• Title/Summary/Keyword: Structural Fires

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Analysis of the Effect of Forest Fires on the Mineralogical Characteristics of Soil (산불 영향에 따른 토층의 광물학적 특성 변화에 관한 연구)

  • Man-Il Kim;Chang-Oh Choo
    • The Journal of Engineering Geology
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    • v.33 no.1
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    • pp.69-83
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    • 2023
  • Forest fires increase the risk of subsequent soil erosion and mass movement in burned areas, even under rainfall conditions below landslide alert thresholds, by destroying plants and vegetation and causing changes to soil properties. These effects of forest fires can alter runoff in burned areas by altering soil composition, component minerals, soil water repellency, soil mass stability, and soil fabric. Heat from forest fires not only burns shallow organic matter and plants but also spreads below the surface, affecting soil constituents including minerals. This study analyzed X-ray diffraction and physical properties of topsoil and subsoil obtained from both burned and non-burned areas to identify the composition and distribution of clay minerals in the soil. Small amounts of mullite, analcite, and hematite were identified in burned soils. Vermiculite and mixed-layer illite/vermiculite (I/V) were found in topsoil samples from burned areas but not in those from non-burned areas. These findings show changes in soil mineral composition caused by forest fires. Expansive clay minerals increase the volume of soil during rainfall, degrading the structural stability of slopes. Clay minerals generated in soil in burned areas are therefore likely to affect the long-term stability of slopes in mountainous areas.

An Investigation on Fire Resistance Design of Tunnel Structures (주요 터널화재 사고사례 분석 및 국내 터널구조물 내화설계법 고찰)

  • Han, Sang-Hoon;Kim, Min-Suk;Lee, Choul-Ho
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.04a
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    • pp.341-344
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    • 2008
  • By investigating a series of catastrophic tunnel fires, this research aims to evaluate the fire resistance design method as applied to tunnel structures in Korea. It is shown that the current strategy is oriented towards smoke control and ventilation to reduce the loss of life. As structural collapse is not regarded, a general guide is proposed to obtain the fire safety.

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Study on Fire Resistance Performance According to Boundary Conditions for Beams Made of High-Strength Structural Steels Using Analytical Methods (경계조건에 따른 고강도 H형강 부정정 보부재의 해석적 내화성능 연구)

  • Kwon, In-Kyu
    • Fire Science and Engineering
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    • v.29 no.5
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    • pp.23-28
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    • 2015
  • Recently, structural materials have been developed to have high performance, and SM 520 has been developed and used for high-rise buildings. However, fires frequently occur in buildings, and the number of victims and amount of damage increase year by year. However, the evaluation of fire resistance performance for structural beams made of SM 520 is done with specimens made of ordinary structural steels with boundary conditions of a fixed beam, and the results are allowed for use in steel-framed buildings. This study analyzed the fire resistance performance of statistically indeterminate beams built with SM 520. The analysis used a fire engineering technique that includes mechanical and thermal data of SM 520 and heat transfer theory, and heat stress analysis was also conducted. The results from the analysis were compared with those from a statistically determinate beam made of ordinary structural steels.

Strength Characteristics of Passive Fire Protection Material Applied Structural Members on Fire Load (수동화재보호 재료가 적용된 구조부재의 화재하중에 대한 강도 특성)

  • Jo, Sang Chan;Yu, Seung Su;Seo, Jung Kwan
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.1
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    • pp.29-38
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    • 2022
  • In offshore installations, fires cause the structure to lose its rigidity and it leads to structural integrity and stability problems. The Passive Fire Protection (PFP) system slows the transfer rate of fire heat and helps prevent the collapse of structures and fatality. Especially, intumescent epoxy coating is widely used in the offshore industry, and not only is the material cost expensive, but it also takes a lot of time and cost for construction. Several studies have been conducted on the efficient application and optimal design of the PFP system. However, the mechanical properties and the strength of the PFP material have not been considered. In addition, researches on the correlation between the thickness of PFP and the structural behavior were insufficient. Therefore, this study aims to analyze the thermal and mechanical effects of the PFP on the structure when it is applied to the structural member. In particular, it is intended to resolve the change in strength characteristics of the structural members as the thickness of the PFP increases.

Consideration on Fire-prevention Facilities for Wooden Cultural Heritages (목조문화재 보존을 위한 소방시설에 대한 고찰)

  • Kim, Tae-Goo
    • 보존과학연구
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    • s.31
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    • pp.155-171
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    • 2010
  • Wooden cultural heritages have many factors of fires and structural characteristics vulnerable to the fire extinguishing. Also, they are surrounded with forests and so remote from fire stations, which make it difficult to handle it quickly when fires break out. Wooden cultural heritages made of wood materials belong to the general fire in a Class A. Taking characteristics such as a smoldering and a backfire from the that fire of wooden materials into consideration, extinguishing the fire by the cooling system is the most effective. If the fire can't be put out at the early stage, it is almost impossible to protect wooden cultural heritages from the fire, because wooden structures can be destroyed in a high temperature and in a short time and it takes around average 7 minutes to reach its peak of flames in the process of a fire. According to the geographical and environmental situation of the cultural heritages, currently, the fire-prevention facilities such as the auto fire detector for the prompt detection, the water mist fire suppression system for the 1st early and urgent fire suppression and the outdoor fire hydrant and the water curtain etc. for the 2nd full-scale suppression and the prevention of the fire gaining force are being installed for the wooden cultural heritages.

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Fire-Resistance Characteristics of Shield Tunnel Concrete Linings (쉴드터널 콘크리트 라이닝의 내화특성)

  • Park Hae Geun;Lee Myeong Sub;Jeon Sang Eun;Park Dong Kyu
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.32-35
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    • 2004
  • In recent years a number of catastrophic tunnel fires, the Euro tunnel, the Mont Blanc tunnel, the Tauem tunnel and the Gotthard tunnel, have occurred and inflicted serious damages to European countries. If a fire occurs in shield tunnels, the reinforced concrete segment linings playing as an important structural member is expected to damage severely and finally can be caused the collapse of tunnel. The purpose of this study is to evaluate the performance of concrete segment lining under heat exposure and to obtain information to assist a new technical approach to fighting fires in tunnels. In order to evaluate the fire-resistance performance of concrete segment by adding Polypropylene fibers, fire tests using the RABT heat-load curve is carried out. The temperature rise of this curve is very rapid up to $1200^{\circ}C$ within 5 minutes, and duration time of the $1200^{\circ}C$ exposure is 55 minutes. From the fire test, it was found that the explosive spalling was rapidly reduced by adding polypropylene fibers and this method is considered as an effective fireproof material to upgrade fire safety in tunnels economically.

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Temperature and Stress Analysis of Box Culvert in Fire (화재에 의한 지하공동구의 온도 및 응력해석)

  • Kim, Hyun-Jun;Im, Cho-Rong;Yoo, Hyeon-Kyeong;Chung, Chul-Hun
    • Journal of the Korean Society of Safety
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    • v.26 no.6
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    • pp.31-44
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    • 2011
  • This paper has presented a finite element analysis of structural behaviour of box culvert during and after fires. The fire tests were carried out in a furnace on RC slabs using the ISO 834 standard fire curve. The load capacity after cooling of the RC slab that was not loaded during the fire tests was evaluated by means of additional 3 points bending tests. In the past, stress-strain models of concrete under fire loading have been proposed by several researchers. Comparisons are made with the load-displacement relations of RC slabs after fire loading using the existing stress-strain models with temperature, such as Schneider, EUROCODE 2, Lie, Shi and Nan model. By comparing the load-displacement relations, Lie model was found to result in a maximum load about 2.0% higher than that of test. Based on the fire test results of RC slabs, this paper presents an extensive analytical study on the fire response of box culvert during and after fires.

The Analysis of Questionnaires About the investigation of fire and the task of fire fighting(Conducted chiefly by Fire Fighting employees of Kyonggi Province) (화재조사.진압임무 수행에 관한 설문조사 분석(경기도 소방공무원을 중심으로))

  • Gwon, Hyeon-Seok;Lee, Jae-Dong;Yun, Hyeok-Jung;Park, Gi-Hun
    • Journal of Korean Institute of Fire Investigation
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    • v.3 no.1
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    • pp.16-32
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    • 2003
  • Today, fires are becoming so catastrophic and complicated due to the industrialization and diversification of energy sources that it is getting more difficult to define the survey items in order to find out the causes and processes of the fire. As an organization of prevention, vigilance and putting out of the fire, Fire Fighting authorities are ultimately pursuing the system of fire fighting administration to protect human lives and their properties through establishment and performance of fire prevention policy based on the fire-related statistics they have gathered and prevention of future fires of the kind which can promote the safety of structural space. Thus, to facilitate the fire detection, it can be said that good understanding of the tasks of both investigation and putting out of the fire as being two axes has the greatest significance. For this study, textbooks from the organization of fire fighting and police, which are designed for the literature study on the investigation and putting out of fire, are used and for the demonstrative study, the conclusions have been reached by the analyses of the 64 questionnaires of three parts which were divided by fire investigation and fighting for three hundred and six governmental employees engaging in the above fields.

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Application of Deep Learning: A Review for Firefighting

  • Shaikh, Muhammad Khalid
    • International Journal of Computer Science & Network Security
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    • v.22 no.5
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    • pp.73-78
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    • 2022
  • The aim of this paper is to investigate the prevalence of Deep Learning in the literature on Fire & Rescue Service. It is found that deep learning techniques are only beginning to benefit the firefighters. The popular areas where deep learning techniques are making an impact are situational awareness, decision making, mental stress, injuries, well-being of the firefighter such as his sudden fall, inability to move and breathlessness, path planning by the firefighters while getting to an fire scene, wayfinding, tracking firefighters, firefighter physical fitness, employment, prediction of firefighter intervention, firefighter operations such as object recognition in smoky areas, firefighter efficacy, smart firefighting using edge computing, firefighting in teams, and firefighter clothing and safety. The techniques that were found applied in firefighting were Deep learning, Traditional K-Means clustering with engineered time and frequency domain features, Convolutional autoencoders, Long Short-Term Memory (LSTM), Deep Neural Networks, Simulation, VR, ANN, Deep Q Learning, Deep learning based on conditional generative adversarial networks, Decision Trees, Kalman Filters, Computational models, Partial Least Squares, Logistic Regression, Random Forest, Edge computing, C5 Decision Tree, Restricted Boltzmann Machine, Reinforcement Learning, and Recurrent LSTM. The literature review is centered on Firefighters/firemen not involved in wildland fires. The focus was also not on the fire itself. It must also be noted that several deep learning techniques such as CNN were mostly used in fire behavior, fire imaging and identification as well. Those papers that deal with fire behavior were also not part of this literature review.

Time-Temperature Curve for Fire Safety Assessment of Metropolitan Transit Tunnels (도시철도 터널구조체의 내화안정성 평가를 위한 표준시간-온도곡선 적용)

  • Won, Jong-Pil;Choi, Min-Jung;Lee, Su-Jin;Lee, Sang-Woo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.3
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    • pp.118-122
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    • 2010
  • The study presents a standard time-temperature curve to evaluate the fire performance of subway tunnel structures. The central subway section is 135km long in Korea, the fourth longest in the world. The number of subway tunnels has been increasing rapidly and fire risk is proportional to the tunnel length. However, an adequate time-temperature curve for subway tunnel fires does not exist. Therefore, we studied a proposed foreign fire design model for which the heat rate is based on the traffic, and we present an appropriate time-temperature curve for Korean subway tunnels. The ISO 834 curve was used as a fire design model and the temperature distribution in the tunnel was estimated using numerical analysis. This led to a proposal for effective measures against subway tunnel fires.