• Journal of Korean Society of Steel Construction
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• v.21 no.1
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• pp.45-53
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• 2009

More than 40% of railway bridges on the conventional lines in Korea consist of track-on-steel plate girder (TOSPG) bridges. This type of bridge is typically designed without considering seismic loadings, as most of them were built before 1970. The seismic performance of this particular type of bridge could be upgraded through various seismic retrofit schemes, and seismic risk assessment could play a key role in decision-making on the level of the seismic retrofit. This study performed a seismic risk assessment of TOSPG bridges in Korea. The seismic damage of several crucial components of TOSPG bridges--fixed bearings, free bearings, and piers--were probabilistically estimated, and their seismic fragility curves were developed. The probability that the components would exceed their predefined limit states was also calculated by combining the fragility curves and the seismic hazard function. The analysis showed that the piers of TOSPG bridges, which are made of plain concrete without rebars, have relatively low risk against seismic loadings in Korea. This is because the mass of the superstructures of TOSPG bridges is relatively small, and hence, the seismic loading being transferred to the piers is minimal. The line-type bearings typically used for TOSPG bridges, however, are exposed to a degree of seismic risk. Among the bearings, the probability of the free-end bearings and the fixed-end bearings exceeding the slight damage state in 50 years was found to be 12.78% and 4.23%, respectively. The gap between these probability values lessened towards more serious damage states. This study could effectively provide an engineering background for decision-making activities on the seismic retrofit of railway bridges.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.5
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• pp.809-822
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• 2018

A quantitative risk assessment has been introduced to quantitatively evaluate fire risk as a means of performance based fire protection design in the design of railway tunnel disaster prevention facilities. However, there are insufficient studies to examine the effect of various risk factors on the risk. Therefore, in this study, the risk assessment was conducted on the model tunnel in order to examine the effects of the evacuation start time delay and the fire growth curve on the quantitative risk assessment. As a result of the analysis of the scenario, the fatalities occurred mainly when escapes in the same direction as the direction of the fire smoke movement. In addition, after the FED exceeded 0.3, the maximum fatalities occurred within 10 minutes. In the range of relatively low risk, distance between cross passages, evacuation delay time and fire growth curve were found to affect the risk, but they were found to have little effect on the condition that the risk reached the limit. Especially, in this study, it was evaluated that the evacuation delay time reduction, fire intensity and duration reduction effect were not observed when the distance between cross passages was more than 1500 m.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.2
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• pp.117-125
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• 2015

Quantitative risk assessment (QRA) of railway is to create a variety of scenario and to quantify the degree of risk by a result of the product of accident frequency and accident. Quantitative risk Assessment is affected by various factors such as tunnel specifications, characteristics of the fire, and relation of smoke control and evacuation direction. So in this study, it is conducted that how the way of smoke control and the relation of smoke control and evacuation direction affect quantitative risk assessment with variables (the tunnel length (2, 3, 4, 5, 6 km) and the slope (5, 15, 25‰)). As the result, in a train fire at the double track tunnel (Area = $97m^2$), it is most efficient to evacuate to the opposite direction of smoke control regardless of the location of train in train fire. In addition, under the same condition, index risk in mechanical ventilation up to 1/10.

• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.13-20
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• 2010

Seismic risk assessment of railway bridges is an important issue for a transportation network, because loss of functionality of railway bridges could result in severe disruption of the railway line, as no redundant routing systems generally exist. Although many studies have been conducted by numerous researchers regarding fragility analyses of bridge structure, little or no studies have been done for fragility analyses of a class of bridge structures considering their geometric variability. This study performs a fragility analysis for Track-on Steel-Plate-Girder (TOSPG) railway bridges in Korea considering their span variability. Seismic fragility curves are developed for a series of bridges with different spans varying from 2 to 15. At last, the fragility curves for the whole TOSPG bridges in Korea are also developed using the total probability theorem. This study is expected to effectively contribute to the seismic risk assessment of railway lines, where a number of bridges are present.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.414-414
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• 2023

지구온난화로 인한 기후변화로 산불 발생이 증가하고 있는 추세이다. 이로 인해 무강우기간의 증가, 기온의 상승, 습도 감소 등의 문제가 발생하고 있다. 이중 기온의 상승과 습도의 감소는 산불과 큰 연관성이 있다. 따뜻하고 건조한 날씨는 토양수분의 감소로 이어지며, 이는 곧 식물의 활성도의 감소로 이어진다. 봄철 식물의 활성도가 감소하게 되면 자연스레 산불 발생 위험도가 높아지기 마련이다. 이러한 현상은 국내에서도 관찰 가능하다. 따뜻하고 건조한 국내 겨울철 날씨는 봄철 토양수분의 감소와 직결되며, 건조해진 토양수분으로 인해 봄철인 3월~5월 산불 발생 확률이 증가하게 된다. 실제로 최근 10년간 국내에서 산불이 많이 발생한 계절은 봄철이며, 산불로 인한 피해 면적 및 피해 금액이 가장 큰 기간도 봄철이다. 따라서 봄철 산불에 대한 각별한 주의가 요구 되어지고 있다. 본 연구에서는 국내 유역을 대상으로 산불 위험도 지수에 대한 평가를 진행하고자 한다. 이에 PRMS 모형을 이용해 봄철 토양수분을 모의하여 산불 위험도 지수와 토양수분의 상관성을 나타내고자 한다. 또한, 산불 발생 건수를 활용하여 산불 위험도 지수에 대한 적절성을 평가하고자 한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.371-371
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• 2022

하천관리지리정보시스템(RIMGIS)은 하천정보의 표준화 및 전산화를 통한 정보제공과 하천에 관련한 업무를 지원하기 위해 개발된 시스템으로 5개의 지방국토관리청에서 관리하고 있는 하천대장 및 부도, 구조물도 등의 다양한 하천 관련 정보를 정보화하여 인허가 및 하천기본계획 등의 하천업무를 신속하고 효율적으로 수행할 수 있도록 운영되고 있다. 국가 주요 기반시설을 생애주기 관점에서 관리하고 소요재원의 확보근거를 마련하고자 "지속 가능한 기반시설 관리 기본법"이 제정되었고 최근에 시행되었다. 이에 따라 국토안전관리원에서는 도로·철도·철도 하천 등과 같은 사회기반시설(15종)의 노후화에 대비하여 전략적인 투자와 관리방식 도입을 목적으로 인프라 총조사 사업을 진하천 등과 같은 사회기반시설(15종)의 노후화에 대비하여 전략적인 투자와 관리방식 도입을 목적으로 인프라 총조사 사업을 진행하고 관리를 위해서 기반터 시스템을 도입하였다. 하천관리지리정보시스템과 기반터 시스템은 하천 기반시설의 정보가 데이터베이스에서 다뤄진다는 점에서 유사하지만, 기반터 시스템은 하천관리지리정보시스템과 달리 유지관리 측면에 대한 필요한 보수 주기, 필요 예산 등과 같은 정보를 산정할 수 있도록 프레임워크가 구성되어 있다. 그러나 하천과 기반시설의 코드를 연결하는 작업들은 현재 상황에서는 미흡한 실정이고, 유지관리와 시설물의 노후화를 가속화하는 홍수와 침수피해 등을 전체적으로 고려할 수 있는 방안에 대한 연구도 미진한 상황이다. 이에 본 연구에서는 하천 기반시설의 유지관리를 위해 하천, 제방, 인명에 대한 위험지수를 고려한 잠재 인명피해 위험도와 잠재 홍수피해 위험도를 평가기준으로 설정하고 적용하였다. 또한 이를 포함시킨 투자우선순위 평가기법을 도입하여 감가상각과 위험요소 등을 고려할 수 있는 데이터베이스 구성 방안을 제시하고자 한다.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.121-129
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• 2011

This paper presents the methods to acquire the Safety Certificate from Independent Safety Assessment based on the IEC or EN standard which is commonly applied to railway system for Automatic Train Protection (ATP) system in accordance with ERTMS/ETCS Level 1 system. This also shows approach methods and relative activities for project lifecycle to accomplish and ensure the system requirements of ATP system, RAMS and system quality activities. These kind of activities for quality assurance of ATP system to obtain Safety Certificate could improve the quality of domestic railway system based on On-Board system of ERTMS/ETCS Level 1 and also contribute to the growth of railway business.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.277-280
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• 2007

CARA(CAncer Risk Assessment) 시스템은 과거의 데이터와 유전적 정보를 이용하여 암 발생 위험도가 높은 사람을 선별할 수 있는 시스템이다. 본 논문에서는 과거의 데이터와 유전적 정보를 가계도를 이용하여 표현하고 이를 암 발생 위험도 평가 시스템 개발에 활용한 CARA 시스템의 구현을 시스템의 인터페이스를 중심으로 설명한다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.3
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• pp.287-298
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• 2007

Recently, as the construction of new railway and the relocation of existing line increase, tunnel structures get longer. The railway fire accidents in long tunnel bring large damages of human life and disaster. The interest on safety in long tunnel has been growing and the safety standard for long tunnels is tightening. For that reason, at the planning stage of a long tunnel, the optimum design of safety facility for minimizing the risks and satisfying the safety standard is required. For the reasonable design of a long railway tunnel considering high safety, qualitative estimation for tunnel safely is required. In this study, QRA (Quantitative Risk Analysis) technique is applied to design of a long railway tunnel for assuring the safety function and estimating the risk of safety. The case study for safety design was carried out to verify the QRA technique for two railway tunnels.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1255-1263
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• 2008

A Safety Case is an railway organization's formal arrangement, through the provision of policies, resources and processes, to ensure the safety of its work activity within safety management system. An effective system helps the organization to identify and manage risks effectively. It allows an organization to demonstrate its capability in achieving its safety objectives and in meeting regulatory requirements. The purpose of this research is to give how to the risk assessments are described within Railway Safety Cases can be prepared and maintained to meet the criteria specified by the upcoming railway regulations. Through this research, we propose the elements of safety management system that include arrangements for the ongoing identification of hazards, assessment of risks and the implementation of necessary control measures.