• Title/Summary/Keyword: Local fire

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Development of Large Fire Judgement Model Using Logistic Regression Equation (로지스틱 회귀식을 이용한 대형산불판정 모형 개발)

  • Lee, Byungdoo;Kim, Kyongha
    • Journal of Korean Society of Forest Science
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    • v.102 no.3
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    • pp.415-419
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    • 2013
  • To mitigate forest fire damage, it is needed to concentrate suppression resources on the fire having a high probability to become large in the initial stage. The objective of this study is to develop the large fire judgement model which can estimate large fire possibility index between the fire size and the related factors such as weather, terrain, and fuel. The results of logistic regression equation indicated that temperature, wind speed, continuous drought days, slope variance, forest area were related to the large fire possibility positively but elevation has negative relationship. This model may help decision-making about size of suppression resources, local residents evacuation and suppression priority.

A Numerical Study on the Thermo-mechanical Response of a Composite Beam Exposed to Fire

  • Pak, Hongrak;Kang, Moon Soo;Kang, Jun Won;Kee, Seong-Hoon;Choi, Byong-Jeong
    • International journal of steel structures
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    • v.18 no.4
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    • pp.1177-1190
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    • 2018
  • This study presents an analytical framework for estimating the thermo-mechanical behavior of a composite beam exposed to fire. The framework involves: a fire simulation from which the evolution of temperature on the structure surface is obtained; data transfer by an interface model, whereby the surface temperature is assigned to the finite element model of the structure for thermo-mechanical analysis; and nonlinear thermo-mechanical analysis for predicting the structural response under high temperatures. We use a plastic-damage model for calculating the response of concrete slabs, and propose a method to determine the stiffness degradation parameter of the plastic-damage model by a nonlinear regression of concrete cylinder test data. To validate simulation results, structural fire experiments have been performed on a real-scale steel-concrete composite beam using the fire load prescribed by ASTM E119 standard fire curve. The calculated evolution of deflection at the center of the beam shows good agreement with experimental results. The local test results as well as the effective plastic strain distribution and section rotation of the composite beam at elevated temperatures are also investigated.

Modelling of the fire impact on CONSTOR RBMK-1500 cask thermal behavior in the open interim storage site

  • Robertas Poskas;Kestutis Rackaitis;Povilas Poskas;Hussam Jouhara
    • Nuclear Engineering and Technology
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    • v.55 no.7
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    • pp.2604-2612
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    • 2023
  • Spent nuclear fuel and long-lived radioactive waste must be carefully handled before disposing them off to a geological repository. After the pre-storage period in water pools, spent nuclear fuel is stored in casks, which are widely used for interim storage. Interim storage in casks is very important part in the whole cycle of nuclear energy generation. This paper presents the results of the numerical study that was performed to evaluate the thermal behavior of a metal-concrete CONSTOR RBMK-1500 cask loaded with spent nuclear fuel and placed in an open type interim storage facility which is under fire conditions (steady-state, fire, post-fire). The modelling was performed using the ANSYS Fluent code. Also, a local sensitivity analysis of thermal parameters on temperature variation was performed. The analysis demonstrated that the maximum increase in the fuel load temperatures is about 10 ℃ and 8 ℃ for 30 min 800 ℃ and 60 min 600 ℃ fires respectively. Therefore, during the fire and the post-fire periods, the fuel load temperatures did not exceed the 300 ℃ limiting temperature set for an RBMK SNF cladding for long-term storage. This ensures that fire accident does not cause overheating of fuel rods in a cask.

Evaluation of Design Fire Curves for Single Combustibles in a Cinema Complex (복합영상관 단일 가연물의 디자인 화재곡선 평가)

  • Jang, Hyo-Yeon;Hwang, Cheol-Hong;Oh, Chang Bo;Nam, Dong-Gun
    • Fire Science and Engineering
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    • v.34 no.3
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    • pp.18-27
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    • 2020
  • An actual fire test was performed on single combustibles placed in a local cinema complex, and quantitative differences in the maximum heat release rate (HRR) and fire growth rate were investigated based on the design fire curve methods (i.e., the general and 2-stage methods). In terms of combustible use and fire load, a total of 12 combustibles were selected, classified into cinema lounge and movie theater. It was found that the maximum HRR and fire growth rate determined using the two-stage method were quantitatively different from those of the general method. The application of the two-stage method, which can be used to determine the fire growth rate of the initial fire stage more precisely, could be useful in accurately predicting the activation time of fire detectors and fire-extinguishing facilities, as well as the available safe egress time (ASET) and required safe egress time (RSET).

Analysis of the Relationship between Landform and Forest Fire Severity (지형과 산불피해도와의 관계 분석)

  • Lee, Byung-Doo;Won, Myoung-Soo;Jang, Kwang-Min;Lee, Myung-Bo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.1
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    • pp.58-67
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    • 2008
  • Topography factors, as homeostasis variables at forest fire, affect the formation of fuel load patterns, atmospheric phenomena and forest fire behavior. Examination of the correlation between landforms and fire severity is important to decision making for fire hazard analysis and fighting strategies. In this study, fire severity was analyzed using Normalized Burn Ratio(NBR) derived from pre- and post-fire Landsat TM/+ETM images and landform were classified based on Topographic Position Index(TPI) in Samcheok(2000), Cheongyang(2002), and Yangyang(2005) forest fire regions. F-tests and Duncan's multi-range test between landform and fire severity showed that fire severities of headwater, high ridges, and upper slopes is higher than ones of local ridges, midslope ridges, and plains. Fire severity were more sensitive in coniferous forest than broadleaf forests.

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Investigating the Effect of Prior Damage on the Post-earthquake Fire Resistance of Reinforced Concrete Portal Frames

  • Ronagh, Hamid Reza;Behnam, Behrouz
    • International Journal of Concrete Structures and Materials
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    • v.6 no.4
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    • pp.209-220
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    • 2012
  • Post-earthquake fire (PEF) can lead to a rapid collapse of buildings that have been partially damaged as a result of a prior earthquake. Almost all standards and codes for the design of structures against earthquake ignore the risk of PEF, and thus buildings designed using those codes could be too weak when subjected to a fire after an earthquake. An investigation based on sequential analysis inspired by FEMA356 is performed here on the immediate occupancy (IO), life safety (LS) and collapse prevention (CP) performance levels of two portal frames, after they are pushed to arrive at a certain level of displacement corresponding to the mentioned performance level. This investigation is followed by a fire analysis of the damaged frames, examining the time taken for the damaged frames to collapse. As a point of reference, a fire analysis is also performed for undamaged frames and before the occurrence of earthquake. The results indicate that while there is minor difference between the fire resistances of the fire-alone situation and the frames pushed to the IO level of performance, a notable difference is observed between the fire-alone analysis and the frames pushed to arrive at LS and CP levels of performance and exposed to PEF. The results also show that exposing only the beams to fire results in a higher decline of the fire resistance, compared to exposing only the columns to fire. Furthermore, the results show that the frames pushed to arrive at LS and CP levels of performance collapse in a global collapse mode laterally, whereas at the IO level of performance and fire-alone situation, the collapse mechanism is mostly local through the collapse of beams. Whilst the investigation is conducted for a certain class of portal frames, the results confirm the need for the incorporation of PEF into the process of analysis and design, and provide some quantitative measures on the level of associated effects.

Study on the Comparative Consideration of the Operative System of the Overseas Volunteer Fire Department (해외 의용소방대 활동의 운영체계 비교 고찰에 관한 연구)

  • Kim, Hyeong-Do;Lee, Si-Young
    • Fire Science and Engineering
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    • v.31 no.6
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    • pp.99-106
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    • 2017
  • This research investigated the improvement plan for Korean Volunteer Fire Department through comparative consideration of overall operation system of Japanese and U.S. Volunteer Fire Department. For this, the researcher utilized descriptive approach according to documentary survey method including relevant academic essay, advanced research report, national institution publication, fire fighting-related books, textbook for new comers of Japanese fire department, and overseas training report, etc., and suggested an improvement plan for efficient operation of Korean Volunteer Fire Department. Research results are, first, enhance the community spirit of local community and establish of the status of Volunteer Fire Department. second, enlarge the scope of the work of Volunteer Fire Department to rescue, emergency medical services. third, organize task force team which is in charge of professional field education and training for Volunteer Fire Department. fourth, improve individual reward system and establishment of Volunteer Fire Department's identity and reinforce financial support. The researcher expects the research results can be utilized as the basic materials for the development of Korean Volunteer Fire Department, henceforth.

A Study on the Revitalization Method of the Korean Volunteer Fire Brigade (한국의용소방대의 활성화 방안에 관한 연구)

  • Lee, Jeom-Dong;Yoon, Myong-O;Choi, Don-Mook
    • Fire Science and Engineering
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    • v.22 no.4
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    • pp.95-104
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    • 2008
  • It is essential that the operational system of volunteer fire brigade (VFB) playing a important role in the local disaster prevention should be effectively improved to live in safety by protecting life and property of inhabitants from a disaster. The results of this research showed that most of volunteering members of fire brigade was highly satisfied with their works and thus they voluntarily did volunteer activities. It was also found that the development of the professional education program and training course about disaster prevention should be required because members of the volunteer fire brigade lacked expertise about the disaster prevention. Moreover, in order to activate and expand VFB, the establishment of the fundamental ideology about the activities of VFB, the introduction of effective selection examination system for the VFB and the creation of department fully responsible for the management of the VFBs should be necessary as well.

Numerical analysis on the behaviour of reinforced concrete frame structures in fire

  • Dzolev, Igor M.;Cvetkovska, Meri J.;Ladinovic, Dorde Z.;Radonjanin, Vlastimir S.
    • Computers and Concrete
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    • v.21 no.6
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    • pp.637-647
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    • 2018
  • Numerical approach using finite element method has been used to evaluate the behaviour of reinforced concrete frame structure subjected to fire. The structure is previously designed in accordance with Eurocode standards for the design of structures for earthquake resistance, for the ductility class M. Thermal and structural response are obtained using a commercially available software ANSYS. Temperature-dependent nonlinear thermal and mechanical properties are adopted according to Eurocode standards, with the application of constitutive model for the triaxial behaviour of concrete with a smeared crack approach. Discrete modelling of concrete and reinforcement has enabled monitoring of the behaviour at a global, as well as at a local level, providing information on the level of damage occurring during fire. Critical regions in frame structures are identified and assessed, based on temperatures, displacements, variations of internal forces magnitudes and achieved plastic deformations of main reinforcement bars. Parametric analyses are conducted for different fire scenarios and different types of concrete aggregate to determine their effect on global deformations of frame structures. According to analyses results, the three-dimensional finite element model can be used to evaluate the insulation and mechanical resistance criteria of reinforced concrete frame structures subjected to nominal fire curves.

Experience of a Disaster Medical Assistant Team activation in the fire disaster at Jecheon sports complex building: limitation and importance of rescue (제천 스포츠복합건물 화재 재난에서의 권역재난의료지원팀 활동 경험 고찰: 한계점과 구조의 중요성)

  • Jung, Seung Gyo;Kim, Yoon Seop;Kim, Oh Hyun;Lee, Kang Hyun;Kim, Kwan-Lae;Jung, Woo Jin
    • Journal of The Korean Society of Emergency Medicine
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    • v.29 no.6
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    • pp.585-594
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    • 2018
  • Objective: This study was designed to report on the progress of the fire at Jecheon sports complex and to assess the adequacy of Disaster Medical Assistant Team (DMAT)'s activities in response to the fire disaster. Methods: We conducted a retrospective review based on camera recordings and medical records that were recorded at the disaster site for assessment of activities. We cooperated with firefighters, police officers, local hospital medical staffs and public health personnel in Jecheon in order to classify patients in the disaster field and to understand the patients' progress. Results: At 15:53, the first request for emergency rescue came to the 119 general emergency call center, and a request for DMAT activation came at 16:28. DMAT arrived at the site at 17:04 and remained active until the following day at 00:43. The total number of casualties was 60, including 27 minimal (Green) patients, 29 expectant (Black) patients, three delayed (Yellow) patients, and one immediate (Red) patient. There were 32 patients who received on-site care by DMAT. Two patients were transferred from a local hospital to Wonju Severance Christian Hospital for hyperbaric oxygen therapy. Conclusion: Twenty-nine victims were found in the sports complex building, and there were 31 mildly to moderately injured patients in this fire disaster. The main cause of death was thought to be smoke suffocation. Although DMAT was activated relatively quickly, it was not able to provide effective activity due to the late rescue and difficulty with fire suppression.