• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.520-525
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• 1996

Recently, the prestressed concrete long-span bridegs are increasingly built at various locations in the world. The mechanical and structural behavior of prestressed concrete bridges is very complex because of nonlinear and time-dependent material behavior and sequential change of structural system due to stepwise construction. These factors may cause construction errors with respect to design value and monitoring system is needed to minimize or to protect construction errors. This study presents the basis development of monitoring system for precise construction of large scale prestressed concrete bridges.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.407-414
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• 2000

Recently the geogrids are being used in some large projects such as Inchon International Airport construction, highway construction, and Korean High-Speed Railway construction with not only the merit of simple construction but also reinforcing efficiency for the soft ground. Main function of roadbed is to provide a stable foundation in terms of bearing capacity and settlement for the subballast and ballsat layers. Differential settlement of the railroad should be avoided. The cyclic laboratory model tests were performed to investigate the settlement behavior of geogrid reinforced railroadbed. The ratio of settlement of roadbed under cyclic loading with three layers of geogrid reinforced is less than 1/2 of the roadbed thickness without reinforcement.

• Journal of Industrial Technology
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• v.31 no.A
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• pp.79-86
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• 2011

This paper is results of centrifuge model experiment of investigating geotechnical engineering behavior of waterproof dike, located in soft grounds, in Saemankem in progress of construction. Centrifuge test with artificially increased gravitational level of 50g were performed to find ground settlements and excess pore-pressures developed during construction of waterproof dike by simulating the construction stages being predicted to occur in field so that the stability of waterproof dike could be assessed.

• Journal of the Korean Society of Safety
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• v.35 no.2
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• pp.76-83
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• 2020

This study examined the effects of perceptual differences of safety leadership between managers and workers on workers' safety attitudes and behavior in two construction sites. In addition, the mediating role of safety attitude between safety leadership and safety behavior across discrepancy level of safety leadership. This study was conducted on two first-tier construction companies within the 100th place in 2019. Two companies were similar in size(100 - 150 billion won) and process from the basement frame finishing stage to start of the ground structure of apartment. In A Site, 40 managers and 73 workers, 42 managers and 77 workers in B site participated the survey on managers' safety leadership, and workers' safety attitude and behavior. The results showed that there was no significant difference between the safety leadership scores assessed by the manager and workers at site B. However, the safety leadership scores assessed by the managers were significantly higher than that by the workers at site A. The workers' safety attitudes and behaviors at site B were higher than those of workers at site A. Moreover, Site B was significantly higher in the effects of safety leadership on safety behavior than Site A. At site B, safety leadership had a significant influence on safety behavior even after controlling the safety attitude of workers. At site A, safety leadership had no significant effect on safety behavior after controlling safety attitude. These findings suggest that there is managers' self-serving bias on safety leadership in site A and that this bias of leadership can negatively affect workers' safety attitude and behaviors. In addition, it can be seen that if the self-serving bias on safety leadership occurs, the manager's safety leadership has less influence on workers' safety behavior.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.417-423
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• 2005

Contractor's opportunistic bidding behavior refers to contractor's deliberate low-bid, which cannot accord with the cost, and expectation for beyond-contractual reward (BCR), the compensation earned through cutting corners or claims after undertaking the construction project. This research applies System Dynamics to develop a model of contractor's pricing with consideration for dimensions of "cost", "market competition", and "BCR". Iterative computer simulations were performed to analyze the effects of contractor's pricing on the market price. The results were then examined by statistical analysis on data collected from 44 highway projects in Taiwan. It is found that the critical force driving the contractors to bid opportunistically is their excessive expectations in BCR under the current environment. Within the price competition mechanism, if the problem of BCR exists, even if the bidding system is further improved, contractors would still prefer opportunistic bidding behavior, and eventually make the whole construction industry operate ineffectively. Therefore, it is crucial to remedy the aforementioned BCR problem by more effective management policy.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.956-962
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• 2009

A high embankment is generally constructed by dividing into several sub-embankments. Unlike any soil embankment, a rock embankment is constructed by means of dynamic compaction. Such a sub-embankment and dynamic compaction may induce an increase of pressure at the lower part of embankment and cause a different behavior of ground from initial status. In this study, settlement of a high rock embankment is estimated using a hyperbolic model taking into construction history. The results from prediction are compared with those obtained from field measurements and large plate loading tests.

• Journal of the Society of Disaster Information
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• v.17 no.1
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• pp.154-164
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• 2021

Purpose: Ten years after basic safety and health education in the construction industry has been implemented, no more maintenance education has been provided, and those who have completed basic safety and health education are exempt from new employee education. As soon as possible, we will seek strategic measures to prevent unstable behavior and prevent safety accidents by legislating conservative education and new recruitment education. Method: In this study, basic safety and health education, which is construction safety education, and human error, which is unstable behavior of new employees, and structural relationship between violation behavior were conducted through survey. Result: The survey analyzed that basic safety and health education in the construction industry and new recruitment education had a significant impact on the human factors of the disaster, Human Error, and the reduction of violations, and confirmed that continuous safety education could increase safety awareness. Conclusion: The insolvency of safety education shall be prevented by the revision of the Act on the remuneration of basic safety and health education and the education of new employees.

• Korean Journal of Construction Engineering and Management
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• v.21 no.3
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• pp.65-75
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• 2020

In this study, the purpose of the study was to verify the relationship between the company's construction safety management system and workers' safety consciousness and safety observance behavior. A survey of 357 workers was conducted and a statistical analysis was performed using the SPSS 25.0 program. As a result, the following main results were obtained: First, it was found that supervisor's capability, inner construction safety management, construction safety education, and construction disaster evaluation have significant effects on the worker's safety consciousness. Second, it was revealed that the worker's safety consciousness had a significant positive effect on the safety observance behavior. Third, it was shown that supervisor's capability, inner construction safety management, construction safety education, and construction disaster evaluation have significant effects on safety observance behavior. In addition, this study confirmed that the management supervisor's ability to handle safety at the work site is the most important factor in safety management in order to enhance the worker's safety consciousness and safety observance behavior.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.04a
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• pp.27-34
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• 2002

In the case of reinforced concrete structures, the knowledge of load transfer in the long-term behavior analysis considering construction sequence is very important. Even though long-term behavior of concrete structures has been widely studied, the studies on the time-dependent axial force variation of shore have been scarce to date. In order to investigate the shore behaviors under actual construction conditions, a three-story test frame was constructed on a construction site. The entire construction schedule for the test frame was made to follow the schedule of an actual three-story frame. To analyze the data collected from the test frame, an analysis method based on the Winkler foundation model was developed. This analysis method accurately Predicts the time-dependent behavior of shore. The analysis results coincide well with those obtained by the Midas GENw program

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.225-228
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• 2006

Fast construction of bridge structures is a new trend of bridge design. Accelerated bridge construction includes the construction of superstructures and substructures. In order to reduce the construction time for substructures, precast prestressed bridge piers are increasingly applied in other countries. One of the main concern in the design of precast piers is the determination of the axial prestress forces. The behavior of the piers should be investigated under service loadings and ultimate conditions. In this paper, the magnitude of prestress is calculated to control the stress at the joint of precast piers. Considering long-term behavior of prestressed piers, P-M diagrams for precast piers are obtained to verify the ultimate behavior of the piers. Based on these studies, precast piers are applied to the light-railway bridge piers.