating temperature. In order to improve thermal behavior of polymer gears, a hybrid polymer gear concept is suggested which consists of a polymer gear tooth with a metallic insert to promote heat evacuation from the meshing surface. The material selection based on finite element method (FEM) simulations showed that an aluminum insert performed better than copper and steel for a hybrid polymer gear. The results show that an aluminum insert increases the mass by 9% in comparison with a standard polymer gear but it decreases the maximum operating temperature by 28%. Insert geometries of different complexity were studied and their influence on operating temperature assessed. Tue, 01 Jan 2019 00:00:00 GMT https://hdl.handle.net/10216/163462 2019-01-01T00:00:00Z https://hdl.handle.net/10216/175101 Title: Reclaiming Gold from Integrated Circuits Waste via a Sustainable Physic-Hydrometallurgical Approach Sat, 18 Jul 2026 00:00:00 GMT https://hdl.handle.net/10216/175101 2026-07-18T00:00:00Z https://hdl.handle.net/10216/175102 Title: Historical trajectories of the soundscape of urban parks: a comparison between São Paulo (Brazil) and Porto (Portugal) Fri, 30 Jan 2026 00:00:00 GMT https://hdl.handle.net/10216/175102 2026-01-30T00:00:00Z https://hdl.handle.net/10216/174973 Title: A Case Study of Work Based Learning (WBL) using E-Learning Wed, 01 Sep 2010 00:00:00 GMT https://hdl.handle.net/10216/174973 2010-09-01T00:00:00Z https://hdl.handle.net/10216/171250 Title: Environmental and Nutritional Sustainability of Diets: Exploring Food Consumption Patterns Between Different Sustainability Groups Abstract: Food sustainability is a vital global challenge, as dietary choices affect both human health and the environment. This study evaluates Portuguese dietary patterns' environmental and nutritional sustainability dimensions using data from the National Food, Nutrition, and Physical Activity Survey (IAN-AF) 2015-2016. Environmental indicators (carbon footprint, water footprint, and land use) and a nutritional quality index (NRD9.3) were analysed. Sustainability scores were calculated based on deviations from population medians, with the environmental score estimated from a weighted mean of the three indicators. A quadrant analysis classified individuals into four sustainability segments: better environmental and better nutritional scores (reference group); worse environmental and worse nutritional scores; worse environmental and better nutritional scores; and better environmental and worse nutritional scores. The reference group, with higher plant-based food consumption, had the lowest environmental impacts, 33% lower carbon footprint, 36% lower water footprint, and 50% lower land use, while exhibiting 87% better nutritional quality. In contrast, the worse environmental and worse nutritional scores group, with a diet rich in red and processed meats, sweets, and alcohol, showed higher environmental impacts and poorer nutritional quality. The group with worse environmental and better nutritional scores favored dairy and seafood, whereas the group with better environmental and worse nutritional scores had higher intakes of white meat, sweets, and alcohol. Sociodemographic factors, including sex, age, and education, show to influence the sustainability dimensions. These findings highlight the need for tailored dietary strategies that consider differing environmental and nutritional profiles, supporting more effective and practical public health interventions. Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/10216/171250 2026-01-01T00:00:00Z https://hdl.handle.net/10216/174875 Title: On the Structural Distortion Induced by the Inverse Box-Cox Transformation Fri, 10 Jul 2026 00:00:00 GMT https://hdl.handle.net/10216/174875 2026-07-10T00:00:00Z https://hdl.handle.net/10216/174864 Title: Development of a modelling framework for running safety analysis of a heavy-haul freight vehicle crossing a bridge under different loading conditions Abstract: Evaluation of train running safety for freight and heavy-haul railway vehicles is a poorly addressed topic in the literature, despite their distinct dynamic behaviour and track conditions compared with passenger and high-speed railways. For this purpose, a framework for the development of a three-dimensional numerical analysis of train running safety crossing a bridge using a vehicle-structure interaction methodology is presented. Numerical models of the railway bridge were developed and calibrated, and multibody models of the heavy-haul vehicles were created and optimised based on modal data. Structure and vehicle dynamic responses were obtained using the dynamic interaction models that consider nonlinear wheel-rail contact models. Assessment of structural and train running safety was performed for multiple train speeds for both loaded and unloaded vehicles using different degrees of rail geometric irregularities based on the Federal Railroad Administration's power spectral density functions. The case study is a 550-metre-long railway bridge composed of 22 simply supported steel-concrete composite spans, crossed by heavy-haul vehicles of the gondola-type wagon with 375 kN axle loads. The safety of the bridge was assessed in terms of structural responses according to European codes, while the running safety of the vehicle was evaluated through indirect running safety indices as well as direct derailment coefficients based on vertical and lateral wheel-rail contact forces and more advanced criteria. It was found that in regular operational conditions, all indices are well below recommended limit values for loaded vehicles, whereas the unloaded vehicles presented a more unstable dynamic behaviour. Thu, 09 Jul 2026 00:00:00 GMT https://hdl.handle.net/10216/174864 2026-07-09T00:00:00Z https://hdl.handle.net/10216/174791 Title: Transport disadvantage and accessibility gaps: Addressing equity in Porto's metropolitan public transport system Tue, 01 Dec 2026 00:00:00 GMT https://hdl.handle.net/10216/174791 2026-12-01T00:00:00Z https://hdl.handle.net/10216/174752 Title: Intermodal versus monomodal travellers: Evidence from a comparative study in Porto Tue, 15 Sep 2026 00:00:00 GMT https://hdl.handle.net/10216/174752 2026-09-15T00:00:00Z https://hdl.handle.net/10216/166661 Title: Assessment of integrated rail and bus transport network design: Equity and efficiency perspectives Abstract: Recognizing the vital role of public transport (PuT) in accessibility, inclusivity, and quality of life, its planning must balance efficiency with equitable service coverage. This study examines PuT network design, integrating rail and bus services while incorporating equity considerations for a more efficient and socially equitable system. Despite extensive research on PuT network design (PTND), balancing these objectives remains a key challenge in transit planning. This paper presents a methodological framework that integrates PTND with Data Envelopment Analysis (DEA) to design and evaluate multiple PTND scenarios. These scenarios are assessed using equity-based perspectives: potential demand (PD), adjusted demand (AD), and transport needs (TN). The approach identifies efficient designs that maximize service coverage and social equity, addressing varying population demands and needs. The methodology is demonstrated through a case study in the metropolitan area of Porto (AMP), offering policymakers insights into PuT equity implications for the infrastructure planning and decision-making process. Two output-oriented DEA models were developed: one using service coverage adequacy (SCA) as output and another incorporating both SCA and the GINI coefficient (equity) to assess the impact of different equity perspectives on system efficiency. Results indicate that network designs based on AD performed better with higher efficiency scores than PD and TN, suggesting that AD better captures PuT demand needs and supports equitable service distribution. The findings emphasize the need to integrate population equity perspectives and multimodal transport to create more balanced and efficient PuT systems, ensuring fair access to mobility for diverse populations in the region. Wed, 01 Jan 2025 00:00:00 GMT https://hdl.handle.net/10216/166661 2025-01-01T00:00:00Z https://hdl.handle.net/10216/82505 Title: Metodologia para avaliação dos fatores condicionantes da velocidade em regime livre em ambiente periurbano Abstract: This paper presents a new methodology for the evaluation of the effects of posted speed limit, geometric and environmental characteristics on free-flow speed in transition zones, through a macroscopic analysis. A vehicle travels under free-flow conditions if its chosen speed is not affected by the presence of the vehicle ahead. In this sense, the free-flow speed reflects the driver's response to road geometric and environmental characteristics. In the first stage of the proposed methodology, new macroscopic variables reflecting the characteristics of transition zones are created through the use of multivariate data analysis techniques, namely analysis of clusters and principal component analysis. In the second stage, a regression analysis is performed in order to compare the effects of different variables on the adopted free-flow speed. This methodology is then tested for a set of 27 sites located in Portuguese two-lane highways, where drivers' speed, the existence of posted speed limit and some geometric and environmental microscopic characteristics were collected. Description: Neste artigo, apresenta-se uma metodologia para a avaliação macroscópica da influência das características geométricas e ambientais e da sinalização de velocidade limite legal na velocidade em regime livre praticada pelos condutores em zonas periurbanas ou de transição. Um condutor circula em regime livre quando a sua escolha de velocidade não é condicionada pela presença do veículo precedente. Assim, a velocidade adotada reflete a sua resposta face às características da estrada e do ambiente envolvente. A metodologia consiste na utilização de métodos estatísticos de análise de dados multivariados, nomeadamente de classificação e de análise em componentes principais, para a definição de variáveis macroscópicas caracterizadoras das zonas periurbanas, sobre as quais é depois efetuada uma análise de regressão que permite a avaliação dos impactos das diferentes variáveis na velocidade em regime livre. A metodologia proposta é aplicada a um conjunto de 27 locais pertencentes a estradas de duas vias situadas em Portugal, onde foram observadas as velocidades praticadas, a existência de sinalização de limite legal de velocidade e diversas variáveis microscópicas caracterizadoras da geometria e do ambiente. Sun, 01 Jan 2012 00:00:00 GMT https://hdl.handle.net/10216/82505 2012-01-01T00:00:00Z