Pub Date : 2023-12-04DOI: 10.3390/infrastructures8120173
G. M. Guzmán-Acevedo, J. A. Quintana-Rodriguez, J. R. Gaxiola-Camacho, G. E. Vazquez-Becerra, Vanessa Torres-Moreno, J. G. Monjardin-Quevedo
In recent years, Interferometric Synthetic Aperture Radar (InSAR) technology has been able to determine the semi-static behavior of bridges. However, most of the research about the use of InSAR in the monitoring of bridges has been applied only in deterministic assessments of their performance. Therefore, in the current manuscript, the Usumacinta Bridge, located in Mexico, was evaluated based on a probabilistic methodology to define structural reliability using images from Sentinel-1. In addition, a controlled experiment was developed using a corner reflector (CR) to evaluate the capabilities of InSAR for determining vertical displacements. In the trial, the CR was designed, oriented, and implemented, finding discrepancies concerning leveling of less than 2 mm. On the other hand, the case of the alternative probabilistic approach integrates the reliability of structures theory and probability density functions (PDFs) of displacements obtained via InSAR technology. In summary, the proposed study focused on the analysis of two years of vertical displacements and monthly velocities; then, implementing the alternative probabilistic approach, the reliability index (β) and probability of risk (PR) of the bridge were extracted, respectively. Based on the results of the experimental part of the paper, the displacements indicated maximum and minimum values of reliability index of 8.1 and 3.4, respectively. Within this context, the mean and standard deviation obtained were 5.9 and 1.4, respectively. On the other hand, the monthly velocities showed a maximum probability of risk of 2.61%, minimum value of 1.5 × 10−5%, mean of 0.4%, and standard deviation of 0.8%. Hence, the above-documented results indicate that the Usumacinta Bridge did not suffer any damage during its overloading condition period.
{"title":"The Structural Reliability of the Usumacinta Bridge Using InSAR Time Series of Semi-Static Displacements","authors":"G. M. Guzmán-Acevedo, J. A. Quintana-Rodriguez, J. R. Gaxiola-Camacho, G. E. Vazquez-Becerra, Vanessa Torres-Moreno, J. G. Monjardin-Quevedo","doi":"10.3390/infrastructures8120173","DOIUrl":"https://doi.org/10.3390/infrastructures8120173","url":null,"abstract":"In recent years, Interferometric Synthetic Aperture Radar (InSAR) technology has been able to determine the semi-static behavior of bridges. However, most of the research about the use of InSAR in the monitoring of bridges has been applied only in deterministic assessments of their performance. Therefore, in the current manuscript, the Usumacinta Bridge, located in Mexico, was evaluated based on a probabilistic methodology to define structural reliability using images from Sentinel-1. In addition, a controlled experiment was developed using a corner reflector (CR) to evaluate the capabilities of InSAR for determining vertical displacements. In the trial, the CR was designed, oriented, and implemented, finding discrepancies concerning leveling of less than 2 mm. On the other hand, the case of the alternative probabilistic approach integrates the reliability of structures theory and probability density functions (PDFs) of displacements obtained via InSAR technology. In summary, the proposed study focused on the analysis of two years of vertical displacements and monthly velocities; then, implementing the alternative probabilistic approach, the reliability index (β) and probability of risk (PR) of the bridge were extracted, respectively. Based on the results of the experimental part of the paper, the displacements indicated maximum and minimum values of reliability index of 8.1 and 3.4, respectively. Within this context, the mean and standard deviation obtained were 5.9 and 1.4, respectively. On the other hand, the monthly velocities showed a maximum probability of risk of 2.61%, minimum value of 1.5 × 10−5%, mean of 0.4%, and standard deviation of 0.8%. Hence, the above-documented results indicate that the Usumacinta Bridge did not suffer any damage during its overloading condition period.","PeriodicalId":13601,"journal":{"name":"Infrastructures","volume":"20 13","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138603514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.3390/infrastructures8120171
Rodrigo Joaquín Contreras, Ignacio Escuder-Bueno
Dams and reservoirs have always been of interest to human beings, playing a crucial role given the importance of securing water for sanitary use, irrigation, navigation, flood control and energy generation, among others. The main focus of this article is to perform a historical review of dam safety practices. For this purpose, the historical periods are divided into homogeneous periods in terms of dam safety paradigms and, following the narrative of this evolution, the paper considers the fundamentals of the two most important conceptual frameworks applied nowadays: the standard-based approach and the risk-informed one. As a matter of fact, after more than 90 years of experience in the application of dam safety assessment techniques and more than 50 years of recognising and studying the implications of human activity for the environment, today, the industry may have sufficient information and knowledge to take dam safety practice to another stage, being this the core of the discussion that follows the historical review.
{"title":"Dam Safety History and Practice: Is There Room for Improvement?","authors":"Rodrigo Joaquín Contreras, Ignacio Escuder-Bueno","doi":"10.3390/infrastructures8120171","DOIUrl":"https://doi.org/10.3390/infrastructures8120171","url":null,"abstract":"Dams and reservoirs have always been of interest to human beings, playing a crucial role given the importance of securing water for sanitary use, irrigation, navigation, flood control and energy generation, among others. The main focus of this article is to perform a historical review of dam safety practices. For this purpose, the historical periods are divided into homogeneous periods in terms of dam safety paradigms and, following the narrative of this evolution, the paper considers the fundamentals of the two most important conceptual frameworks applied nowadays: the standard-based approach and the risk-informed one. As a matter of fact, after more than 90 years of experience in the application of dam safety assessment techniques and more than 50 years of recognising and studying the implications of human activity for the environment, today, the industry may have sufficient information and knowledge to take dam safety practice to another stage, being this the core of the discussion that follows the historical review.","PeriodicalId":13601,"journal":{"name":"Infrastructures","volume":" 2","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138611199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-29DOI: 10.3390/infrastructures8120170
Tiago Tamagusko, Adelino Ferreira
Timely maintenance of road pavements is crucial to ensure optimal performance. The accurate prediction of trends in pavement defects enables more efficient allocation of funds, leading to a safer, higher-quality road network. This article systematically reviews machine learning (ML) models for predicting the international roughness index (IRI), specifically focusing on flexible pavements, offering a comprehensive synthesis of the state-of-the-art. The study’s objective was to assess the effectiveness of various ML techniques in predicting IRI for flexible pavements. Among the evaluated ML models, tree ensembles and boosted trees are identified as the most effective, particularly in managing data related to traffic, pavement structure, and climatic conditions, which are essential for training these models. Our analysis reveals that traffic data are present in 89% of the studies, while pavement structure and climatic factors are featured in 78%. However, maintenance and rehabilitation history appears less frequently, included in 33% of the studies. This research underscores the need for high-quality, standardized datasets, and highlights the importance of model interpretability and computational efficiency. Addressing data consistency, model interpretability, and replicability across studies are crucial for leveraging ML’s full potential in fine-tuning IRI predictions. Future research directions include developing more interpretable, computationally efficient, and less complex models to maximize the impact of this research field in road infrastructure management.
及时维护路面对确保最佳性能至关重要。对路面缺陷趋势的准确预测可以更有效地分配资金，从而实现更安全、更高质量的路网。本文系统地评述了预测国际粗糙度指数（IRI）的机器学习（ML）模型，尤其侧重于柔性路面，对最先进的技术进行了全面综合。研究的目的是评估各种 ML 技术在预测柔性路面 IRI 方面的有效性。在所评估的 ML 模型中，树集合和提升树被认为是最有效的，尤其是在管理与交通、路面结构和气候条件相关的数据方面，这些数据对于训练这些模型至关重要。我们的分析表明，89% 的研究涉及交通数据，78% 的研究涉及路面结构和气候因素。然而，养护和修复历史出现的频率较低，只有 33% 的研究包含这些内容。这项研究强调了对高质量、标准化数据集的需求，并突出了模型可解释性和计算效率的重要性。要充分发挥 ML 在微调 IRI 预测方面的潜力，解决数据一致性、模型可解释性和研究间可复制性问题至关重要。未来的研究方向包括开发可解释性更强、计算效率更高、复杂程度更低的模型，以最大限度地发挥这一研究领域在道路基础设施管理方面的影响。
{"title":"Machine Learning for Prediction of the International Roughness Index on Flexible Pavements: A Review, Challenges, and Future Directions","authors":"Tiago Tamagusko, Adelino Ferreira","doi":"10.3390/infrastructures8120170","DOIUrl":"https://doi.org/10.3390/infrastructures8120170","url":null,"abstract":"Timely maintenance of road pavements is crucial to ensure optimal performance. The accurate prediction of trends in pavement defects enables more efficient allocation of funds, leading to a safer, higher-quality road network. This article systematically reviews machine learning (ML) models for predicting the international roughness index (IRI), specifically focusing on flexible pavements, offering a comprehensive synthesis of the state-of-the-art. The study’s objective was to assess the effectiveness of various ML techniques in predicting IRI for flexible pavements. Among the evaluated ML models, tree ensembles and boosted trees are identified as the most effective, particularly in managing data related to traffic, pavement structure, and climatic conditions, which are essential for training these models. Our analysis reveals that traffic data are present in 89% of the studies, while pavement structure and climatic factors are featured in 78%. However, maintenance and rehabilitation history appears less frequently, included in 33% of the studies. This research underscores the need for high-quality, standardized datasets, and highlights the importance of model interpretability and computational efficiency. Addressing data consistency, model interpretability, and replicability across studies are crucial for leveraging ML’s full potential in fine-tuning IRI predictions. Future research directions include developing more interpretable, computationally efficient, and less complex models to maximize the impact of this research field in road infrastructure management.","PeriodicalId":13601,"journal":{"name":"Infrastructures","volume":"35 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139212511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-28DOI: 10.3390/infrastructures8120169
Jinxi Zhang, Weiqi Zhou, Dandan Cao, Jia Zhang
The generalized Maxwell (GM) constitutive model has been widely applied to characterize the viscoelastic properties of asphalt mixtures. The parameters (Prony series) of the GM are usually obtained via interconversion between a dynamic modulus and relaxation modulus, and they are then input to a finite element model (FEM) as viscoelastic parameters. However, the dynamic modulus obtained with the common loading mode only provides the compressive and tensile properties of materials. Whether the compression or tensile modulus can represent the shear properties of materials related to flow rutting is still open to discussion. Therefore, this study introduced a novel method that integrates the Kriging model into the genetic algorithm as a surrogate model to determine the viscoelastic parameters of an asphalt mixture in rutting research. Firstly, a wheel tracking test (WTT) for AC-13 was conducted to clarify the flow rutting development mechanism. Secondly, two sets of the AC-13 viscoelastic parameters obtained through the optimization method and the dynamic modulus were used as inputs into the FEM simulation of the WTT to compare the simulation results. Finally, a sensitivity analysis of viscoelastic parameters was performed to improve the efficiency of parameter optimization. The results indicating the viscoelastic parameters obtained by this method could precisely characterize the development law of flow rutting in asphalt mixtures.
{"title":"A Study on the Genetic Algorithm Optimization of an Asphalt Mixture’s Viscoelastic Parameters Based on a Wheel Tracking Test","authors":"Jinxi Zhang, Weiqi Zhou, Dandan Cao, Jia Zhang","doi":"10.3390/infrastructures8120169","DOIUrl":"https://doi.org/10.3390/infrastructures8120169","url":null,"abstract":"The generalized Maxwell (GM) constitutive model has been widely applied to characterize the viscoelastic properties of asphalt mixtures. The parameters (Prony series) of the GM are usually obtained via interconversion between a dynamic modulus and relaxation modulus, and they are then input to a finite element model (FEM) as viscoelastic parameters. However, the dynamic modulus obtained with the common loading mode only provides the compressive and tensile properties of materials. Whether the compression or tensile modulus can represent the shear properties of materials related to flow rutting is still open to discussion. Therefore, this study introduced a novel method that integrates the Kriging model into the genetic algorithm as a surrogate model to determine the viscoelastic parameters of an asphalt mixture in rutting research. Firstly, a wheel tracking test (WTT) for AC-13 was conducted to clarify the flow rutting development mechanism. Secondly, two sets of the AC-13 viscoelastic parameters obtained through the optimization method and the dynamic modulus were used as inputs into the FEM simulation of the WTT to compare the simulation results. Finally, a sensitivity analysis of viscoelastic parameters was performed to improve the efficiency of parameter optimization. The results indicating the viscoelastic parameters obtained by this method could precisely characterize the development law of flow rutting in asphalt mixtures.","PeriodicalId":13601,"journal":{"name":"Infrastructures","volume":"1 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139220160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-27DOI: 10.3390/infrastructures8120168
G. Santarsiero, Antonio D’Angola, Giuseppe Ventura, A. Masi, V. Manfredi, Valentina Picciano, A. Digrisolo
There are many existing buildings for which seismic rehabilitation interventions are required, especially in earthquake-prone areas like Italy. At the same time, the deep energy crisis that Europe is facing highlights the need for sustainable techniques that are able to increase the energy efficiency of buildings. In order to mitigate the social and cultural obstacles for deep renovations of buildings, effective techniques and methods are required to avoid relocating users, which often discourages such interventions. To this purpose and as the main novelty, this research is aimed at presenting a new strengthening technique for reinforced concrete buildings that is able to integrate structural seismic strengthening and energy efficiency improvements. It is made up of new framed structures connected from the outside to the existing building, thus reducing the intrusiveness and relocation needs of users. At the same time, the seismic strengthening technique is conceived for an optimal coupling with energy saving interventions like high-performance external insulation finishing systems. In this study, these techniques are described and applied to a reinforced concrete (RC) school building designed only for gravity loads, according to outdated standards. The results show that the considered strengthening technique increases the seismic performance of the building with respect to both life safety and damage limitation requirements, avoiding any further local interventions to the building’s interior. On the other hand, the energy renovation allows for significant savings, since the resulting reduction in the total non-renewable energy consumption is larger than 80%.
{"title":"Sustainable Renovation of Public Buildings through Seismic–Energy Upgrading: Methodology and Application to an RC School Building","authors":"G. Santarsiero, Antonio D’Angola, Giuseppe Ventura, A. Masi, V. Manfredi, Valentina Picciano, A. Digrisolo","doi":"10.3390/infrastructures8120168","DOIUrl":"https://doi.org/10.3390/infrastructures8120168","url":null,"abstract":"There are many existing buildings for which seismic rehabilitation interventions are required, especially in earthquake-prone areas like Italy. At the same time, the deep energy crisis that Europe is facing highlights the need for sustainable techniques that are able to increase the energy efficiency of buildings. In order to mitigate the social and cultural obstacles for deep renovations of buildings, effective techniques and methods are required to avoid relocating users, which often discourages such interventions. To this purpose and as the main novelty, this research is aimed at presenting a new strengthening technique for reinforced concrete buildings that is able to integrate structural seismic strengthening and energy efficiency improvements. It is made up of new framed structures connected from the outside to the existing building, thus reducing the intrusiveness and relocation needs of users. At the same time, the seismic strengthening technique is conceived for an optimal coupling with energy saving interventions like high-performance external insulation finishing systems. In this study, these techniques are described and applied to a reinforced concrete (RC) school building designed only for gravity loads, according to outdated standards. The results show that the considered strengthening technique increases the seismic performance of the building with respect to both life safety and damage limitation requirements, avoiding any further local interventions to the building’s interior. On the other hand, the energy renovation allows for significant savings, since the resulting reduction in the total non-renewable energy consumption is larger than 80%.","PeriodicalId":13601,"journal":{"name":"Infrastructures","volume":"9 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139228910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-24DOI: 10.3390/infrastructures8120167
J. Oliveira e Sá, Francisco Rebelo, Diogo Silva, Gabriel Teles, Diogo Ramos, José Romeu
Today, everything is connected, including the exchange of data and the generation of new information. As a result, large amounts of data are being collected at an ever-increasing rate and in a variety of forms, a phenomenon now known as Big Data. Recent developments in information and communication technologies are driving the generation of significant amounts of data from multiple sources, namely sensors. In response to these technological advances and data challenges, this paper proposes a Big Data system architecture for paved road monitoring and implements part of this architecture on a section of road in Portugal as a case study. The challenge in the case study architecture is to collect and process sensor data in real time, at a rate of 500 records per second, producing 15 GBytes of data per day, using a real-time data stream for real-time monitoring and a batch data stream for deeper analysis. This allows users to obtain instant updates on road conditions such as the number of vehicles, loads, weather, and pavement temperatures on the road. They can monitor what is happening on the road in real time, receive alerts, and even gain insight into historical data, such as analysing the condition of structures or identifying traffic patterns.
{"title":"A Big Data System Architecture to Support the Monitoring of Paved Roads","authors":"J. Oliveira e Sá, Francisco Rebelo, Diogo Silva, Gabriel Teles, Diogo Ramos, José Romeu","doi":"10.3390/infrastructures8120167","DOIUrl":"https://doi.org/10.3390/infrastructures8120167","url":null,"abstract":"Today, everything is connected, including the exchange of data and the generation of new information. As a result, large amounts of data are being collected at an ever-increasing rate and in a variety of forms, a phenomenon now known as Big Data. Recent developments in information and communication technologies are driving the generation of significant amounts of data from multiple sources, namely sensors. In response to these technological advances and data challenges, this paper proposes a Big Data system architecture for paved road monitoring and implements part of this architecture on a section of road in Portugal as a case study. The challenge in the case study architecture is to collect and process sensor data in real time, at a rate of 500 records per second, producing 15 GBytes of data per day, using a real-time data stream for real-time monitoring and a batch data stream for deeper analysis. This allows users to obtain instant updates on road conditions such as the number of vehicles, loads, weather, and pavement temperatures on the road. They can monitor what is happening on the road in real time, receive alerts, and even gain insight into historical data, such as analysing the condition of structures or identifying traffic patterns.","PeriodicalId":13601,"journal":{"name":"Infrastructures","volume":"126 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139238465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-23DOI: 10.3390/infrastructures8120166
Pedro Limón-Covarrubias, L. Ochoa-Ambriz, David Ávalos-Cueva, José Roberto Galaviz-González, M. Perez-Rea, M. A. Gallardo-Sánchez
The Mexican asphalt paving industry is increasingly interested in using reclaimed asphalt pavement (RAP) to produce hot mix asphalt (HMA) due to its economic and environmental advantages. However, an ill-defined methodology for integrating RAP into the HMA mix design has hindered its use. This paper investigates how compaction energy affects both rejuvenated and non-rejuvenated recycled HMA mixtures. A Superpave gyratory compactor was used to determine the optimal binder content and find a balance between flexibility and stiffness that meets cracking and rutting resistance requirements. Various recycled HMA mixtures were subjected to different compaction energy levels (75, 100, and 125 gyros), different RAP contents (15%, 30%, and 45%), and various dosages (10%, 15%, and 36%) of the rejuvenating additive Maro-1000®, following the blending chart. Performance was evaluated using the Hamburg wheel tracking test (HWTT) and the fracture energy flexibility index test (I-FIT). The results demonstrate that mixtures with RAP, a rejuvenating admixture, and varying compaction energies exhibit favorable mechanical behavior. However, both rejuvenated and non-rejuvenated mixes with 15% RAP showed performance comparable to conventional mixtures. They improved stiffness by up to 46% while reducing the flexibility index to 25%, striking a balanced equilibrium between rutting resistance and cracking susceptibility.
{"title":"Influence of Compaction Energy on the Mechanical Performance of Hot Mix Asphalt with a Reclaimed Asphalt Pavement (RAP) and Rejuvenating Additive","authors":"Pedro Limón-Covarrubias, L. Ochoa-Ambriz, David Ávalos-Cueva, José Roberto Galaviz-González, M. Perez-Rea, M. A. Gallardo-Sánchez","doi":"10.3390/infrastructures8120166","DOIUrl":"https://doi.org/10.3390/infrastructures8120166","url":null,"abstract":"The Mexican asphalt paving industry is increasingly interested in using reclaimed asphalt pavement (RAP) to produce hot mix asphalt (HMA) due to its economic and environmental advantages. However, an ill-defined methodology for integrating RAP into the HMA mix design has hindered its use. This paper investigates how compaction energy affects both rejuvenated and non-rejuvenated recycled HMA mixtures. A Superpave gyratory compactor was used to determine the optimal binder content and find a balance between flexibility and stiffness that meets cracking and rutting resistance requirements. Various recycled HMA mixtures were subjected to different compaction energy levels (75, 100, and 125 gyros), different RAP contents (15%, 30%, and 45%), and various dosages (10%, 15%, and 36%) of the rejuvenating additive Maro-1000®, following the blending chart. Performance was evaluated using the Hamburg wheel tracking test (HWTT) and the fracture energy flexibility index test (I-FIT). The results demonstrate that mixtures with RAP, a rejuvenating admixture, and varying compaction energies exhibit favorable mechanical behavior. However, both rejuvenated and non-rejuvenated mixes with 15% RAP showed performance comparable to conventional mixtures. They improved stiffness by up to 46% while reducing the flexibility index to 25%, striking a balanced equilibrium between rutting resistance and cracking susceptibility.","PeriodicalId":13601,"journal":{"name":"Infrastructures","volume":"167 21 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139242572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-21DOI: 10.3390/infrastructures8120165
Gabriele D’Orso, Leonardo Minaudo, Marco Migliore
Microtransit is a shared mobility service that operates between fixed-route transit and ride-hailing. It operates with a fleet of vans or minibuses within a service zone that is usually located in a rural or suburban car-oriented area with a transport demand that is temporally and spatially dispersed. Microtransit often expects customers to walk a short distance to pick-up/drop-off (PUDO) locations. The PUDO points need to be quickly, easily, and safely reachable by pedestrians. Thus, PUDO locations must be chosen after analyzing the walkability of the suburban area served by microtransit. This paper presents a comparison of macroscale and microscale indicators to assess the walkability of suburban neighborhoods where microtransit has to be introduced. We chose three suburban neighborhoods (Partanna Mondello, Tommaso Natale, and Mondello) in Palermo, Italy, as a study area, aiming to identify the best places to locate PUDO stops for a microtransit service. A GIS database has been built associating each link with a series of qualitative and quantitative attributes. Finally, we developed a walkability index that indicates the attractiveness of specific locations in terms of intermodal walkability. We also identified the critical pedestrian links that need actions to improve their walkability.
{"title":"Comparing Macroscale and Microscale Walkability Indicators to Establish Pick-Up/Drop-Off Locations for a Microtransit Service in a Suburban Area","authors":"Gabriele D’Orso, Leonardo Minaudo, Marco Migliore","doi":"10.3390/infrastructures8120165","DOIUrl":"https://doi.org/10.3390/infrastructures8120165","url":null,"abstract":"Microtransit is a shared mobility service that operates between fixed-route transit and ride-hailing. It operates with a fleet of vans or minibuses within a service zone that is usually located in a rural or suburban car-oriented area with a transport demand that is temporally and spatially dispersed. Microtransit often expects customers to walk a short distance to pick-up/drop-off (PUDO) locations. The PUDO points need to be quickly, easily, and safely reachable by pedestrians. Thus, PUDO locations must be chosen after analyzing the walkability of the suburban area served by microtransit. This paper presents a comparison of macroscale and microscale indicators to assess the walkability of suburban neighborhoods where microtransit has to be introduced. We chose three suburban neighborhoods (Partanna Mondello, Tommaso Natale, and Mondello) in Palermo, Italy, as a study area, aiming to identify the best places to locate PUDO stops for a microtransit service. A GIS database has been built associating each link with a series of qualitative and quantitative attributes. Finally, we developed a walkability index that indicates the attractiveness of specific locations in terms of intermodal walkability. We also identified the critical pedestrian links that need actions to improve their walkability.","PeriodicalId":13601,"journal":{"name":"Infrastructures","volume":"50 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139252527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-20DOI: 10.3390/infrastructures8110164
A. Abdallah, Mehmet E. Ozbek, R. Atadero
Over the last two decades, many researchers have focused on providing new ideas and frameworks to help improve conventional bridge inspection planning approaches, however, little guidance is provided for implementing these new ideas in practice, resulting in limited change. Accordingly, this qualitative study aims to identify the factors that can help improve research products and accelerate research transfer to bridge inspection departments with the goal of enhancing bridge inspection practice. This study used semi-structured interviews, written interviews, and questionnaires for data collection to provide rich results. Responses from twenty-six bridge personnel from state Departments of Transportation (DOTs) across the United States (U.S.) were included in this study. The study found that most participants support a fixed inspection interval over a variable interval since fixed intervals are easier in scheduling and budget planning. Also, participants indicated that the barriers hindering the use of nondestructive techniques are the training required by inspectors, traffic control, and the required access equipment. The study presents the factors change leaders should focus on to facilitate organizational change in DOTs such as enhancing the capacity of DOT staff members and gaining support from the Federal Highway Administration (FHWA)
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Pub Date : 2023-11-17DOI: 10.3390/infrastructures8110163
V. Vijayan, K. Mantalovas, F. Acuto, G. Di Mino
Asphalt binder is a crucial component of asphalt pavements that undergoes ageing over time, which can result in the reduced performance and deterioration of pavements. Consequently, artificial ageing methods play a significant role in providing valuable insights into the ageing behaviour and long-term performance of asphalt binders. However, a consensus on the most effective method for simulating ageing behaviour remains elusive, leading to disparities in the outcomes across different research studies. To address this issue, the study utilises two thermo-oxidative ageing approaches, one focusing on the binder itself and another on the loose asphalt mixture. The study investigates the effect of these ageing methods on the behaviour of asphalt binder using physical, rheological, and chemical characterisation. For the binder ageing method, a rolling thin film oven (RTFO) and a pressure ageing vessel (PAV) were utilised, whereas the loose asphalt mixture ageing was performed in an oven at 95 °C for various durations. The results indicated that the ageing trend differed between the two oxidative ageing approaches as the ageing duration increased. However, by employing an ageing sensitivity index, comparable rheological properties were observed between the binders aged using the PAV for 20 h and the loose asphalt mixture for 5 days. The Fourier Transform Infrared (FTIR) spectroscopy analysis revealed that the ageing methods influenced the functional groups associated with ageing in distinct ways, even though they exhibited similar rheological behaviour. Overall, this study provides a comprehensive understanding of different thermo-oxidative ageing approaches, their correlation, and their relevance to the studied field-aged binders.
沥青胶结料是沥青路面的重要组成部分，随着时间的推移会发生老化，从而导致路面性能下降和老化。因此，人工老化方法在深入了解沥青胶结料的老化行为和长期性能方面发挥着重要作用。然而，对于模拟老化行为的最有效方法仍未达成共识，导致不同研究的结果存在差异。为了解决这个问题，本研究采用了两种热氧化老化方法，一种针对粘结剂本身，另一种针对松散的沥青混合料。研究利用物理、流变学和化学特性分析方法，调查这些老化方法对沥青胶结料行为的影响。在胶结料老化方法中，使用了轧制薄膜烘箱（RTFO）和压力老化容器（PAV），而松散沥青混合料老化则在 95 °C 的烘箱中进行，持续时间长短不一。结果表明，随着老化持续时间的延长，两种氧化老化方法的老化趋势有所不同。不过，通过使用老化敏感性指数，可以观察到使用 PAV 老化 20 小时的粘结剂与使用松散沥青混合料老化 5 天的粘结剂具有相似的流变特性。傅立叶变换红外光谱（FTIR）分析表明，尽管它们表现出相似的流变特性，但老化方法以不同的方式影响了与老化相关的官能团。总之，这项研究让人们全面了解了不同的热氧化老化方法、它们之间的相互关系以及它们与所研究的现场老化粘结剂的相关性。
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