• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6A
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• pp.1023-1032
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• 2006

In this paper, a new method for the bridge maintenance is proposed to overcome the limit of the existing methods and to implement the preventive bridge maintenance system. The proposed method can establish the lifetime optimum maintenance strategy of the deteriorating bridges considering the life-cycle performance as well as the life-cycle cost. The lifetime performance of the deteriorating bridges is evaluated by the safety index based on the structural reliability and the condition index detailing the condition state. The life-cycle cost is estimated by considering not only the direct maintenance cost but also the user and failure cost. The genetic algorithm is applied to generate a set of maintenance scenarios which is the multi-objective combinatorial optimization problem related to the life-cycle cost and performance. The study examined the proposed method by establishing a maintenance strategy for the existing bridge and its advantages. The result shows that the proposed method can be effectively applied to deciding the bridge maintenance strategy.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.5
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• pp.57-66
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• 2023

Asset valuation of social infrastructure is essential for rational decision-making for efficient management of assets. In addition, it can be an indicator for correctly recognizing assets. In general, Korea applies depreciated replacement cost based on the straight-line method to evaluate asset value, yet this is unsuitable for evaluating actual value because it is depreciated at a constant rate over the useful life period. In order to evaluate the asset value considering the performance of the bridge, the performance index of the bridge is estimated using the Weibull distribution. Using the estimated performance indicators and defect index, a new asset value evaluation method is proposed and compared and analyzed with the existing method. The proposed valuation method can take into account the performance of the bridge, so it is judged to be more objective and reasonable than existing method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.324-327
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• 2011

The design requirement for ground mounted sign structures are fairly well defined in the AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaries, and Traffic Signals and consists of applying an equivalent pseudo-dynamic loading to account for the dynamic effects of wind loads and ignores the dynamic effect due to moving vehicle loads. This design approach, however, should not be applied to the design of bridge mounted sign structures because ignoring the dynamic effects of the moving vehicle loads may produce non-conservative results, since the stiffness of the bridge structure can greatly influence the behavior. Not enough information is available in the literatures which provide guide lines to include the influence of moving vehicles in the design of the bridge mounted sign structures. This paper describes a theoretical methodology, Bridge-Vehicle Interaction Element, which can be utilized to account for the dynamic effect of moving vehicles. A case study is also included where this methodology was successfully applied. It was concluded that the bridge-vehicle interaction finite element developed can provide a more accurate representation of the behavior of bridge mounted sign structures. The result of these analysis enabled development of simple and effective retrofitting scheme for the existing support system of bridge-mounted-structure.

• Steel and Composite Structures
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• v.12 no.3
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• pp.261-273
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• 2012

This study proposes and examines a circular composite bridge pier for seismic resistance. The axial and flexural strengths of the proposed bridge pier are provided by the longitudinal reinforcing bars and the concrete, while the transverse reinforcements used in the conventional reinforced concrete pier are replaced by the steel tube. The shear strength of this composite pier relies on the steel tube and the concrete. This system is similar to the steel jacketing method which strengthens the existing reinforced concrete bridge piers. However, no transverse shear reinforcing bar is used in the proposed composite bridge pier. A series of experimental studies is conducted to investigate the seismic resistant characteristics of the proposed circular composite pier. The effects of the longitudinal reinforcing bars, the shear span-to-diameter ratio, and the thickness of the steel tube on the performance of strength, ductility, and energy dissipation of the proposed pier are discussed. The experimental results show that the strength of the proposed circular composite bridge pier can be predicted accurately by the similar method used in the reinforced concrete piers with minor modification. From these experimental studies, it is found that the proposed circular composite bridge pier not only simplifies the construction work greatly but also provides excellent ductility and energy dissipation capacity under seismic lateral force.

• Interaction and multiscale mechanics
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• v.5 no.3
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• pp.187-210
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• 2012

Cable-stayed bridges are commonly used in modern bridge engineering for covering long spans. In some special cases, the designer is obliged to build such a bridge over an existing fault. Activation of this fault is possible to bring about a relative displacement or separation movement between two neighboring pylons of the bridge built on opposite sides of the fault. In this work, the effect of such a fault-induced pylon displacement on bridge's deformations and on cables' strength is thoroughly studied for several types of cable-stayed bridges and useful conclusions are drawn aiming the design. The influence of a possible earthquake and traffic loads crossing the bridge when the pylons are moving away from each other is not examined.

• Journal of Navigation and Port Research
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• v.35 no.9
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• pp.707-715
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• 2011

To propose an ergonomic layout on the bridge, this study conducted a usability evaluation on the on-bridge navigational equipment of a college training ship that is in use at present. Through the usability evaluation on the training ship navigators, the possibility of operational errors with navigational equipment, the possibility of readout errors with display devices and even the effect of navigational equipment on navigation were evaluated beyond the scope of existing layouts, which adopt only the importance and usage frequency of navigational equipment. By taking ergonomic variables into consideration, this study suggested an optimized layout for on-bridge navigational equipment using a mathematical programming model.

• Journal of the Earthquake Engineering Society of Korea
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• v.18 no.1
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• pp.1-8
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• 2014

The purpose of this study was to investigate the performance of hollow reinforced concrete bridge column systems with reinforcement details for material quantity reduction. The proposed reinforcement details have economic feasibility and rationality and make construction periods shorter. A model of hollow reinforced concrete bridge columns was tested under a constant axial load and a quasi-static cyclically reversed horizontal load. As a result, proposed reinforcement details for material quantity reduction were equal to existing reinforcement details in terms of required performance. The companion paper presents the experimental and analytical study for the performance assessment of hollow reinforced concrete bridge column systems with reinforcement details for material quantity reduction.

• Structural Engineering and Mechanics
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• v.49 no.4
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• pp.463-477
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• 2014

In this paper, seismic performance of Kozyatagi Bridge is evaluated by employing nonlinear elasto-plastic dynamic analysis and the deformation-based performance. The time-history records of the 1999 Izmit, 1971 San Fernando and 1989 Loma Prieta earthquakes are modified by adopting a probability of exceedance of 2% in 50 years corresponding to the return period of 2475 years. The analysis is carried out for three different bearing cases which are movable bearings, restrained bearings, and movable bearings with viscous fluid dampers in the radial direction. The analysis results show that the bridge can be retrofitted with viscous fluid dampers. In this case the reinforced concrete piers need not be strengthened by any jacketing techniques in order to preserve the original architectural appearance of the bridge. The retrofitting design of the bridge with viscous fluid dampers is also presented in detail.

• Smart Structures and Systems
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• v.17 no.4
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• pp.559-576
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• 2016

This study is intended to propose a precast bridge deck system, which has ribbed loop joints between the decks and lacks internal tendons to improve the workability of existing precast deck system. A composite bridge deck specimen was fabricated using the proposed precast deck system, and static and fatigue load tests were conducted to evaluate the structural behavior and the crack pattern of the deck. Leakage test of the deck joints was also conducted and finite element analysis was carried out to compare with the test results.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.916-921
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• 2004

At present, the highest operation speed of general domestic train is in the level of 140km/h and it is being improved to reach at the level of 200km/h in 2011. The improved environment of train operation speed which inevitably occurs owing to the operation of KTX on the existing line badly requires technology development such as testing and evaluating technology of factors hindering high speed of railway infrastructure including railway bridge, technology to ensure operation safety and technology to evaluate structure stability. Comparing dynamic numerical interpretation for railway truss bridge and load of design standard by using dynamic response measurement and analysis for the railway truss bridge currently in use, this study established the improvement program to ensure the lateral dynamic safety of truss bridge with the increased speed of train.