• Proceedings of the KSR Conference
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• 2007.05a
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• pp.605-613
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• 2007

In order to overcome the difficulties of quantitative risk analysis such as complexity of model, we propose a systematic methodology for risk quantification of railway system which consists of 6 steps: The identification of risk factors, the determination of major scenarios for each risk factor by using event tree, the development of supplementary fault trees for evaluating branch probabilities, the evaluation of event probabilities, the quantification of risk, and the analysis in consideration of accident situation. In this study, in order to address the feasibility of the propose methodology, this framework is applied to the prototype risk model of nation-wide railway level crossings. And the quantification result based on the data of 2005 in Korea will also be presented.

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.342-348
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• 2008

This paper defines the Safety Management System (SMS) based on the rail safety act and surveys the status of the English rail SMS and International Civil Aviation Organization (ICAO) SMS and OHSAS18001 SMS. Through the analysis of the domestic rail operators' safety management regulations and the results of the universal rail safety audit, the status and problems of domestic rail operators' SMS are investigated and the improvement scheme are derived. First, to establish the continual improvement system for SMS, the instruction which describe the detailed continual improvement method for each steps of SMS including management review by CEO shall be established. Second, to settle the risk management based SMS, converting the rail operators mind and establishing the supply system of safety risk operating model and basic data for the risk analysis and safety evaluation and including the precise requirement for the risk management in the related instruction should be conducted.

• Tunnel and Underground Space
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• v.17 no.4
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• pp.322-331
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• 2007

Hundreds of rock slopes are constructed along the road, highway and railroad in mountainous Kangwon province and managed by each authorities concerned. It is practically not possible to carry out detailed rock slope investigation owing to the tremendous number of slopes and budgetary limit. Therefore, it is reasonable to perform a step-by-step investigation consisted of basic and detailed survey program and practical rock slope hazard assesment method for person in charge is strongly required. Through the development and application of KSMR (Korean Slope Mass Rating), it was found that KSMR could be practically used as an alternative of SMR though the number of inputs were reduced. In addition, the difference of hazard assessment between KSMR and experts decreased in case of considering the height of slope.

• Journal of the Korean Society for Railway
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• v.11 no.6
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• pp.530-535
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• 2008

After train fire accident in Daegue, many research on train fire safety improvement have been carrying out. Since many alternative fire safety measures can be applied in our railway system, the effect of the each safety measure must be quantified prior to the safety investment. In order to estimate the effects of each safety measure quantitatively, fault trees and event trees are constructed in this study. Results can be applied for cost-benefit analysis or sensitivity analysis for safety measures in risk assessment process.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.502-505
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• 2011

국내 철도터널 방재관련 법규에는 정량적 위험성 분석을 수행하여 주요한 방재시설의 설치 여부 및 규모를 결정하도록 규정하고 있으나 위험성 분석을 수행하기 위해 필요한 세부 기준에 대해서는 정해진 것이 없어 이에 대한 검토가 필요한 것으로 판단된다. 따라서 본 연구에서는 국내 철도터널의 정량적 위험도 평가 사례를 수집하고 이를 분석함으로서 철도터널 방재시설의 위험도 감소효과를 분석하고자 하였다. 정량적 위험도 평가사례분석 결과 Risk Index에 가장 크게 영향을 미치는 인자는 터널의 경사도로 분석되었으며, 방재설비 중 대피통로와 배연설비가 위험도 저감효과가 가장 높은 것으로 분석되었다.

• Proceedings of the KSR Conference
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• 2006.05b
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• pp.67-71
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• 2006

• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.532-538
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• 2006

The railway human reliability analysis(R-HRA) plays a role of identifying and assessing human failure events in the framework of the probabilistic risk assessment(PRA) of the railway systems. This study introduces a case study that was performed to select an appropriate R-HRA method. Three HRA methods were considered in the case study: (1) the K-MRA(THERP/ASEP-based) method, (2) the HEART method, (3) the RSSB-HRA method. Two case events were selected based on the review of the railway incidents/accidents, which include (1) a real-end collision event, which occurred on the railway between the Gomo and Kyungsan stations in 2003, (2) the signal passed at danger(SPAD) events, which are caused from a variety of factors. The three HRA methods were applied to both case events, and then the strengths and limitations of each method were derived and compared with each other from the viewpoint of the applicability of a HRA method to the railway industry.

• Journal of the Korean Society for Railway
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• v.11 no.2
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• pp.158-164
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• 2008

Abstract Infiltration of rainfall that may lead to reduce resistance force due to reduction of matric suction and to increase driving force due to increase of self weight makes the slope fail. There are many specifications to make slope stable based on factor of safety. Although result of slope stability analysis satisfy the specifications, slope failures triggered by rainfall are frequently occurred in reality because slope stability analysis cannot consider uncertainty of each soil properties. This is why conventional analysis has limitation and development of alternative method is needed. So it is suggested to adopt the reliability analysis rather than design based on factor of safety into designing safer structure. Through the evaluation of handicaps for the factor of safety based design, calculation of soil properties by site investigation, and reliability analysis considering distribution of each soil properties, distribution of failure probability in railway slope is obtained. Then, Risk assessment of slopes in Korean railway is executed from the results. Damage loss and incoming loss are considered as the loss. Using these results, it is possible to make proper countermeasure or efficient maintenance.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.342-347
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• 2009

Failure Mode Effects and Criticality Analysis (FMECA) is one of most widely used methods in modern engineering system to investigate potential failure modes and its severity upon the system. While performing FMECA, the experts evaluates criticality and severity of each failure mode and visualize the risk level matrix putting those indices to column and row variable respectably. Which results uncertainty in the result. In order to handle the uncertainty and conclude risk level matrix, this paper proposes a new FMECA procedure using minimal cut set (MCS) and fuzzy theory. Severity is calculated by proposed structural importance while criticality is determined by typical equipment failure rate data from IEEE Std 493. Finally, the risk level is compounded of these indices.

• Journal of the Korean Society for Railway
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• v.11 no.4
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• pp.404-409
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• 2008

This paper consists largely of two parts: the first part introduces the revised railway human reliability analysis (R-HRA) method which is to be used under the railway risk assessment framework, and the second part presents the features of a computer software which was developed for aiding the R-HRA process. The revised R-HRA method supplements the original R-HRA method by providing a specific task analysis guideline and a classification of performance shaping factors (PSFs) to support a consistent analysis between analysts. The R-HRA software aids the analysts in gathering information for HRA, qualitative error prediction including identification of external error modes and internal error modes, quantification of human error probability, and reporting the overall analysis results. The revised R-HRA method and software are expected to support the analysts in an effective and efficient way in analysing human error potential in railway event or accident scenarios.