Frontiers in Built Environment最新文献

{"title":"Assessing the impact of sample size and geology on earthen embankment design and construction","authors":"H. O. Ulloa, Alex Ramirez, Navid H. Jafari, I. Harrouch, Bradley Barth","doi":"10.3389/fbuil.2024.1279383","DOIUrl":"https://doi.org/10.3389/fbuil.2024.1279383","url":null,"abstract":"This technical paper investigates the influence of sample size and geologic characteristics on the geotechnical design of levee embankments. Sample quality plays a vital role in quantifying engineering properties for levee embankment projects, and numerous studies have highlighted the impact of sample disturbance on such engineering properties. Despite this evidence, conventional tube and piston samplers of different diameters continue to be widely used, potentially leading to underestimation of shear strength. The paper focuses on comparing 7.6 cm and 12.7 cm diameter undisturbed Shelby tube samples and CPT data collected from three levee sites in the Greater New Orleans Area, Louisiana, USA, which encompass diverse geologic histories. The study aims to assess the effect of industry used samples size and geology on levee construction costs. The findings provide valuable insights into optimizing sample collection methods and improving geotechnical design for earthen embankments.","PeriodicalId":505606,"journal":{"name":"Frontiers in Built Environment","volume":"97 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140984167","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}

{"title":"Effects and optimization of airflow on the thermal environment in a data center","authors":"Di Jiang","doi":"10.3389/fbuil.2024.1362861","DOIUrl":"https://doi.org/10.3389/fbuil.2024.1362861","url":null,"abstract":"In this research, the escalating energy consumption challenges in data centers are addressed by optimizing airflow organization designs. Through the use of computational fluid dynamics (CFD) simulations, three different airflow strategies were evaluated and improved: underfloor precision air conditioning, inter-column air conditioning, and backplane air conditioning. These cooling systems, which are usually considered in isolation, were compared in a comprehensive manner to get a full picture of their efficiency and effectiveness. The findings reveal that the implementation of cold aisle containment (CAC) or hot aisle containment (HAC) significantly improves air supply efficiency (ASE) and reduces the supply heat index (SHI), leading to a more uniform temperature distribution and enhanced cooling performance. Specifically, the ASE increased from 65.69% to 85.57% and 90.25% for underfloor precision air conditioning and from 71.29% to 92.16% and 92.17% for inter-column air conditioning, with corresponding reductions in SHI. The backplane cooling system offered consistent ambient temperatures throughout the room, eliminating thermal hotspots without the need for aisle containment. This study offers a comparative analysis of different airflow organization schemes, highlighting the benefits of aisle containment in precision and inter-column air conditioning and the suitability of backplane air conditioning for high-density cooling without the need for traditional aisle separation. The results are crucial for informing energy-efficient cooling strategies in data center design and operation.","PeriodicalId":505606,"journal":{"name":"Frontiers in Built Environment","volume":" 47","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140991772","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}

{"title":"Seismic evaluation of Site-City interaction effects between city blocks","authors":"F. Vicencio, Nicholas A. Alexander","doi":"10.3389/fbuil.2024.1403642","DOIUrl":"https://doi.org/10.3389/fbuil.2024.1403642","url":null,"abstract":"In urban environments, buildings are often seismically designed with their standalone response, such as isolated structures devoid of surrounding structures. Nonetheless, there is always a chance that a significant seismic interaction between nearby buildings through the underlying soil will occur in big urban areas with high building densities. This paper evaluates the Site-City interaction (SCI) between different city block arrangements under seismic excitation given different parameters of the buildings and centre-to-centre interbuilding distances. A database of strong ground motion records with Far-Field, Near-Field Without Pulse and Near-Field Pulse-Like characteristics are employed. The results suggest that the SCI effects were strongly influenced by the building properties and resonance effects of the soil stratum. Furthermore, as a mean for all the earthquakes considered here, the SCI can amplify or reduce the seismic response of the buildings, depending on the relative position between the city blocks.","PeriodicalId":505606,"journal":{"name":"Frontiers in Built Environment","volume":" 107","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140992986","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}

{"title":"Predicting the fire-induced structural performance of steel tube columns filled with SFRC-enhanced concrete: using artificial neural networks approach","authors":"Christo George, Edwin Zumba, Maria Alexandra Procel Silva, S. S. Selvan, Mary Subaja Christo, Rakesh Kumar, Atul Kumar Singh, Sathvik S., Kennedy Onyelowe","doi":"10.3389/fbuil.2024.1403460","DOIUrl":"https://doi.org/10.3389/fbuil.2024.1403460","url":null,"abstract":"Predicting the axial Shortening strength of concrete-filled steel tubular (CFST) columns is an important problem that this study attempts to solve for civil engineering projects. We suggest using a deep learning-based artificial neural network (ANN) model to address this issue, taking into account the intricate relationship between steel tube and core concrete. The model, called ANN-SFRC (Steel Fibre Reinforced Concrete), surpasses an R2 threshold of 0.90 and achieves impressive R2 values across different types of CFST columns. Compared to traditional linear regression methods, the ANN-SFRC model significantly improves accuracy, with an observed inaccuracy of less than 3% compared to actual values. With its reliable approach to forecasting the behavior of CFST columns under axial compression, this high-performance instrument enhances safety and accuracy during the design and planning stages of civil engineering.","PeriodicalId":505606,"journal":{"name":"Frontiers in Built Environment","volume":" 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140996602","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}

{"title":"Bond-slip behavior of steel reinforcing bars in ultra-high performance concrete for field-cast connection of precast bridge decks","authors":"Ali Shokrgozar, Bipin Aryal, A. Ebrahimpour, M. Mashal","doi":"10.3389/fbuil.2024.1354657","DOIUrl":"https://doi.org/10.3389/fbuil.2024.1354657","url":null,"abstract":"In Accelerated Bridge Construction (ABC), Ultra-High Performance Concrete (UHPC) is often used for connecting precast concrete bridge components, including deck portions of the Deck Bulb-T girders. An alternative low-cost non-proprietary UHPC has been proposed for use in place of the proprietary UHPC for connecting the precast components. The pullout behavior of steel reinforcing bars in closure pour with typical range for embedment lengths is studied for both proprietary and non-proprietary UHPC materials.","PeriodicalId":505606,"journal":{"name":"Frontiers in Built Environment","volume":" 34","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140997180","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}

{"title":"Identification of optimal accelerometer placement on trains for railway switch wear monitoring via multibody simulation","authors":"Zhicheng Hu, Albert Lau, Jian Dai, Gunnstein T. Frøseth","doi":"10.3389/fbuil.2024.1396578","DOIUrl":"https://doi.org/10.3389/fbuil.2024.1396578","url":null,"abstract":"Accelerometers play a crucial role in the railway industry, especially in track monitoring. Traditionally, they are placed on the railway tracks or often on bridges to monitor the health and condition of the infrastructure. Recently, there has been an increased focus on using regular trains to monitor the condition of railway infrastructure. Often, the sensors are placed based on certain assumptions without much scientific evidence or support. This paper utilizes the multibody simulation software GENSYS to identify the optimal placement of accelerometers on a passenger train for monitoring railway switch wear. Switch wear profiles were generated systematically and used as input for the simulations, studying acceleration at a total of 93 locations distributed among the wheelsets, bogies, and carbody. Based on both time and frequency domain analyses, optimal sensor locations were identified, generally close to the first bogie or wheelset at the leading carbody. Accelerations generated by the wheelset passing the switch can also be captured in the carbody, but it is important to note that these are several orders lower in magnitude compared to the acceleration on the wheelset. If accelerometers are to be placed in the carbody, correct sensitivity must be chosen, and a high-pass filter should be applied to capture the acceleration signals associated with switch wear. The study confirms that there is a direct correlation between the depth of switch wear and the magnitude of the acceleration. It remains effective even under various curve radii and train speeds.","PeriodicalId":505606,"journal":{"name":"Frontiers in Built Environment","volume":" 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140995367","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}

{"title":"Influential factors for risk assessment and allocation on complex design-build infrastructure projects; the Texas experience","authors":"Vassiliki Demetracopoulou, William J. O’Brien, N. Khwaja","doi":"10.3389/fbuil.2024.1330506","DOIUrl":"https://doi.org/10.3389/fbuil.2024.1330506","url":null,"abstract":"Introduction: The design-build (DB) delivery method is used to deliver increasingly complex transportation infrastructure projects associated with higher uncertainty. As such, allocating risks in the contract between the owner and design-builder becomes challenging and often leads to higher initial bids, increased contingency, or claims. Learnings from implementation worldwide have underlined the need for improving risk allocation in DB contracts. Most existing studies address risk allocation mechanisms to manage contingency at the contract level. Other studies have recognized the need for owners to adapt their processes to better allocate risks in DB contracts. This study explored the influential factors for risk assessment and allocation for complex DB infrastructure projects, addressing the opportunity to improve transportation owners’ risk allocation processes before the design-builder is selected and the DB contract is awarded.Method: The objectives of this work were achieved by utilizing empirical data collected through 20 interviews with Texas Department of Transportation and private sector experts. The interview data were analyzed using inductive and axial coding. Inductive coding allowed themes to emerge without a pre-existing framework, identifying six influential factors and six pertinent risks on complex DB projects.Results: These factors include the (i) Quality of DB teams, (ii) Level of up-front investigation, (iii) Limitations on the timing of letting, (iv) Design optimization opportunities, (v) Project-specific requirements, and (vi) Relationships with third parties. Through axial coding, the interaction and frequency between the factors and risks were also examined. The coded interactions demonstrated how the identified factors influence allocation for six pertinent risks including right-of-way acquisition, stakeholder approval, site conditions, permits and third-party agreements, railroad interaction, and utility adjustments and coordination. Findings indicate that the evaluation of these interactions can shift the risk allocation from baseline norms established by an agency to correspond to project-specific needs.Contribution: In contributing to the infrastructure project management, this is the first study to examine the factors that influence risk allocation in complex DB projects and examine interactions with pertinent risks, setting the foundation for optimizing allocation based on project-specific needs. In practice, the findings presented in this study can guide owners in adapting their allocation practices, managing, and developing their strategic plan for delivering complex DB projects. The findings can also assist contractors in pricing risks more efficiently and increase competitive bidding.","PeriodicalId":505606,"journal":{"name":"Frontiers in Built Environment","volume":" 34","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140996012","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}

{"title":"Evaluating the impact of indoor aerosols on the performance of real-time radon sensors","authors":"Joan F. Rey, Nicolas Meisser, Dusan Licina, J. Goyette Pernot","doi":"10.3389/fbuil.2024.1407499","DOIUrl":"https://doi.org/10.3389/fbuil.2024.1407499","url":null,"abstract":"Radon, a naturally occurring radioactive gas, poses a significant health risk by accumulating in buildings and potentially leading to lung cancer. Depending on building construction and geographical location, radon levels can vary substantially both within individual buildings and between different buildings. While previous studies have primarily focused on the impact of temperature and relative humidity on radon devices, the influence of aerosols remains largely unexplored. This paper presents a comprehensive evaluation of the influence of indoor aerosol sources on the performance of real-time radon sensors, encompassing consumer, medium, and research-grade devices. Measurements were performed at relatively low (300 Bq/m3) and high (2′000–3′000 Bq/m3) radon levels in a controlled environment—a stable atomic shelter with constant temperature and humidity conditions. Six different aerosols sources were introduced to produce aerosols of different sizes and concentrations. The results suggest that the tested indoor aerosols did not significantly influence the performance of radon devices, irrespective of their grade or detection method. Consequently, sensor performance and the radon levels being investigated may exert a more significant influence on the obtained results than aerosol levels alone. This paper provides valuable insights into the influence of indoor environment on the performance of radon measuring devices, underscoring the importance of understanding their utility and application scope for researchers, professionals, and the general public alike.","PeriodicalId":505606,"journal":{"name":"Frontiers in Built Environment","volume":" 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140999191","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}

{"title":"Navigating occupational safety and health challenges in sustainable infrastructure projects: a comprehensive review","authors":"Ahmad Baghdadi","doi":"10.3389/fbuil.2024.1414366","DOIUrl":"https://doi.org/10.3389/fbuil.2024.1414366","url":null,"abstract":"Ensuring occupational safety and health (OSH) is paramount in infrastructure projects due to their inherently high-risk nature and the increased likelihood of accidents. Despite its importance, numerous obstacles impede the successful adoption of OSH measures in these settings. Addressing these challenges is key to not only implementing OSH protocols effectively but also to improving working conditions and managing other operational facets like quality and environmental concerns, ultimately resulting in better infrastructure developments. Adopting proactive OSH strategies is crucial for preventing significant accidents and fostering a safety culture within infrastructure projects. This review focuses on identifying the primary obstacles and barriers to effective OSH in infrastructure projects, laying the groundwork for improving safety performance in the sector. It highlights organizational and legislative issues as the foremost challenges due to their direct impact on safety culture, resource distribution, compliance, and accountability. Although factors related to environmental and safety practices are deemed less critical, they are nonetheless vital for comprehensive risk management and the promotion of a safe working environment. Tackling these issues is imperative for cultivating a strong safety culture and safeguarding the health of workers on infrastructure projects. It is also essential to acknowledge the distinct OSH challenges presented by different construction scenarios to devise customized safety measures and effectively reduce risks. This review emphasizes the necessity of recognizing the unique aspects of each construction project, addressing specific dangers, and meeting regulatory demands to achieve thorough safety management.","PeriodicalId":505606,"journal":{"name":"Frontiers in Built Environment","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141016801","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}

{"title":"Feasibility and greenhouse gas emissions of timber structures in solar photovoltaic carport construction","authors":"S. Ranta, Elena Akulenko, Hugo Huerta, Shuo Wang, S. Jouttijärvi, Kati Miettunen","doi":"10.3389/fbuil.2024.1379956","DOIUrl":"https://doi.org/10.3389/fbuil.2024.1379956","url":null,"abstract":"This contribution focuses on reducing the greenhouse gas (GHG) emissions of solar photovoltaic (PV) carport structures by replacing carbon-intensive steel with a wood-based material. There is a growing need for PV systems that are suitable for urban environments where the lack of roof spaces and open land limits the use of traditional PV installations. To date, PV carports have been mainly constructed with steel, which has a high carbon footprint and can be considered aesthetically unattractive. Wood structures, on the other hand, could act as carbon storage and thus reduce the GHG emissions of the whole system. Emissions and costs of supporting structures for PV systems have received very little attention, and there is virtually no literature specific to them. This study compares wood-based glued laminated timber (GLT) structures with conventional steel structures by investigating the GHG emissions and economic feasibility. The simulated 485 kWp system with wooden structures yielded base-case lifetime GHG emissions of 11.3 g CO2 eq/kWh in Turku Finland (60°N), and 8.2 g CO2 eq/kWh in Dijon France (47° N), representing a 48% lower value compared to systems with steel structures. Furthermore, wooden structures were competitive in terms of costs, being approximately 25% cheaper. Thus, wooden structures provide a very attractive way to make infrastructure integrated PV more sustainable.","PeriodicalId":505606,"journal":{"name":"Frontiers in Built Environment","volume":"7 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141019361","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}