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Dynamic parameters in reinforced concrete one-way ribbed slabs: Theoretical and numerical

ENGINEERING STRUCTURES 2024年 314卷

作者： Medeiros, Ialysson da S. Lima, Henrique T. de Lima, Douglas M. Alas, Luis E. de M. Lopez-Yanez, Pablo A. Univ Fed Pernambuco Acad Ctr Agreste Grad Program Civil & Environm Engn Marielle Franco Ave BR-55014900 Caruaru PE Brazil Univ Fed Pernambuco Dept Civil & Environm Engn Architecture Ave BR-50740550 Recife PE Brazil

Investigating the dynamic characteristics of slabs is crucial in the construction of modern structures that are lighter and have larger spans, making them susceptible to vibration phenomena;and addressing parameters such as natural frequencies and damping during the design phase can prevent future issues. Traditionally, floor structure design considered strength and control of deflections and cracks. However, concern about the ability to withstand vibrations is crucial. While there are studies on the use of MEMS accelerometers for floor analysis, their integration into continuous monitoring and control methods requires further investigation. In this way, this article explores the increasing sensitivity to vibrations in modern structures, stemming from the pursuit of slimmer and more flexible structural elements due to a reduction in material consumption. The research stands out not only for the effectiveness and reliability of numerical -computational and analytical methods but also emphasizes the validity of the experimental method, which proves to be financially accessible and practical in obtaining dynamic parameters. In this study, the ribbed slabs of reinforced concrete were analyzed for their dynamic characteristics, emphasizing the feasibility of obtaining vibration parameters for these slabs through: analytical analysis based on Mindlin's orthotropic plate theory (with appropriate consideration of the slabs' boundary conditions and the order of the analyzed vibration mode);simplified experimental techniques (heel impact test and the use of micro-electro-mechanical systems - MEMS from smartphones);and numerical analyses with the Finite Element Method using SCIA Engineer v21.1 software (where 150 vibration modes were processed). The comparative analysis revealed good consistency between the assessed natural frequencies, with determination coefficients R 2 of approximately 0.976 between the numerical and experimental methods, and 0.948 between the analytical mo

关键词： Modal analysis Natural frequency Damping ratio Textile industry

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Multidisciplinary reconnaissance investigation covering structural, geotechnical, and architectural based damage to mid-rise residential buildings following the February 6th, 2023 Kahramanmaras,, Türkiye earthquake doublets (Mw 7.8, Mw 7.6)

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SOIL DYNAMICS AND EARTHQUAKE ENGINEERING 2024年 182卷

作者： Celik, Oguz C. Ulker, Mehmet Baris Can Gocer, Caner Guntepe, Sinem Koz, Oguz Eyupgiller, Mustafa Mert Aksu, Mert Yaz, Ali Istanbul Tech Univ ITU Fac Architecture Struct & Earthquake Engn Unit TR-34437 Istanbul Turkiye ITU Disaster Management Inst Earthquake Engn Program Sariyer 34469 Istanbul Turkiye North Carolina State Univ Dept Civil Construct & Environm Engn Raleigh NC 27606 USA ITU Fac Architecture Dept Architecture Taksim Istanbul Turkiye ITU Fac Civil Engn TR-34469 Sariyer Istanbul Turkiye

Kahramanmaras, and its surroundings were devastated with major earthquake doublets of Mw = 7.8 Pazarc & imath;k and Mw = 7.6 Elbistan/Ekinoz & uuml;on February 6th, 2023. While a wide scatter of reinforced concrete (RC) structures experienced damage, mid-rise residential buildings constitute a large bulk with heavy damage or total collapse. Among many reasons, poor concrete strength and brittle fracture of rebars along with liquefaction-caused soil deformations contributed to building damage. This paper investigates structural, geotechnical, and architectural conditions of mid-rise RC residential buildings with heavy damage. The geotechnical component includes the investigation of liquefaction-caused settlement and subsidence of loose foundation soils. Architectural reconnaissance suggests that commonly encountered design mistakes observed in past earthquakes were repeated. Field investigation concludes that loose saturated silty and sandy soils exhibit liquefaction leading to permanent damage on the mid-rise buildings while tunnel-form code-designed RC buildings with seven-to-ten stories performed well.

关键词： Kahramanmaras , earthquakes Geotechnical observations Liquefaction Reconnaissance study Reinforced concrete residential buildings Settlement Structural and architectural damage

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Biostimulation of the In Situ Production of Biosurfactants During the Bioremediation of Diesel Oil in Clayey Soil

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INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH 2021年第6期15卷 947-957页

作者： Decesaro, Andressa Thome, Antonio Colla, Luciane Maria Univ Passo Fundo Fac Engn & Architecture Grad Program Civil & Environm Engn Campus 1BR 285 BR-99052900 Passo Fundo RS Brazil

Despite the continuous advances in the understanding of the mechanisms related to the bioremediation of soils contaminated with hydrocarbons, there are gaps regarding the assessment of the production of biosurfactants in situ. The objective of this work was to verify the effects of biostimulation (ammonium sulfate or whey) and bioaugmentation (B. methylotrophicus) on the in situ production of biosurfactants in soil, evaluated by the determination of surface tension, during the bioremediation of diesel oil. Biostimulation (ammonium sulfate/whey) achieved a total removal of the contaminant of 40%. The application of biostimulation and bioaugmentation together resulted in the removal of 61.64% of the contaminant, 28.04% higher in relation to natural attenuation. For bioaugmentation and biostimulated soils, a decrease in surface tension was observed, indicating the production of biosurfactants in the soil (44.33 mN/m), which was not observed in natural attenuation (61.49 mN/m) or control treatment (64.45 mN/m). In sterile soil, the sorption values were around 20%, showing that there were no different rates of adsorption of the contaminant. Thus, it was found that the joint application of biostimulation and bioaugmentation techniques helped in the production of biosurfactants directly in the soil and increased the biodegradation of diesel oil in the soil. [GRAPHICS] .

关键词： Biosurfactant Hydrocarbons Bioremediation Adsorption

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Improving the Bioremediation and in situ Production of Biocompounds of a Biodiesel-Contaminated Soil

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ENVIRONMENTAL MANAGEMENT 2021年第2期68卷 210-225页

作者： Kreling, Naiara Elisa Simon, Viviane Fagundes, Victoria Dutra Thome, Antonio Colla, Luciane Maria Univ Passo Fundo UPF Fac Engn & Architecture FEAR Postgrad Program Civil & Environm Engn PPGEng Passo Fundo RS Brazil Univ Passo Fundo UPF Fac Engn & Architecture FEAR Grad Environm Engn Passo Fundo RS Brazil

We aimed to produce simultaneously biosurfactants and lipases in solid state fermentation (SSF) using Aspergillus niger, followed by the use of the fermented media on the bioremediation of oily contaminated soil, in order to valuate agro industrial residuals and reduce the contamination. The biocompounds were produced using wheat bran and corncob (80:20), 5% of soybean oil and 0.5% of sugar cane molasses in SSF for 4 d, producing 4.58 +/- 0.69 UE of emulsifying activity and 7.77 +/- 1.52 U of lipolytic activity. This fermented media was used in the bioremediation of a 20% biodiesel contaminated soil, evaluating for 90 d microbial growth, contaminant degradation, and production of lipases and biosurfactants in soils. Six experimental strategies (natural attenuation;biostimulation + bioaugmentation + biocompounds;biostimulation + biosurfactant;biocompounds extract;biostimulation;adsorption of contaminant) were realized. The highest degradation of contaminant was verified in 90 d, of 74.40 +/- 1.76%, and the production of biosurfactants and lipases in situ in the soil was found in 30 d (6.02 +/- 0.24% of reduction in surface tension and 6.62 +/- 0.17 UL of lipid activity in soil) for the same experiment (biostimulation + bioaugmentation + biocompounds). The addition of biostimulation + biosurfactant promotes higher biodegradation (66.00 +/- 0.92%) of the contaminant than the biocompounds extract (59.58 +/- 0.34%). The use of a solid fermented culture medium containing both biocompounds was feasible for the treatment of contaminants, demonstrating the potential for environmental application without the need for purification processes.

关键词： Biosurfactant Surface tension Lipase Aspergillus niger Soil adsorption Natural attenuation

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Echoes of Tradition: Virtual-Reality Media in Improving Spatial Space Experience 3D Virtual Tour of Kampung Adat Pulo Garut, West Java, Indonesia

Echoes of Tradition: Virtual-Reality Media in Improving Spat...

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STEM Education Conference (iSTEM-Ed), International

作者： M.F. Rahman A.Y. Permana I Susanti J. Akbardin K. Wijaya S. Handayani Architecture Study Program Faculty of Technology and Vocational Education Universitas Pendidikan Indonesia Bandung Indonesia Civil Engineering Study Program Faculty of Technology and Vocational Education Universitas Pendidikan Indonesia Bandung Indonesia Architecture Study Program Faculty of Civil Engineering and Planning Universitas Kebangsaan Republik Indonesia Indonesia Bandung Indonesia Agro-industrial Education Study Program Faculty of Technology and Vocational Education Universitas Pendidikan Indonesia Bandung Indonesia

ISBN: (数字)9798350365979

ISBN: (纸本)9798350365986

In the current digital era, virtual reality (VR) technology is rapidly expanding across various fields, including education and cultural preservation. This technology offers immersive opportunities to explore and experience architectural spaces, promising increased understanding and learning motivation. Despite being relatively new in Indonesia, the application of VR has shown significant potential for education and cultural preservation through the implementation of a 3D virtual tour in Kampung Adat Pulo Garut. Therefore, this research aimed to develop VR media to enhance users' spatial experience and preserve the cultural values of Kampung Adat Pulo Garut through interactive learning. The method used was Research and Development (R&D) through the Multimedia Development Life Cycle (MDLC) model. The equipment used was LiDAR Scanner FJD Trion P1 Series, DJI Mavic Air 2S Drone, and Sony A6000 Camera. The method used included aerial and terrestrial mapping, 3D modeling, and the development of virtual environments through Unreal Engine. The developmental process included various stages, namely concept, design, material collection, compilation, testing, and distribution. The result showed an interactive 3D virtual tour of Kampung Adat Pulo Garut, called “Echoes of Tradition.” Unreal Engine was found to enable detailed visualization of traditional architecture and village environments with high accuracy and interactivity. The final product offered an immersive learning experience, enriching users' experience, and enabling digital preservation of cultural heritage. The next step, to get an overview of the research results, used a questionnaire as an instrument which was distributed to a total of 250 respondents. Furthermore, the potential implication of VR in education and cultural preservation was identified, guiding similar applications in the future. By improving accessibility and engagement in spatial and cultural learning, VR offered new avenues in education and cultu

关键词： Visualization Three-dimensional displays Education Virtual environments Media User experience Cultural differences

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Building Information Modeling Applied to Daylight Dynamic Simulation Considering Local and Global Climate Change

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SSRN 2024年

作者： Michelon, Michelli Gongalves Miri, Majid da Rocha Menezes, Leonardo Junior Ramos, Greici Barata, Marcio Santos Zemero, Bruno Ramos Postgraduate Program in Architecture and Urbanism Federal University of Para Brazil Sweco AB Sweden Postgraduate Program in Mechanical Engineering Federal University of Para Brazil Postgraduate Program in Civil Engineering Federal University of Santa Catarina Brazil

The EN 17037:2018 standard, titled "Daylight in Buildings", is recognized as a step in the right direction concerning daylighting and has been used as the basis for the recently revised Brazilian standard. In this context, this study aims to delve into the understanding of the daylight performance in buildings in Brazil by analyzing the advancements and challenges in NBR 15215/15575:2022. Two methods will be employed: the computational daylight performance simulation method and the abacus method, following the revision of NBR 15575:2022, in a Housing of Social Interest (HIS) located in the city of Belem, Brazil. Since it is a digital prototype and not a physical one, the reliability of the simulations was verified by comparing the results obtained with the abacus method, which also allowed for an analysis of the case study using this alternative approach from the standard. The study aims to identify the best workflow for applying the standard, based on an investigation of dynamic simulation software and the impact of future-urban weather files, seeking to propose improvements to the standard. The results demonstrate the efficiency and accuracy of building information modeling, specifically the AftabRad plugin, for dynamic simulations in accordance with normative criteria, as well as the need to include urban weather files in the standard. © 2024, The Authors. All rights reserved.

关键词： Climate change

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Influences of COVID-19 pandemic on travel patterns across past, present, and future

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INTERNATIONAL JOURNAL OF URBAN SCIENCES 2025年第2期29卷 405-429页

作者： Gim, Tae-Hyoung Tommy Park, Yunmi Seoul Natl Univ Grad Sch Environm Studies Interdisciplinary Program Landscape Architecture I Seoul South Korea Seoul Natl Univ Environm Planning Inst Seoul South Korea Seoul Natl Univ Dept Civil & Environm Engn Seoul South Korea Seoul Natl Univ Inst Construct & Environm Engn Seoul South Korea

As societies strive to return to pre-COVID-19 norms, there's growing recognition of the profound changes people have experienced over the past two and a half years. This has prompted discussions on how to shape future transportation strategies to align with evolving lifestyles. Understanding people's travel patterns before, during, and after the pandemic is crucial for shaping post-pandemic actions. This study investigates the relationship between travel patterns across these phases, with a focus on the pandemic's mediating effects. Using structural equation modelling and data from 7,613 U.S. survey responses, we uncover noteworthy shifts in travel behaviour dynamics. During the pandemic, policy measures and sociodemographic factors significantly influenced travel. However, these effects may diminish as measures are lifted and vulnerabilities no longer correlate with sociodemographics. In contrast, past travel behaviour and attitudes, especially favouring alternative modes of transportation, are expected to have a more enduring impact in the post-pandemic era. This shift is likely to emerge 'strengthened new normal,' especially among those who reduced travel and embraced alternative modes. Future travel policies should anticipate and accommodate these evolving dynamics. Promoting diverse transportation modes beyond private vehicles will be crucial as travel behaviour undergoes transformation. Thus, policy formulation should consider a range of scenarios to address these changing preferences and behaviours.

关键词： Travel behaviour COVID-19 new normal lifestyle mediation effect partial least squares structural equation modelling

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Analysis of Different Parameters in the Electrical Resistivity Test of Concrete

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INTERNATIONAL JOURNAL OF civil ENGINEERING 2021年第1期19卷 27-38页

作者： Lencioni, Julia W. Medeiros-Junior, Ronaldo A. Vale Paraiba Univ FEAU Architecture & Urbanism Coll Dept Civil EngnEngnUNIVAP Sao Jose Dos Campos SP Brazil Fed Univ Parana UFPR Ctr Politecn Civil Engn Studies Ctr CESEC Postgrad Program Civil Construct Engn PPGECC Curitiba Parana Brazil

Electrical resistivity is widely used to monitor the durability of concrete structures. However, the results obtained can be misinterpreted due to the effect of several parameters on the test. Therefore, the effect of six parameters on the electrical resistivity was investigated in this article. The studied parameters were (1) the thickness of the concrete cover;(2) the contact with the concrete mold;(3) the concrete aging;(4) the chloride presence;(5) the type of cure and exposure;and (6) the position of the equipment regarding the reinforcement direction. Tests were performed on aged non-reinforced concrete specimens (5 years old) and freshly casted specimens. The results showed that variation in the thickness of the reinforcement covers from 1.5 to 3.0 cm affects the electrical resistivity measurements, independently of the w/c ratio. The contact of the concreting mold with the specimen did not influence the values of electrical resistivity, independently of the w/c ratio. The effect of the chlorides incorporated into the mass of the concrete during casting is not significant on the electrical resistivity at 28 days. The electrical resistivity was 13.2% higher in specimens cured in a moist chamber, compared to curing in an uncontrolled external environment. The electrical resistivity was no longer influenced by the steel at a minimum parallel distance of 8.0 cm. Measurements performed perpendicular to the bar were not affected. These results are very important for a better interpretation of the results of this technique.

关键词： Electrical resistivity Werner method Reinforcement Curing Concrete age

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Enhancing routes selection with real-time weather data integration in spatial decision support systems

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SPATIAL INFORMATION RESEARCH 2024年第4期32卷 373-381页

作者： Ye, Xinyue Li, Shoujia Das, Subasish Du, Jiaxin Texas A&M Univ Dept Landscape Architecture & Urban Planning College Stn TX 77840 USA Texas A&M Univ Ctr Geospatial Sci Applicat & Technol College Stn TX 77840 USA Texas A&M Univ Dept Comp Sci & Engn College Stn TX 77840 USA Texas State Univ Civil Engn Program San Marcos TX 78666 USA

A notable shortcoming in contemporary digital navigation systems is their failure to incorporate live weather data. This study investigates the possibility of improving urban navigation experiences by integrating real-time weather data. We developed a navigation tool that utilizes weather data from the OpenWeather API, providing users with real-time insights into weather conditions such as temperature, wind speed and direction, precipitation, and atmospheric pressure. This tool enables users to make informed decisions about their routes and travel plans by providing updated temperature information for selected routes and assessing the risk of road sections based on weather conditions. Incorporating weather data into navigation systems has the potential to enhance driving safety, minimize travel durations, and alleviate weather-related disturbances in urban settings.

关键词： Weather integration Real-time weather data Navigation tool Decision support systems

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Who remained happy despite the pandemic?: the impact of changed life situations and mobility and perceptions and attitudes toward the altered lifestyle during COVID-19

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JOURNAL OF ASIAN architecture AND BUILDING ENGINEERING 2025年第2期24卷 985-999页

作者： Park, Yunmi Gim, Tae-Hyoung Tommy Seoul Natl Univ Inst Construct & Environm Engieering Dept Civil & Environm Engn Seoul South Korea Seoul Natl Univ Interdisciplinary Program Landscape Architecture Grad Sch Environm Studies Integrated Major Reg Studies & Spatial Analyt Seoul South Korea Seoul Natl Univ Environm Planning Inst Seoul South Korea Seoul Natl Univ Grad Sch Environm Studies 222 Bldg 82Gwanak Ro 1 Seoul 08826 South Korea

This study explored the determinants of happiness during the COVID-19 pandemic by emphasizing a broad range of factors, including individual (i.e. socio-demographic status, life situations, attitudinal and perceptual characteristics) and policy restrictions. In particular, the study delved into the impact of changes in life situations and mobility, as well as perceptions and attitudes toward the altered lifestyle during COVID-19, on happiness. By analyzing data with 75 items from a U.S. nationwide survey in 2020, this study found that socio-demographic factors played a significant role in increasing happiness specifically when income increased and individuals transitioned from unemployment to employment or sustained employment during the pandemic. Happiness was also significantly reduced by COVID-19 altered attitudinal and perceptual changes such as restricted social interactions and activities, perception of infection risk, avoidance of online alternatives, perceived infection risk from close relationships, and a preference for compactness. Individuals who were users of public transportation before COVID-19 reported lower levels of happiness during the pandemic. This comprehensive exploration underscores the multifaceted nature of happiness during the COVID-19 pandemic, highlighting the intertwined roles of socio-demographic factors, changes in life circumstances, and attitudes and perceptions to new life style.

关键词： COVID-19 happiness attitudes perception life changes PLS-SEM

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