bridge performance
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2021 ◽  
pp. 1-34
Author(s):  
Eunho Kang ◽  
Hyomun Lee ◽  
Dongsu Kim ◽  
Jongho Yoon

Abstract Useful thermal bridge performance indicators (ITBs) of existing buildings may differ from calculated thermal bridge performance derived theoretically due to actual construction conditions, such as irregular shapes and aging. To fill this gap practically, a more realistic quantitative evaluation of thermal bridge on-site needs to be considered to identify thermal behaviors throughout exterior walls and thus improve the overall insulation performance of buildings. In this study, a case study is conducted using an infrared thermal imaging method to evaluate the thermal bridge of an existing building practically. The study's main purpose is to review the thermal bridge performance indicators measured by the steady-state model under field conditions in terms of convergence and uncertainty. Bayesian MCMC is used to examine the validity of the results by deriving evaluation results in the form of distribution, including uncertainty. After the measurement was completed, an analysis of the results was conducted. As a result of measurement for 3 days, it was found that the thermal bridge part had 1.221 times more heat loss than the non-thermal bridge part, which showed a 6.7% deviation from the numerical method. However, the uncertainty was 0.225 (18.4%, CI 95%), a large figure. This is due to the influence of field conditions and shows the limitations of the steady-state measurement model. Regarding the convergence of the results, the measurement results were found to converge continuously as the measurement time increased. This suggests that valid results can be obtained in the field if the measurement is performed for a sufficient time, even with a thermal bridge measurement method assuming a steady-state.


2021 ◽  
pp. 136943322110480
Author(s):  
Yan Wang ◽  
Dong-Hui Yang ◽  
Yu-Zheng Zhou ◽  
Ting-Hua Yi

The cables of long-span cable-stayed bridges are subjected to substantial tension during long-term service and are more susceptible to corrosion and fatigue failure than concrete structures. Most existing structural health monitoring (SHM) systems do not have monitoring equipment to directly measure cable length, and long-term monitoring of the change in cables is less involved. The displacement response of a bridge is induced by the combination of dynamic effects (wind and highways) and quasi-static effects (temperature). In this paper, the dynamic responses were eliminated by averaging the displacement data for 10 min, and the relationship between temperature and displacement was studied. Based on the monitoring data, the distribution of the thermal field for the bridge was studied and the time variability of the tower displacement was investigated. The correlation was analyzed to study the relationship between the temperature and the tower displacements, the north tower–south tower distance and the tower–girder distances. A strong linear relationship between the temperature and quasi-static responses of the displacements was observed. The thermal expansion coefficient of the effective length of cables was proposed as a quantitative index for long-term cable monitoring. The error in the cable effective length is proposed as the warning index for performance warning research. The results show that the proposed performance warning method can monitor cables and perform warnings when the cable is damaged.


Author(s):  
Fitriati Fitriati ◽  
Satria Prayudi

As information technology rapidly changes workplaces and classrooms, the need for education has shifted from focusing on static skills to the ability to learn in a dynamic environment. Higher education institutions are looking for teaching practices to bridge performance gaps and meet the challenge of ensuring that students are prepared for careers after graduation. During this pandemic, more than 85% of jobs are computer-oriented, but a small percentage of students seek educated qualifications. The skills of the early twentieth century are essential to prepare students for these tasks. The purpose of this research is to determine a consensus on the composition of 21st century skills, measure the views of students and teachers, and determine the challenges students face in the learning process. This was a mix methods study. A perceptual survey accompanied by open-ended questions deepened analysis and understanding. The data was analyzed descriptively and open ended question responses were coded, categorized and analyzed using qualitative data analysis approach. The findings showed student’s the difficulties in developing 21st Century skills. 


CivilEng ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 612-631
Author(s):  
Benjamin Fosu-Saah ◽  
Marwan Hafez ◽  
Khaled Ksaibati

Accelerated pavement testing (APT) facilities has been demonstrated for years as a multi-purpose solution for pavement and non-pavement research. Even though APTs are widely known in the pavement industry, little has been publicized about their successful applications in non-pavement research. This paper provides a survey of APT applications in non-pavement research. The purpose of the survey is to review and encourage APT owners and agencies to explore the opportunities that APT facilities can present to promote non-pavement research initiatives. The survey demonstrates the ability of APTs to conduct research for bridges, transportation technology, drainage, geotechnical engineering, automobiles, environmental engineering, highway safety, among others. Non-pavement research can be incorporated into APT programs to diversify funding sources for research operations and promote cooperation with other agencies. Finally, suggestions for future and current APTs are made in this paper, including evaluating connected vehicles, work zone applications, smart infrastructure, truck platooning effects on bridge performance, sustainable drainage systems, bridges, advancement in geotechnical methods, sustainable fuels, and unmanned aerial systems.


Author(s):  
Eunho Kang ◽  
Hyomoon Lee ◽  
Dongsu Kim ◽  
Jongho Yoon

Abstract Practical thermal bridge performance indicators (ITBs) of existing buildings may differ from calculated thermal bridge performance derived theoretically due to actual construction conditions, such as effect of irregular shapes and aging. To fill this gap in a practical manner, more realistic quantitative evaluation of thermal bridge at on-site needs to be considered to identify thermal behaviors throughout exterior walls and thus improve overall insulation performance of buildings. In this paper, the model of a thermal bridge performance indicator is developed based on an in-situ Infrared thermography method, and a case study is then carried out to evaluate thermal performance of an existing exterior wall using the developed model. For the estimation method in this study, the form of the likelihood function is used with the Bayesian method to constantly reflect the measured data. Subsequently, the coefficient of variation is applied to analyze required times for the assumed convergence. Results from the measurement for three days show that thermal bridge under the measurement has more heat losses, including 1.14 times, when compared to the non-thermal bridge. In addition, the results present that it takes about 40 hours to reach 1% of the variation coefficient. Comparison of the ITB estimated at coefficient of variation 1% (40 hours point) with the ITB estimated at end-of-experiment (72 hours point) results in 0.9% of a relative error.


2021 ◽  
Author(s):  
Ahmed Abdrabbo

Integral abutment bridges have started to become part of the construction industry worldwide. However, they present challenges arising from the monolithic connection between bridge deck and the abutment. Thermal loading induced by daily cycles superimposed on seasonal cycles result in complex soil-structure interaction. Due to uncertainties in integral abutment bridge performance, there is no consensus among different codes on the bridge maximum length limit. A parametric study was carried out, using SAP2000 software, to examine the behavior of horizontal curved concrete slap-on-steel Igirders, under the effect of thermal loading conditions (±65°c). The self-weight of the bridge was considered. Spatial variables, including abutment height, radius of curvature, bridge span length, stiffness of backfill and types of foundation soil, were considered. The numerical analysis results were used to drive equation relating abutment height and bridge span with the maximum bridge length limit, which produces 40 mm horizontal displacement on pile head.


2021 ◽  
Author(s):  
Ahmed Abdrabbo

Integral abutment bridges have started to become part of the construction industry worldwide. However, they present challenges arising from the monolithic connection between bridge deck and the abutment. Thermal loading induced by daily cycles superimposed on seasonal cycles result in complex soil-structure interaction. Due to uncertainties in integral abutment bridge performance, there is no consensus among different codes on the bridge maximum length limit. A parametric study was carried out, using SAP2000 software, to examine the behavior of horizontal curved concrete slap-on-steel Igirders, under the effect of thermal loading conditions (±65°c). The self-weight of the bridge was considered. Spatial variables, including abutment height, radius of curvature, bridge span length, stiffness of backfill and types of foundation soil, were considered. The numerical analysis results were used to drive equation relating abutment height and bridge span with the maximum bridge length limit, which produces 40 mm horizontal displacement on pile head.


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