• Title/Summary/Keyword: Large Fire

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내화피복 강재의 내화성능 평가 예측에 관한 연구

  • Seong, Si-Chang
    • Fire Protection Technology
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    • s.17
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    • pp.5-9
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    • 1994
  • With a rapid development of economy, more high-rise buildings are being constructed in large cities than before. As a result steel members such as beams, columns make a great role of the building construction, and the need of them to be protected to have enough fire resistance is in-creasing . But conducting a real fire test to all the members is almost impossible. So prior to do conduct a real fire test of the protected steel members, evaluating the fire resistant rating of them by means of their specific properties might be economical things. This study is aimed to introduce the fire resistant rating of protected steel members without a real fire test through the related studies and data.

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Large scale fire test on a composite slim-floor system

  • Bailey, C.G.
    • Steel and Composite Structures
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    • v.3 no.3
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    • pp.153-168
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    • 2003
  • This paper discusses the results and observations from a large-scale fire test conducted on a slim floor system, comprising asymmetric beams, rectangular hollow section beams and a composite floor slab. The structure was subjected to a fire where the fire load (combustible material) was higher that that found in typical office buildings and the ventilation area was artificially controlled during the test. Although the fire behaviour was not realistic it was designed to follow as closely as possible the time-temperature response used in standard fire tests, which are used to assess individual structural members and forms the bases of current fire design methods. The presented test results are limited, due to the malfunction of the instrumentation measuring the atmosphere and member temperatures. The lack of test data hinders the presentation of definitive conclusions. However, the available data, together with observations from the test, provides for the first time a useful insight into the behaviour of the slim floor system in its entirety. Analysis of the test results show that the behaviour of the beam-to-column connections had a significant impact on the overall structural response of the system, particularly when the end-plate of one of the connections fractured, during the fire.

An Experimental Study on the Behavior of Liquid Fuel Flames in the Confined Space (밀폐공간에서 액체연료 화염의 거동에 관한 실험적 연구)

  • Jeon, Kil Song;Hwang, Ji Hyun;Lee, Tea Won
    • Journal of the Korean Society of Safety
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    • v.36 no.2
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    • pp.87-93
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    • 2021
  • Modern society shows rapid growth that is different from that of the development of existing technologies. The development of these technologies has led to the tendency of buildings to become dense, large and advancing. Regarding fire hazards, the possibility of large-scale fires causing fatal damage, due to the rapid spread of fire, increases. Therefore, for this reason, fire defense, i.e. detection and fire extinguishing facilities, in buildings are essential and well applied. But there are always limitations to that. Based on this reason, we would like to suggest the introduction of a new concept of a fire safety system. The method presented here is not only to use a single system for fire detection and fire extinguishing systems but to jointly use it in the environment and energy management fields within the building. However, an important step is required before introducing a system of these technologies. The fire extinguishing method proposed by this system is a method of extinguishing by blocking oxygen flowing into the space where the fire occurred. However, a sufficient basis is needed for this system to be applied in practice. Therefore, in this study, we intend to conduct a preliminary experiment to introduce the new concept of fire detection and extinguishing. The experiment used ethanol with a relatively simple combustion reaction and a high possibility of complete combustion. As a result, it was confirmed how the internal values changed during a fire using ethanol. Resultingly, we obtained the internal oxygen concentration and internal environmental changes according to the initial flame size. Lastly, the data accumulated in this study can be used as data for application in an automatic fire extinguishing system.

A Study on the Feasibility Analysis of Large Scale Research Project (대규모 연구 프로젝트 타당성 분석에 관한 연구)

  • Lee, Hong-Cheol;Hwang, In-Ju;Kim, Tae-Hyung
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.334-339
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    • 2008
  • Nowadays national research and development fund is continuously increased. And the evaluation on the feasibility of R&D budget investment was carried out. Through this study it was possible that a business feasibility evaluation of large scale research project. Also the benefit of research project about large scale plant(A plant) is $2.67{\sim}3.76$ times of research funds, and the R&D fund pay-back period is $6{\sim}8$ years. And also there is employment effect as $1,200{\sim}2,200$ every year, and $22,000{\sim}35,000$ within 20 years after research project.

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An experimental study on fire resistance of medical modular block

  • Kim, Hyung-Jun;Lee, Jae-Sung;Kim, Heung-Youl;Cho, Bong-Ho;Xi, Yunping;Kwon, Ki-Hyuck
    • Steel and Composite Structures
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    • v.15 no.1
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    • pp.103-130
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    • 2013
  • Fire performance and fire safety of high-rise buildings have become major concerns after the disasters of World Trade Center in the U.S. in 2001 and Windsor tower in Spain in 2005. Performance based design (PBD) approaches have been considered as a better method for fire resistance design of structures because it is capable of incorporating test results of most recent fire resistance technologies. However, there is a difficulty to evaluate fireproof performance of large structures, which have multiple structural members such as columns, slabs, and walls. The difficulty is mainly due to the limitation in the testing equipment, such as size of furnace that can be used to carry out fire tests with existing criteria like ISO 834, BS 476, and KS F 2257. In the present research, a large scale calorie meter (10 MW) was used to conduct three full scale fire tests on medical modular blocks. Average fire load of 13.99 $kg/m^2$ was used in the first test. In the second test, the weighting coefficient of 3.5 (the fire load of 50 $kg/m^2$) was used to simulate the worst fire scenario. The flashover of the medical modular block occurred at 62 minutes in the first test and 12 minutes in the second test. The heat resistance capacity of the external wall, the temperatures and deformations of the structural members satisfied the requirements of fire resistance performance of 90 minutes burning period. The total heat loads and the heat values for each test are calculated by theoretical equations. The duration of burning was predicted. The predicted results were compared with the test results, and they agree quite well.

Analysis of Burn Severity in Large-fire Area Using SPOT5 Images and Field Survey Data (SPOT5영상과 현장조사자료를 융합한 대형산불지역의 피해강도 분석)

  • Won, Myoungsoo;Kim, Kyongha;Lee, Sangwoo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.2
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    • pp.114-124
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    • 2014
  • For classifying fire damaged areas and analyzing burn severity of two large-fire areas damaged over 100 ha in 2011, three methods were employed utilized supervised classification, unsupervised classification and Normalized Difference Vegetation Index (NDVI). In this paper, the post-fire imageries of SPOT were used to compute the Maximum Likelihood (MLC), Minimum Distance (MIN), ISODATA, K-means, NDVI and to evaluate large-scale patterns of burn severity from 1 m to 5 m spatial resolutions. The result of the accuracy verification on burn severity from satellite images showed that average overall accuracy was 88.38 % and the Kappa coefficient was 0.8147. To compare the accuracy between burn severity and field survey at Uljin and Youngduk, two large fire sites were selected as study areas, and forty-four sampling plots were assigned in each study area for field survey. The burn severities of the study areas were estimated by analyzing burn severity (BS) classes from SPOT images taken one month after the occurrence of the fire. The applicability of composite burn index (CBI) was validated with a correlation analysis between field survey data and burn severity classified by SPOT5, and by their confusion matrix. The result showed that correlation between field survey data and BS by SPOT5 were closely correlated in both Uljin (r = -0.544 and p<0.01) and Youngduk (r = -0.616 and p<0.01). Thus, this result supported that the proposed burn severity analysis is an adequate method to measure burn severity of large fire areas in Korea.

An optimized deployment strategy of smart smoke sensors in a large space

  • Liu, Pingshan;Fang, Junli;Huang, Hongjun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.11
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    • pp.3544-3564
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    • 2022
  • With the development of the NB-IoT (Narrow band Internet of Things) and smart cities, coupled with the emergence of smart smoke sensors, new requirements and issues have been introduced to study on the deployment of sensors in large spaces. Previous research mainly focuses on the optimization of wireless sensors in some monitoring environments, including three-dimensional terrain or underwater space. There are relatively few studies on the optimization deployment problem of smart smoke sensors, and leaving large spaces with obstacles such as libraries out of consideration. This paper mainly studies the deployment issue of smart smoke sensors in large spaces by considering the fire probability of fire areas and the obstacles in a monitoring area. To cope with the problems of coverage blind areas and coverage redundancy when sensors are deployed randomly in large spaces, we proposed an optimized deployment strategy of smart smoke sensors based on the PSO (Particle Swarm Optimization) algorithm. The deployment problem is transformed into a multi-objective optimization problem with many constraints of fire probability and barriers, while minimizing the deployment cost and maximizing the coverage accuracy. In this regard, we describe the structure model in large space and a coverage model firstly, then a mathematical model containing two objective functions is established. Finally, a deployment strategy based on PSO algorithm is designed, and the performance of the deployment strategy is verified by a number of simulation experiments. The obtained experimental and numerical results demonstrates that our proposed strategy can obtain better performance than uniform deployment strategies in terms of all the objectives concerned, further demonstrates the effectiveness of our strategy. Additionally, the strategy we proposed also provides theoretical guidance and a practical basis for fire emergency management and other departments to better deploy smart smoke sensors in a large space.