• 국제초고층학회논문집
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• 제10권4호
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• pp.323-334
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• 2021

Concrete structures may rarely collapse in fire incidents but fire induced damage to structural members is inevitable as a result of material degradation and thermal expansion. This requires certain repairing measures to be applied to restore the performance of post-fire members. A brief review on investigation of post-fire damage of concrete material and concrete structural members is presented in this paper, followed by a review of post-fire repair research regarding various types of repairing techniques (FRP, steel plate, and concrete section enlargement) and different type of structural members including columns, beams, and slabs. Particularly, the fire scenarios adopted in these studies leading to damage are categorized as three levels according to the duration of gas-phase temperature above 600℃ (t₆₀₀). The repair effectiveness in terms of recovered performance of concrete structural members compared to the initial undamaged performance has been summarized and compared regarding the repairing techniques and fire intensity levels. The complied results have shown that recovering the ultimate strength is achievable but the stiffness recovery is difficult. Moreover, the current fire loading scenarios adopted in the post-fire repair research are mostly idealized as constant heating rates or standard fire curves, which may have produced unrealistic fire damage patterns and the associated repairing techniques may be not practical. For future studies, the realistic fire impact and the system-level structural damage investigation are necessary.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.423-430
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• 2005

Fire accidents in underground space may bring much loss of lives as well as properties and result in catastrophic disasters. This study aimed to manufacture the high-temperature furnace capable of simulating fire scenarios (RABT and RWS) and carry out the preliminary fire tests to evaluate fire-induced damage in underground structures. Specimens used in the fire tests were the concrete segments generally used in shield TBM tunnels. The simulated fire scenario was set to the RABT curve that is the most representative fire scenario in underground space. From the fire tests, the spalling was estimated to reach approximately 20cm from the surface exposed to fire. In addition, from the observation of core specimens obtained after fire tests, the deteriorated zone of unspalled specimens amounted to approximately 10cm from the surface of spalling.

• 한국측량학회지
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• 제37권5호
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• pp.351-357
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• 2019

UAV (Unmanned Aerial Vehicle) images can be exploited for rapid forest fire damage assessment by virtue of UAV systems' advantages. In 2019, catastrophic forest fire occurred in Goseong and Sokcho, Korea and burned 1,757 hectares of forests. We visited the town in Goseong where suffered the most severe damage and conducted UAV flights for forest fire damage assessment. In this study, economic and rapid damage assessment method for forest fire has been proposed using UAV systems equipped with only a RGB sensor. First, forest masking was performed using automatic elevation thresholding to extract forest area. Then ExG (Excess Green) vegetation index which can be calculated without near-infrared band was adopted to extract damaged forests. In addition, entropy filtering was applied to ExG for better differentiation between damaged and non-damaged forest. We could confirm that the proposed forest masking can screen out non-forest land covers such as bare soil, agriculture lands, and artificial objects. In addition, entropy filtering enhanced the ExG homogeneity difference between damaged and non-damaged forests. The automatically detected damaged forests of the proposed method showed high accuracy of 87%.

• 한국화재소방학회논문지
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• 제15권1호
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• pp.116-126
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• 2001

과학적이고 합리적인 화재조사 및 수사를 위해서는 화재조사 전담부서의 설치가 시급하고, 화재조사원의 충분한 확보와 이들의 전문성 강화가 필요하며, 화재감식 연구시설의 확충이 절실히 요구된다. 또한 화재조사업무의 신뢰성 확보를 위해서는 화재피해산정을 정확히 하도록 최선을 다해야 하며, 대외발표창구를 일원화해야 할 것이다. 그리고 방화 및 실화범에 대한 사회적 관심이 너무 부족하였다. 앞으로 이에 대한 많은 연구와 제도적 개선이 필요하다고 본다. 집행유예의 선고시 부과할 수 있는 수강명령 등을 방화 및 실화범에게 적용하여 소방시설 및 안전교육 등을 받게 함으로써 재범을 방지하는 등의 사회적 노력과 예방 관리적 프로그램이 요망된다.

• Steel and Composite Structures
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• 제43권5호
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• pp.673-688
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• 2022

Post-earthquake fire is a major threat since most structures are designed allowing some damage during strong earthquakes, which will expose a more vulnerable structure to post-earthquake fire compared to an intact structure. A series of experimental research on steel-concrete composite beam-to-column joints subjected to fire after cyclic loading has been carried out and a clear reduction of fire resistance due to the partial damage caused by cyclic loading was observed. In this paper, by using ABAQUS a robust finite element model is developed for exploring the performance of steel-concrete composite joints in post-earthquake fire scenarios. After validation of these models with the previously conducted experimental results, a comprehensive numerical analysis is performed, allowing influential parameters affecting the post-earthquake fire behavior of the steel-concrete composite joints to be identified. Specifically, the level of pre-damage induced by cyclic loading is regraded to deteriorate mechanical and thermal properties of concrete, material properties of steel, and thickness of the fire protection layer. It is found that the ultimate temperature of the joint is affected by the load ratio while fire-resistant duration is relevant to the heating rate, both of which change due to the damage induced by the cyclic loading.

• 한국지반공학회논문집
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• 제21권5호
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• pp.171-177
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• 2005

지하공간에서의 화재는 인명 및 재산피해 뿐만 아니라 지하구조물에 심각한 손상을 발생시킨다. 이러한 화재로부터 구조물을 보호하기 위해서 화재에 의한 지하구조물 시공재료의 손상을 파악하는 것은 매우 중요한 사항이다. 본 연구에서는 화재에 의한 지하구조물의 손상을 파악하기 위하여 지하공간 화재모의시험 가열로를 제작하였고, 쉴드 TBM 콘크리트 세그먼트시편에 대하여 모의 화재실험을 수행하였다. 수행된 실험은 5분에 $1,200^{circ}C$에 도달하여 1시간동안 유지한 후 2시간에 걸쳐 소화되는 RABT곡선을 모사하였다. 시험체내에 설치된 온도센서로 확인한 결과, 화재면으로부터 약 20cm까지 폭렬이 발생하였다. 또한 시험이 완료된 블럭시편으로부터 채취된 코어시편에 수행된 물리$\cdot$화학적 실험을 통하여 폭렬면으로부터 약 l0cm까지 시공재료의 특성이 저하되었음을 확인하였다.

• Safety and Health at Work
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• 제8권1호
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• pp.42-48
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• 2017

Background: As one of the most frequently occurring accidents in a chemical plant, a fire accident may occur at any place where transfer or handling of combustible materials is routinely performed. Methods: In particular, a jet fire incident in a chemical plant operated under high pressure may bring severe damage. To review this event numerically, Computational Fluid Dynamics methodology was used to simulate a jet fire at a pipe of a compressor under high pressure. Results: For jet fire simulation, the Kemeleon FireEx Code was used, and results of this simulation showed that a structure and installations located within the shelter of a compressor received serious damage. Conclusion: The results confirmed that a jet fire may create a domino effect that could cause an accident aside from the secondary chemical accident.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.48-49
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• 2021

The purpose of evaluating the fire risk of a building is to predict damage or loss of life and property in unspecified circumstances and to minimize expected damage. The fire risk assessment for buildings in Korea analyzes fire risk according to performance-oriented design under the Enforcement Decree of the Fire Facilities Act and the Fire Causing Index under the Enforcement Decree of the Multi-Use Business Act. Fire risk analysis is mainly conducted by using fire statistics or analyzing the results of safety inspections of buildings. In the case of fire statistics, it is necessary to analyze the fire risk in consideration of the degree of fire damage in each number of fires, as all fires received by the fire department are collected. In addition, it is necessary to devise fire safety measures for buildings by predicting the number of casualties that may occur due to fires in each building. Accordingly, this study aims to analyze the characteristics of casualties by building use using the number of fires judged to have grown.

• 한국화재소방학회논문지
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• 제30권5호
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• pp.116-123
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• 2016

화재모델링을 이용한 목표 대상물의 열적 손상에 대한 정량적 위험성 평가방법이 검토되었다. 이를 위해 대표적인 화재모델로서 FDS가 사용되었으며, 특정 구획 내에서 화원 면적 변화에 따른 전기 케이블의 열적 손상과 관련된 확률이 평가되었다. 보수적 관점에서 적용되고 있는 '최대 손상임계 초과확률'과 손상시간의 정보가 포함된 '손상확률'이 체계적으로 비교되었다. 목표 대상물이 표면온도 및 열유속에 대한 최소 손상기준에 도달하는 순간에 열적 손상이 발생된다는 가정이 적용된 최대 손상임계 초과확률에 비해 본 연구에서 제안된 손상확률은 정량적 화재 위험성을 보다 현실적으로 평가할 수 있음을 확인하였다.

• 대한토목학회논문집
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• 제26권3C호
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• pp.219-228
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• 2006

본 연구에서는 화재시나리오에 따른 터널구조물의 시공재료별 단면손실과 폭렬현상을 파악하고자 터널구조물 시공재료별로 시험체를 제작한 후 모의 화재시험을 수행하였다. 시공재료별로 화재시험을 수행한 결과, 모든 시공재료에서 RABT 화재곡선보다 RWS 화재곡선에서 단면손실이 다소 크게 발생하였다. 특히, RWS 화재곡선에서 나타나는 $1,200^{\circ}C$ 이상의 고온으로 인한 융해는 시공재료의 단면손실에 주요한 영향요인으로 작용하였다. 철근 보강 구조물은 무근 구조물에 비해 단면손실이 적은 것으로 나타났다. 숏크리트의 경우 화재 시나리오에 따른 단면손실의 차이가 가장 크게 발생하였다. 가열시험 도중에 가열면을 실시간 관찰한 결과, RABT에서의 재료 손상은 폭렬과 탈락에 의해 발생한 반면 RWS에서는 초기에는 RABT와 유사하나 가열개시후 약 50분 이후의 재료 손상은 폭렬과 탈락이 아닌 융해에 의한 것을 알 수 있었다.