• Journal of Korean Society of Steel Construction
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• v.23 no.3
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• pp.283-294
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• 2011

The variation of temperature in the steel girder bridge by air temperature is measured. A correlation between the daily temperature range, the maximum and minimum temperatures of the day, and the temperature of the bridge are analyzed. With the statistical data from the Korea Meteorological Administration, the temperature correlations analyzed in this study is able to predict temperature variations between the upper flange and the lower flange which calculates the realistic displacement values of a movable support and an expansion joint in design.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.4
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• pp.57-65
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• 2009

This study is an evaluation of seismic fragility function using the HAZUS program for railway bridge systems, based on the results of previous research on seismic safety factor. First, a fragility function for each of the bridge members was evaluated according to the damage criteria and failure mode. Subsequently, bridge system fragility was evaluated using a fault tree to describe damage status. Finally, a fragility evaluation method for the bridge system was developed, based on the safety factor derived from the previous research.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.3
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• pp.317-327
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• 2001

In this paper, a relation to calculate design moments for reinforced concrete(RC) bridges constructed by movable scaffolding system(MSS) is introduced. Through the time-dependent analysis of RC bridges considering the construction sequence, the structural responses related to the member forces and deflections are reviewed, and a governing equation for determination of the design moment, which includes the creep deformation, is derived on the basis of the displacement-force condition at every constructuion stage. By using the relation, the design moment and its variation over time can easily be obtained only with the elastic analysis results without additional time-dependent analysis. In addition, correlation studies with the results by rigorous numerical analyses are conducts to verify the applicability of the introduced relation, and a more reasonable guideline for the determination of design moments is proposed on the basis of the obtained moment envelop.

• Magazine of the Korea Concrete Institute
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• v.10 no.5
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• pp.159-165
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• 1998

중트럭 통행으로 인한 철근콘크리트 교량바닥판의 열화는 교량구조물을 유지보수하는데 있어 심각한 문제 중 하나이며, 프리캐스트 바닥판을 이용한 교량바닥판의 시공 및 교체 방법이 실용적이며 효과적인 방법으로 인식되고 있다. 본 연구에서는 횡방향 ddusruf부에 종방향 프리스트레싱을 도입한 프리캐스트 바닥판의 모델을 제작하여 바닥판간 횡방향 연결부의 강성 평가 및 연결부의 피로 거동을 파악하기 위해서 피로실험을 수행하여 피로하중하에서의 휨강성의 변화, 균열발생 및 파괴하중 등을 측정하였다. 실험결과를 통해서 피로하중하에서 프리스트레스 프리캐스트 부재의 프리스트레스 효과를 평가하였으며, 현장타설에 의해서 시공되는 일반 RC 부재에 비해서 우수한 구조적 거동을 보여주는 적정량의 종방향 프리스트레스 크기를 결정하였다.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.158-158
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• 2011

통상 교량구조물은 차도부와 보도부 및 그 부속시설로서 난간 및 연석부 등으로 구성되는데, 자동차 전용도로의 경우 보도부가 설치되지 않게 되고, 국내의 국도 및 지방도상의 많은 교량이 차도부와 보도부의 별도의 구분이 없이 보행자가 연석부 위로 통행하거나 여의치 않을 경우 난간에 기대어 통행하는 경우가 일반적이어서 안전사고의 위험에 직접 노출되는 경우가 많다. 이에 국토해양부에서는 최근 "도로의 구조 및 시설기준에 관한 규칙"을 개정하여 국내의 보행자 관련 교통사고로 인한 사망자가 전체 교통사고 사망자의 약 절반을 차지하는 실정을 고려하여 보행자의 안전한 통행로 확보를 통해 보행공간의 근본적인 개선이 불가피한 실정임을 시사 하였다. 이에 국내에서는 교량 보도부의 확장에 대한 관심이 높은 실정이며, 현재 보도부 확장에 대한 시공이 활발하게 이뤄지고 있다. 그러나 기존 교량에 보도부를 신설 혹은 확장함에 있어서 보도부 부재의 설치 간격 및 필요한 앵커볼트의 수량 및 부재의 성능 평가에 대한 기준이 명확하게 이뤄지지 않은 상태에서 설치되어져 왔었다. 기존에 시공되던 H-형강의 브라켓 단면의 경우 브라켓 단면의 중량이 커서 안정성 및 시공성이 떨어지며 과다한 앵커볼트의 체결 및 브라켓 단면의 과다설계로 인한 공사기간 및 비용의 증대를 가져오는 문제점이 있었다. 이에 본 연구에서는 교량 보도부의 확장 및 신설에 있어서 보도부 부재의 설치간격의 적정성 및 브라켓의 최적화를 위한 브라켓의 성능평가 시험을 수행하였다. 브라켓의 성능평가 시험은 1차 2차 3차 시험으로 나누어 진행되었으며, 1차시험은 H-형강의 브라켓단면을 원형강관으로서의 대체 가능성을 확인하였고, 2차 시험에서는 원형강관의 브라켓 단면의 앵커볼트수량의 최적화에 대한 시험을 수행하였으며, 3차 시험은 최적화된 브라켓 단면에 프리스트레싱의 도입으로 반력 및 인발력의 감소효과를 확인하는 연구를 수행하였다. 본 연구의 수행결과 기존의 설계 및 시공방법이 과다 설계가 이뤄졌음을 판단하였고, 브라켓 단면의 최적화를 통하여 기존 시공방법에 비해 시공성, 안전성, 경제성을 높일수 있을 것으로 판단된다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.102-110
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• 2023

PSC-I girder bridges constitute the largest proportion among highway bridges in Korea. According to the precision safety diagnosis data for the past 10 years, approximately 41.3% of the PSC-I bridges have been graded as C. Furthermore, with the increase in the aging of bridges, preemptive management is becoming more important. Damage and deterioration to the deck and girder with a long replacement cylce can have considerable impacts on the service and deterioration of a bridge. In addition, the high rate of device damages, including expansion joints and bearings, necessitates an investigation into the influence of the device damage in the structural members of the bridge. Therefore, this study defined representative PSC-I girder bridges with single and multiple spans to evaluate heterogeneous damages that incorporate the damage of the bridge member and device with the deterioration of the deck. The heterogeneous damages increased a crack area ratio compared to the individual single damage. For the single-span bridge, the occurrence of bearing damage leads to the spread of crack distribution in the girder, and in the case of multi-span bridges, expansion joint damage leads to the spread of crack distribution in the deck. The research underscores that bridge devices, when damaged, can cause subsequent secondary damage due to improper repair and replacement, which emphasizes the need for continuous observation and responsive action to the damages of the main devices.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.194-197
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• 2006

교량의 고성능화, 고효율화 및 센서기술의 발전에 따라서 최근의 장대교량의 경우 교량에 각종 센서를 부착하여 상태를 실시간으로 교량의 상태를 계측하는 시스템이 개발되어 사용되고 있다. 하지만, 기존의 센서와 데이터 로거를 이용한 계측시스템은 높은 설치비가 요구되며 센서 설치비의 50%이상이 통신케이블에 관련된 비용이다. 본 논문에서는 설치비용 절감과 저렴한 유지관리비용 및 센서의 추가 및 교체가 손쉬운 무선기반의 계측시스템 개발에 관하여 논하고자 한다. 교량의 부재에 부착되어있는 센서들 사이 근거리 무선통신은 ZigBee를 이용한 무선통신네트워크를 구성하였으며, 교량과 교량관리소 사이의 장거리 통신에는 국내 휴대전화에 사용되고 있는 CDMA 통신망을 이용하여 데이터를 전송하는 방식을 취하고 있다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.3
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• pp.283-288
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• 2011

For the earthquake resistance design designer should provide that structural yielding process is principally designed with the ductile failure mechanism. In order to get the ductile failure mechanism for typical bridges, pier columns yielding should occur before that of connections. However domestic bridge design with unnecessary stiff substructure leads to unnecessary seismic loads and makes it difficult to get the ductile failure mechanism. Such a problem arises from the situation that earthquake resistant design is not carried out in the preliminary design step. In this study a typical bridge is selected as an analysis bridge and design strengths for connections and pier columns are determined in the preliminary design step by carrying out earthquake resistant design. It is shown through this procedure that it is possible to get the ductile failure mechanism with structural members determined by other design.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.25-28
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• 2008

Currently, the prefabricated bridge having the effects to reduce the term of works and the cost of construction is often studied and countries such as America have already developed members, the parts of it, and the technique of construction. In addition, they have supplied them to the fields. The study of prefabricated method of steel composite bridge, which has the precast deck - plate and main girder fixed by high tension bolt and can resist horizontal sheer, is being progressed. However, it is difficult to understand the characteristics of the prefabricated bridge's behavior when the superstructure of the prefabricated method is analyzed by applying to the analysis model of existing bridges. Therefore, this study has the purpose of understanding real structural behavior of prefabricated bridge through comparison and analysis between the structural analysis model reflecting the characteristics of the real prefabricated bridge's superstructure and real size experiment.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.6
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• pp.93-101
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• 2022

RC Slab bridges in Korea account for more than 70% of the total bridges for more than 20 years of service. As the number of aging structures increases, the importance of safety diagnosis and maintenance of structures increases. For highway bridges, cracks are a main cause of deck deterioration, which is very closely related to the decrease in bridge durability and service life. In addition, the damage rate of expansion joints and bearings accounts for approximately 73% higher than that of major members. Therefore, this study defined damage scenarios combined with devices damages and deck deterioration. The stress distribution and maximum stress on the deck were then evaluated using design vehicle load and daily temperature gradient for single and combined damage scenarios. Furthermore, this study performed damage-spread analysis and predicted condition ratings according to a deck deterioration model generated from the inspection and diagnosis history data of cracks. The heterogeneous damages combined with the member damages of expansion joints and bearings increased the rate of crack area and damage spread, which accelerated the time to reach the condition rating of C. Therefore, damage to bridge members requires proper and prompt repair and replacement, and otherwise it can cause the damage to bridge deck and the spread of the damage.