• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.129-134
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• 2002

The seismic performance evaluation and retrofit process are very important for old bridge. If the result is not appropriate, a retrofit process requires. Among the various retrofit methods, this paper selects a seismic isolator and evaluates a seismic performance of bridge. In case of applied seismic isolators to bridge, it proved that seismic capacity is increased by isolators A period of bridge is increased, and a seismic response is decreased. A method of evaluation is capacity spectrum method. By means of a graphical procedure, capacity spectrum estimates a performance level of structure by comparing the capacity of structure with the demand of earthquake ground motion on the structure. The objective of this study is to compare a seismic performance of a non-seismic designed bridge and seismic isolated bridge and to verify a effect of seismic isolator

• 비파괴검사학회지
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• 제30권6호
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• pp.527-538
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• 2010

This paper presents a nondestructive evaluation approach for system identification (SID) of real railway bridges using field vibration test results. First, a multi-phase SID scheme designed on the basis of eigenvalue sensitivity concept is presented. Next, the proposed multi-phase approach is evaluated from field vibration tests on a real railway bridge (Wondongcheon bridge) located in Yangsan, Korea. On the steel girder bridge, a few natural frequencies and mode shapes are experimentally measured under the ambient vibration condition. The corresponding modal parameters are numerically calculated from a three-dimensional finite element (FE) model established for the target bridge. Eigenvalue sensitivities are analyzed for potential model-updating parameters of the FE model. Then, structural subsystems are identified phase-by-phase using the proposed model-updating procedure. Based on model-updating results, a baseline model and a nondestructive evaluation of test bridge are identified.

• 한국산업융합학회 논문집
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• 제9권3호
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• pp.199-206
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• 2006

Extraordinary displacement and vibration by heavy vehicle causes passengers to feel mental uncomfortableness and bridge to be damaged. To increase serviceability, the research on the human influence for vibration to happen at the bridge has been performed for a long time in oversea but it does not draw concern relatively in the domestic. The purpose of this research is to develop an evaluation method for vibration serviceability of continuous slab bridge. This research is focused on establishing theoretical method to assess vibration serviceability of bridge considering natural frequency, displacement, and acceleration since the criteria for the human responses to vibration is generally based on frequency band. By examining the characteristics of vibration serviceability which has been assessed with human response curve through field experiments as well as analytical study, the evaluation method of vibration serviceability for continuous slab bridges is proposed. Based on applications to the example of continuous slab bridge, the simple evaluation of vibration serviceability in the paper may be used in the initial step of design practice.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.75-80
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• 2000

Evaluation method of seismic performance has mainly used elastic spectrum analysis. This method has simplicity of analysis but deficiency of accuracy. And evaluation method of seismic performance using inelastic dynamic analysis reflects accurately inelasticity of material but hardly reflects site effects. This study suggested evaluation scheme of seismic performance for bridge structure using capacity spectrum method applied inelastic static analysis and standard design response spectrum of Korea Standard Specification for Highway Bridge. Two results, capacity spectrum method and inelastic dynamic analysis method, are very similar. As a result, this study appropriately supply both simplicity of analysis and accuracy of result.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.429-432
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• 2000

Test methods by hydraulic oil or vehicular live load have been used for structural evaluation of prototype bridge. However it has been reported that the use of hydraulic jack has some disadvantages for the view of safety and economy, and the complete structural evaluation through each loading state can not be accomplished blocks is presented to overcome those demerits. To verify the application and safely of the use of concrete weight blocks during each loading state, it is applied to prototype deteriorated bridge. As a result, it could be evaluated the structural behavior completely using the concrete weight blocks

• 한국신뢰성학회지:신뢰성응용연구
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• 제13권4호
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• pp.241-252
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• 2013

Because of financial and safety concerns, there are needs for more accurate prediction of bridge behavior. Underestimation of the bridge load carrying capacity can have serious economic consequences, as deficient bridges must be repaired or rehabilitated. Therefore, the knowledge of the actual bridge behavior under live load may lead to a more realistic calculation of the load carrying capacity and eventually this may allow for more bridges to remain in service with or without minor repairs. The presented research is focused on the reliability evaluation of the actual load carrying capacity of existing bridges based on the field testing. Seventeen existing bridges were tested under truck load to confirm their adequacy of reliability. The actual response of existing bridge structures under live load is measured. Reliability analysis is performed on the selected representative bridges designed in accordance with AASHTO codes for bridge component (girder). Bridges are first evaluated based on the code specified values and design resistance. However, after the field testing program, it is possible to apply the experimental results into the bridge reliability evaluation procedures. Therefore, the actual response of bridge structures, including unintentional composite action, partial fixity of supports, and contribution of nonstructural members are considered in the bridge reliability evaluation. The girder distribution factors obtained from the tests are also applied in the reliability calculation. The results indicate that the reliability indices of selected bridges can be significantly increased by reducing uncertainties without sacrificing the safety of structures, by including the result of field measurement data into calculation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.359-366
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• 2009

This paper aims for analyzing the vibration serviceability of train by simply expressing its vertical vibration when it passes a railway bridge. For this purpose, bridge-train transfer function was derived and bridge-train interaction analysis was performed by using the derived function. The bridge-train transfer function was developed with the assumption that train is a single mass-spring system, and bridge-train interaction analysis was performed on simple beams of KTX passenger car. The vertical acceleration signals of passenger cars obtained from bridge-train interaction analysis were compared with them of cars obtained from the bridge-train transfer function. As a result, it could be estimated to express the vertical vibration inside the passenger car required for vibration serviceability evaluation by using the vertical vibration of bridges obtained from moving load analysis. Therefore, it may be possible to evaluate the vibration serviceability of railway bridges considering bridge-train interaction effect.

• 한국방재학회 논문집
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• 제8권2호
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• pp.7-21
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• 2008

홍수 시 세굴로 인한 교량 기초의 파괴는 국내외적으로 교량 붕괴의 첫 번째 원인이다. 본 연구에서는 수도권 지역의 실제 국도교량에 대하여 세굴 위험도 평가 및 등급화를 수행하였다. 30개소 교량을 선정하여 지반 시추조사를 포함한 현장조사, 설계 홍수량에 대한 교량세굴 해석, 그에 따른 교량기초의 지지력 평가 및 위험도 분석을 하였고, 이를 바탕으로 교량세굴 위험도를 등급화 하였다. 위험도 평가 결과 직접확대기초 교량 26개소 중 9개소 교량이 장래 세굴 위험 가능성이 있는 것으로 나타났고, 나머지 17개소 교량은 안정한 수준으로 나타났다 말뚝기초 교량 4개소 중 3개소의 교량이 유의할 만한 수준으로 지지력이 감소하는 것으로 평가되었다.

• 한국안전학회지
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• 제21권1호
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• pp.105-113
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• 2006

The footing of a bridge is a very essential part that support the whole load induced by the bridge itself and the traffic as well. However, once a bridge is built, the footing is buried under soil so the footing is invisible from outside. Therefore, the safety or condition of the footing is very difficult to estimate. Not only the length of the imbedded part of the footings but also the type of footings are unknown once the design record is gone. Some nondestructive techniques can be used to evaluate invisible part of the footings but the results have not been successful yet. Using GPR (Ground Penetrating Radar), which has been used for the nondestructive evaluation in military purposes, the condition assessment of the footings have been successfully conducted in this research. The field evaluation and laboratory tests have been conducted to find effective factors in the condition assessment of the footings. The equipment and basic theory of the GPR has been presented. The field test results show that the GPR can be successfully used for the safety evaluation of the footings. More test results and field data are needed for more precise evaluation of the footings.

• 한국항해항만학회지
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• 제35권9호
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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.