Infrastructures, Volume 7, Issue 2 (February 2022) – 15 articles

Current buildings are responsible for the highest energy consumption, exceeding polluting sectors such as industry and transports. In Portugal, a large part of the building stock was built in the 1970s and 1980s, but buildings dated from the 1960s and 1970s are the ones with the most anomalies and worst quality of construction and, therefore, worst energy performance. The renovation of those buildings can represent an excellent opportunity to correct and improve their energy deficiency and, with that, to promote a more sustainable building stock. The ETICS system is the most used for the renovation of buildings in Portugal due to its lower cost, quick application and thermal efficiency, but it doesn’t solve other problems that may exist, such as structural safety and interior organization of the existing building. The application of prefabricated systems in the envelope has proved to be successful in improving energy efficiency, allowing new volumes and extra areas while contributing to the structural resilience of existing buildings. This paper aims to describe the current situation of the buildings renovation in Portugal and to discuss the potential of innovative envelope retrofitting solutions, using natural materials like timber, and is more concerned with the problems of existing buildings and the need for comfort and space for the occupants. Full article

In the past few years, there has been an increasing societal and industrial demand for the reliable assessment and design of structural systems with service-life criteria of at least several decades. The life cycle characterisation of engineering structures in terms of an anticipated service life remains a significant aspect of sustainability in the construction industry. This requires special attention to the definition of structural performance under various actions, and to the implemented engineering materials and methods as well as to the inverse identification and monitoring of structural conditions. Subsequently, the focus remains on the development of a holistic performance-based design approach for new and existing structures and infrastructures. This paper presents the fundamental reliability concepts of performance-based design, with a focus on lifetime assessment. Case studies from actual structural components’ design are used to verify the proposed methodology and indicate the significance of quality assurance in the lifetime assessment of engineering structures. We also confirmed that reliability and quality assurance criteria are strongly connected. Therefore, a methodology for quality-based service life assessment is presented and elaborated in the case studies. Full article

Today, automobile dependency constantly causes traffic congestion, delays, reduced access, increased fuel and energy consumption, and environmental emissions. Automobile dependency has caused many direct and indirect transportation problems that may influence our life. Urban planners and transportation engineers seek to improve transport networks considering social issues. One of the most successful solutions for advocating sustainable transport is transit-oriented development (TOD). Another solution that planners encourage to use is designing the roadways based on a complete street approach, which is a system that provides safe, convenient, and comfortable travel and increases accessibility for users of all ages regardless of their transport modes. The present study employed the saturated roads that have heavy traffic most of the time and public transport e-ticket data to investigate the potential complete streets in Qazvin. An online questionnaire was developed using the Analytic Hierarchy Process (AHP) method based on the TOD and the complete street framework to investigate the essential criteria for redesigning the network based on the active transport approach. Thus, after analyzing the six criteria (density, diversity, distance, accessibility, demand management, and design) and eight sub-criteria (pedestrian flow, pedestrian density, connectivity, safety, bike route, bus route, road width, and urban tree canopy index), the proposed active transport network emerged and results show that five high priority streets were identified to be considered as a solution. Full article

This study describes the results of a series of 2D finite element method (FEM) numerical models of 6 m high back-to-back reinforced soil walls using the geotechnical software PLAXIS. These structures are used to support embankments, especially for bridge abutment approaches. The quantitative influence of problem geometry, strip pre-tensioning, strip type, and surcharging on horizontal displacements, development of soil shear and plastic zones, lateral earth pressure, and reinforcement loads is presented. The numerical results demonstrate how this type of reinforced soil walls perform jointly at a certain distance of interaction between the two opposite walls. The walls of the two opposing sides clearly interact with each other when they are close enough and with an overlapping reinforcement layout. Pre-tensioning load can contribute to achieving vertical wall-facing alignment at the end of construction. Using perforated/holed strips, the tensile loads at the end of construction were reduced by about 30% due to the improved polymeric–soil interface strength and stiffness. Full article

The geography over which maritime transportation operates is unique, combining physical, strategic, and commercial imperatives. Physical issues are stable across time, but strategic, especially commercial, considerations continually shift with the ebb and flow of the globalization process. Contextually, the distance that isolates different locations in many cases plays a vital function in these interactions. Distance is the primary element that affects the values of interaction intensities. In fact, the issue is how the intensities were reduced with distance since this reduction is generally not linear. In this regard, this article intends to pursue the issues of the shape and parameters of the distance–decay functions based on the travel time value between islands. In this regard, almost all the Azores Islands were used as a case study. The study results show that the distance–decay functions established the unique dominance of Faial Island, Pico Island, and São Jorge Island, all in the Azores central group; in addition, there was an increase in the number of passengers in those. Moreover, the dominant position is the central islands, and their coexistence with others in the environment makes them more accessible than other islands, showing Terceira Island as a potential maritime passengers’ hub in the Azores. So, with this study, it becomes clear which are the main accessibility issues within the Azores archipelago as well as efficiency should be promoted through the design of policies in maritime passengers’ transportation. Full article

Mega-projects, particularly for the development of infrastructure, are being undertaken increasingly in many developing countries. Mega-projects are highly complex and involve significant construction activities. However, mega-projects in Africa face critical challenges of delay and cost overruns because of their nature and the complexities involved. Therefore, using the context of mega-projects in South Africa and stakeholders’ perceptions, the factors that influence construction, and strategies that would alleviate the challenges and improve construction management at sites were examined in this study. Factor analysis and ordinal regression modelling were used to analyse data obtained from a survey conducted among stakeholders. Findings suggested that five principal components and associated factors, including stakeholders, plant and machinery, productivity, workforce and materials, significantly affect construction during mega-projects. Further, eight strategies that are aligned to stakeholder engagement, plants and machinery, productivity, human resources and materials are likely to improve construction management at sites of mega-projects in South Africa. The four most important strategies include making the availability of competent personnel for plant and machinery operation and maintenance, effective supervision and monitoring, the adoption of appropriate stakeholder engagement methods and ensuring transparent and effective engagement, and the implementation of an advanced and effective communication system. Further strategies, such as the identification of stakeholders and common goals and procurement and use of advanced and quality plant and machinery, including the use of robotics and automation, could improve construction at sites. Similarly, strategies such as ensuring availability of adequate and quality material, and management of the site for effective accessibility and operation, although likely to have lesser influence, could also improve construction at sites of mega-projects. Full article

Speeding is one of the risky behaviors which results in accident involvement causing fatalities and severe injuries. This paper aimed to identify the significant socio-economic characteristics of drivers concerning their speeding behavior and crash involvement. A questionnaire was designed consisting of driver’s demographic features, involvement in an accident, penalty on speed violations, and statements on speeding behavior in terms of exceeding the speed limits by 10 km/h or more on roads with different speed limits of 60, 80, 100, and 120 km/h per standard operating speeds on various road types in Pakistan. This survey was conducted in Lahore city and a total of 551 usable samples were obtained. A latent variable of drivers’ speeding behavior was introduced; factor loadings were estimated, and an observed variable of drivers’ crash experience was defined as the drivers’ crash involvement. Ordered regression analysis using the probit function was conducted on speeding behavior and crash involvement. The ordinal analysis revealed that the drivers’ age, gender, marital status, employment, vehicle engine size, type of vehicle they drive, and driving frequency per day are good predictors of speeding behavior. Similarly, male drivers’ age, vehicle engine size, and type of vehicle they drive were significant predictors of their likelihood to be involved in an accident. The young, single, and male drivers and drivers of cars with an engine capacity above 1.5 L were more likely to speed and be involved in crashes. These findings provide a clear understanding of a specific group of drivers who have a higher probability of speeding and crash involvement. There is a need to focus on specific demographic factors in the formulation of traffic safety policies and managing speedy drivers’ behaviors. Full article

Landslide incidents frequently occur in the upper northern region of Thailand due to its topography, which is mostly mountainous with high slopes. In the past, when landslides happened in this area, they affected traffic accessibility for rescue and evacuation. For this reason, if the risk of landslides could be evaluated, it would help in the planning of preventive measures to mitigate the damage. This study was carried out to create and develop a risk estimation model using the artificial neural network (ANN) technique for landslides at the edge of the roadside, by collecting field data on past landslides in the study areas in Chiang Rai and Chiang Mai Provinces. A total of 9602 data points were collected. The variables for forecasting were: (1) land cover, (2) physiographic features, (3) slope angle, and (4) five-day cumulative rainfall. Two hidden layers were used to create the model. The number of nodes in the first and second hidden layers were five and one, respectively, which were derived from a total of 25 trials, and the highest accuracy achieved was 96.74%. When applying the model, a graph demonstrating the relationship between the landslide risk, rainfall, and the slopes of the road areas was obtained. The results show that high slopes result in more landslides than low slopes, and that rainfall is a major trigger for landslides on roads. The outcomes of the study could be used to create risk maps and provide information for developing warnings for high-slope mountain roads in the upper northern region of Thailand. Full article

Structural health monitoring of highway bridges is a vital but currently challenging aspect of infrastructure engineering due to the number of sensors required, power requirements, and harsh environmental conditions. The purpose of this study is to develop a structural health monitoring system using fiber optic sensors based on fiber Bragg gratings that addresses these issues and is field deployable. Prototype systems were installed on two steel girder bridges. The first bridge used sensors adhered to the web and flange. The second bridge used a flange-only array of mechanically mounted sensors. The results demonstrated the accuracy of the fiber Bragg grating sensors and indicated that fewer multiplexed fiber optic cables and loosely routed cables were needed to maintain signal integrity. Adhered sensors were prone to lose their bond due to the curing conditions in the field. The findings suggest that the proposed system may be best used in a hybrid deployment, where a diagnostic field test with conventional sensors is used to determine the baseline bridge response and fiber optic sensors are periodically installed for short-term monitoring. Full article

The quantitative determination of the current load carrying capability of already loaded structural elements and the possibility to detect proper indices that could be considered as signals for timely warning that the load carrying capacity is exhausted is the subject of this study. More specifically, it aims to explore the possibility of detecting signals that can be considered as indices warning about upcoming fracture and then to compare quantitatively such signals provided by different techniques. The novelty of the present study lies exactly in this quantitative comparison of the pre-failure signals provided by various sensing techniques and various methods of analysis of the experimental data. To achieve this target, advantage is taken of data concerning the acoustic and electrical activities produced while marble specimens are subjected to mechanical loading. The respective signals are detected and recorded by means of the acoustic emissions technique and that of the pressure stimulated currents. The signals detected by the acoustic emissions technique are analyzed in terms of three formulations, i.e., the b-value, the F-function and the parameters variance κ₁, entropy S and entropy under time reversal S_ according to the natural time analysis. The signals detected by the pressure stimulated currents technique are analyzed by means of the intensity of the electric current recorded. The study indicates that all quantities considered provide promising pre-failure indicators. Furthermore, when the specimen is subjected to near-to-failure load levels, the temporal evolution of three of the quantities studied (b-value, F-function, pressure stimulated currents) is governed by a specific power law. The onset of validity of this law designates some differentiation of the damage mechanisms activated. Quantitative differences are observed between the time instants at which this power law starts dictating the evolution of the above parameters, indicating the imperative need for further investigation, despite the quite encouraging results of the present study. Full article

On 6 April 2021, a 200 m-long under-construction prestressed concrete bridge failed in the Chitwan District in central Nepal. Two of the four bridge spans collapsed without any notable evidence of dynamic force application. Under-construction bridge failures are sometimes reported and can have a significant impact on the future construction adjustments. Thus, a detailed study of failure mechanisms will be insightful for the structural engineering community. Aiming to document the failure modes and exemplify lessons for improvement, this paper reports the detailed component level failure mechanisms of the bridge using visual inspection, site measurements, finite element modeling, and some forms of non-destructive testing. The chronological failure mechanisms are presented based on the field evidence and juxtaposed with the results of analytical modeling. The sum of findings highlights that the dead load failure, triggered by the settlement of falseworks, is the most critically governing factor that initiated and aggravated the damage scenario. Full article

The behavior of a reinforced concrete building, seismically isolated with high damping rubber bearing (HDRB) and sliding devices (SD), observed during the most important events of the seismic sequence that struck central Italy from August 2016 to January 2017, is analyzed. Due to the epicenter distances, all the events had light effects at the site, thus the isolation system was not always put into action. A previous very low energy earthquake and the ambient vibration analysis are used for comparison. The study of the isolation system response is first carried out and the variability of the resonance frequencies with the input energy at the site is pointed out. These frequencies are quite close to those of the superstructure considered as fixed base. Small cracks were observed after the sequence in some partition walls of the building. The analysis of the superstructure was performed by means of a finite element model, assuming a non-linear model for the isolators, based on previous experimental data. The importance of a suitable decoupling between the superstructure and the ground and the contribution of the sliding devices under low energy earthquake is pointed out. Full article

The development of indexes for human development and environmental sustainability issues are an emerging topic in the current literature. However, the literature has put less emphasis on municipal indexes, which is the focus of this research. In this paper, we considered municipal environmental management as the adoption of environmental activities and the development of infrastructural and technical capacities in municipalities. This article aims to create a sustainable human development index with municipal data from the state of São Paulo in Brazil. Using information from the Municipal Human Development Index (IDHm) and the GreenBlue Municipal Program (PMVA), we applied the data envelopment analysis (DEA) technique to connect human development and environmental sustainability in 645 Brazilian municipalities. Our findings show that regions with higher human development present better DEA scores on the Sustainable Human Development Index. In contrast, regions with a low or a middle level of human development do not present significant change considering both dimensions. Moreover, our findings reveal that PMVA certification has a different and statistically significant impact on the DEA score considering certified, qualified, or not qualified regions. We found similar results for urbanized and service-oriented municipalities. Our indicator is an essential and straightforward tool for regional policymakers, helping to allocate resources and to find human development and environmental sustainability benchmarks among developing regions. Full article

Aviation is a highly inter-connected system. This means that a problem in one area may cause effects in other countries or parts of the Air Transport System (ATS). Examples range from local air traffic disruptions to the 2010 volcanic ash crisis. Agility, like resilience, refers to the ability to cope with dynamics and complexity in a flexible manner, by adjusting and adapting performance and the organization of work to fit changing demands. The aim of this work is to help ATS organizations with increasing their agility in the face of crises and challenges. To this end, this article presents the Agile Response Capability (ARC) guidance material. ARC was developed from a literature study and a number of case studies that combined past event analysis, interviews, focus groups, workshops, questionnaires, and exercise observation methodologies. ARC aims to help aviation organizations to set up, run, and evaluate exercises promoting agility to handle disturbances and crises, and to enable structured pro-active and retrospective analysis of scenarios and actual events. The elements and steps of the ARC approach are illustrated and exemplified with data from three case studies. The ARC methodology facilitates more agile and resilient ways of responding to the fundamental and novel surprises that have become almost commonplace in the past decade, and are likely to continue to do so. Full article