• 제목/요약/키워드: Force of fire

검색결과 211건 처리시간 0.024초

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

  • 김태구
    • 보존과학연구
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    • 통권31호
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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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소방대원들의 작업자세에 따른 족저압력 분석 (Analysis of Foot Pressure according to the Work Postures on Fire Fighters)

  • 손성민;노효련
    • 한국안전학회지
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    • 제28권1호
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    • pp.88-94
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    • 2013
  • The purpose of this study is to find out the difference of foot pressure according to the firefighter's work postures for providing the basic information to prevent Musculoskeletal disorders. This study was conducted by 9 male firefighters. Work postures were selected for rescuee handling, fire hose and hydraulic rescue equipment work postures. These were divided into 3 position, "High", "Middle" and the postures of taking out and letting down hydraulic rescue equipment were analyzed as starting point and end point respectively. Foot Pressure was used to analyze contact area, peak pressure, and maximum force in terms of work postures, and compared between fire hose and hydraulic rescue equipment work postures. The results of foot pressure are as follows. According to the results of rescuee handling work postures, one person handling posture showed wide contact area and foot pressure showed the highest at right foot. Accoridng to the (High), (Middle), (Low) postures of fire hose, the results didn't show the difference among the contact area, peak pressure and maximum force. As the results of hydraulic rescue equipment work postures, (Low) postures showed the highest in terms of the right foot of contact area, peak pressure and maximum force and (High) postures showed the highest in left foot. The increase of foot pressure lead to be inconvenience of low extremity and muscle fatigue for maintaining postural control cause pain. Thus, it is necessary to design insole-equipped working shoe for reduce the impulse and effect of foot during the rescuee handling work which standing out as foot pressure.

제연구역 출입문 개방 각도에 따른 폐쇄력에 관한 연구 (A Study on the Closing Force according to the Opening Angle of the Door in the Smoke Control System)

  • 오원신;정석환
    • 대한안전경영과학회지
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    • 제23권4호
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    • pp.43-48
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    • 2021
  • In this study, the experiment was conducted on a fire door(W × H = 0.98 m × 2.19 m) installed on the vestibule. The effective leakage area for each opening angles and closing forces derived from the impulse-momentum equation was compared and analyzed with the experimental results. As a result of the experiment, the major factors affecting the door closing forces were the pressure difference and the area of the door. The difference of door closing forces between measured and calculated values by the impulse-momentum equation showed a deviation of less than ±15% at the opening angles of 5°to 10°. At the door opening angle of 2.5°, the dynamic pressure was much higher than the measured static pressure, and this pressure difference is estimated to be air resistance acting to prevent the door from being completely closed.

Assessment of Post-Earthquake Fire Behavior of a Steel MRF Building in a Low Seismic Region

  • Chicchi, Rachel;Varma, Amit
    • 국제강구조저널
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    • 제18권4호
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    • pp.1470-1481
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    • 2018
  • Building-level response to post-earthquake fire hazards in steel buildings has been assessed using primarily two-dimensional analyses of the lateral force resisting system. This approach may not adequately consider potential vulnerabilities in the gravity framing system. For this reason, three-dimensional (3D) finite element models of a 10-story case study building with perimeter moment resisting frames were developed to analyze post-earthquake fire events and better understand building response. Earthquakes are simulated using ground motion time histories, while Eurocode parametric time-temperature curves are used to represent compartment fires. Incremental dynamic analysis and incremental fire analysis procedures capture a range of hazard intensities. Findings show that the structural response due to earthquake and fire hazards are somewhat decoupled from one another. Regardless of the level of plastic hinging present in the moment framing system due to a seismic event, gravity column failure is the initiating failure mode in a fire event.

전단 연결재의 고온 성능 평가에 관한 연구 (A Study on the Slip Test of Shear Connector in Fire)

  • 한상훈;박원섭;이철호
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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    • pp.48-51
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    • 2008
  • Shear connector is the element which resist in the horizontal shear force between steel and concrete of composite members and the stud bolt is often used because of its constructional convenience and serviceability. Although the push-out test is the most common method to evaluate shear slip behaviour, it is suitable for only room temperature conditions. In this study, we investigated about shear force, temperature distribution and slip displacement of shear connector in high temperature through the modified push-out test with electronic furnace invented for steel part heating.

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자유수면의 출렁임이 이동형 소방용수 저장탱크의 수직 벽면에 미치는 동수력에 대한 수치해석 (A Numerical Study on Hydrodynamic Force Affecting the Vertical Wall of a Portable Water Storage Tank)

  • 박진수;소수현;장택수
    • 한국화재소방학회논문지
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    • 제31권3호
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    • pp.49-53
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    • 2017
  • 본 연구에서는 이동형 소방용수 저장탱크 내의 소방용수의 낙하를 단순화하고 이 낙하에 따른 자유수면의 출렁임을 수치 해석하여 수직 벽면에 미치는 동수력을 계산하였다. 소방용수의 낙하에 따른 자유 수면의 출렁임을 수치해석하기 위해 Jang에 의해 개발된 분산관계 보존 방법을 이용하였다. 또한, 다양한 자유 수면의 출렁임을 수치 해석하고자 소방용수의 낙하 높이, 낙하 위치 및 물기둥 폭 조건에 대해 계수 영향 해석을 수행하였다. 따라서 본 연구를 통해 분산관계 보존 방법을 통한 소방용수 저장탱크 내의 자유 수면의 출렁임을 효과적으로 수치 해석할 수 있었고 소방용수 저장탱크의 동수력 영향을 예측하는 데에 적용 가능성을 엿볼 수 있었다.

굴참나무 낙엽의 Fire Whirl 특성에 관한 실험 및 수치해석 연구 (Numerical and Experimental Study on the Fire Whirl Characteristics of Oriental Oak Leaves)

  • 배승용;유홍선;홍기배
    • 한국화재소방학회논문지
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    • 제23권3호
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    • pp.73-78
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    • 2009
  • Fire whirl은 도시 및 산림화재와 같이 광범위한 지형에서 주로 발생하며, 화염주위 환경의 불안전성에 의해 발생하는 현상이다. Fire whirl은 드물게 발생하지만, 높은 흡입력과 양력을 가지게 되어 연소속도를 증가시키는 매우 위험한 현상이다. 본 연구에서는 산림화재에서 발생하는 fire whirl 특성에 대한 고찰을 위해 굴참나무 낙엽을 이용한 fire whirl 실험 및 수치해석 연구를 실시하였다. 실험 결과 유입공기의 속도가 증가함에 따라 화원주위의 회전강도가 증가하여 발열량 및 화염길이가 일반 풀화재에 비해 최대 22.8%, 18.4% 증가하였으며, 수치해석은 실험결과와 유사한 경향을 나타내었다.

볼록한 바닥면 설계를 통한 소방용수 저장탱크의 수직 벽면에서의 동수력 저감 연구 (Reduction of Hydrodynamic Force Acting on the Vertical Wall of a Portable Water Storage Tank by Convex bottom Design)

  • 소수현;박진수;성홍근;장택수
    • 한국화재소방학회논문지
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    • 제32권6호
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    • pp.69-73
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    • 2018
  • 본 연구에서는 볼록한 바닥면을 가진 이동형 소방용수 저장탱크의 수직 벽면에 작용하는 동수력을 계산하고 그 결과를 바탕으로 볼록한 바닥면 설계를 통한 동수력의 감소 효과를 확인하고자 하였다. 수치 모의 실험하기 위해 바닥의 형태를 볼록하게 한 수치 해석 영역을 구성하였으며, 특정 위치와 높이에 용수 공급 노즐을 위치시켜 용수를 낙하시켰다. 용수 낙하에 의한 자유 수면의 출렁임과 수직 벽면에서의 유체 벽 오름을 선형 Peregrine 방정식을 이용하여 수치 모사하고 동수력을 계산하였으며, 그 결과를 오목한 바닥면 및 동일한 해석 조건에서 얻은 동수력과 서로 비교 분석하였다. 결과적으로 오목한 바닥면 설계에 비해 볼록한 바닥면 설계를 통해 수직 벽면에서의 동수력이 더 작아짐을 확인할 수 있었다. 본 연구 결과는 이동형 소방용수 저장탱크의 안정적인 구조 설계 및 운용에 기여할 수 있을 것으로 사료된다.

화재조사제도 개선방안에 관한 연구 (Study on Improvement of Fire Investigation System)

  • 고기봉;이시영
    • 한국화재소방학회논문지
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    • 제23권2호
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    • pp.101-110
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    • 2009
  • 현재 우리나라의 화재조사 제도는 소방, 경찰 등 공적영역 중심으로 이루어지고 있어, 제조물 하자에 따른 화재발생 시 화재피해 이재민들의 권익보호를 위한 '민간 화재조사관 제도'와 같은 사적영역의 화재조사 제도는 매우 취약한 것으로 나타났다. 또한 화재조사 관련 법률이 각 기관별로 분산 적용되고 있기 때문에 유사기관간의 중복조사로 인한 민원발생, 화재조사 현장에서 타 기관을 배제하는 과잉대응, 화재조사 조직 및 인력의 중복운영으로 비효율적인 행정력 낭비 등 많은 문제점이 발생하고 있다. 본 연구논문에서는 우리나라의 화재조사제도에 관한 전반적인 운영 실태와 문제점을 살펴보고 공적영역 및 사적영역에서 화재조사제도 개선방안을 도출하였다.

Study on the fire resistance of castellated composite beams with ortho-hexagonal holes and different beam-end constraints

  • Junli Lyu;Encong Zhu;Rukai Li;Bai Sun;Zili Wang
    • Steel and Composite Structures
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    • 제46권4호
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    • pp.539-551
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    • 2023
  • In order to study the fire resistance of castellated composite beams with ortho-hexagonal holes and different beam-end restraints, temperature rise tests with constant load were conducted on full-scale castellated composite beams with ortho-hexagonal holes and hinge or rigid joint constraints to investigate the temperature distribution, displacement changes and failure patterns of castellated composite beams with two different beam-end constraints during the whole course of fire. The results show that (1) During the fire, the axial pressure and horizontal expansion deformation generated in the rigid joint constrained composite beam were larger than those in the hinge joint constrained castellated composite beam, and their maximum horizontal expansion displacements were 30.2 mm and 17.8 mm, respectively. (2) After the fire, the cracks on the slab surface of the castellated composite beam with rigid joint constraint were more complicated than hinge restraint, and the failure more serious; the lower flange and web at the ends of the castellated steal beams with hinge and rigid joint constraint produced serious local buckling, and the angles of the ortho-hexagonal holes at the support cracked; the welds at both ends of the castellated composite beam with rigid joint constraint cracked. (3) Based on the simplified calculation method of solid-web composite beam, considering the effect of holes on the web, this paper calculated the axial force and displacement of the beam-end constrained castellated composite beams under fire. The calculation results agreed well with the test results.