2018 KEPIC-Week, Busan ~31 화재사건과기술기준 - 건물화재에대한공학적분석 - Dr. Ing. Wee Kyong KIM

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1 2018 KEPIC-Week, Busan ~31 화재사건과기술기준 - 건물화재에대한공학적분석 - Dr. Ing. Wee Kyong KIM

2 Introduction and Fire Dynamics Ignition and Prevention Factors Fire Growth / Flame Spread Fire Suppression, Detection and Alarm Fire Confinement / Structural Integrity Smoke Movement / Management Egress Systems and Tenability Analysis

3 1. Introduction Definitions of failure Failure is an unacceptable difference between expected and observed performance ASCE Technical Committee on Forensics Distortion, breakage, deterioration or other fault in an item, component, system, assembly or structure that results in unsatisfactory performance of the function for which it was designed NFPA 921, Guide for Fire and Explosion Investigations Definition of fire investigation The process of determining the origin, cause, and development of a fire or explosion

4 1. Introduction Classifications of failure Design Installation Inspection, testing and maintenance Equipment malfunction Training / operation / administrative controls Communication

5 1. Introduction Origin and Cause issues Most of the focus in fire investigation is on the cause of ignition What started the fire? Potential cause of action against responsible parties Was the fire intentionally set (arson)? Criminal prosecution Denial of insurance coverage

6 1. Introduction Engineering issues What physical / chemical / operational factors permit a fire or explosion? What factors permit a small fire to grow large and cause unacceptable damage or injury? Flammability of materials Fire detection and alarm notification Fire suppression Smoke management / control Fire confinement / structural integrity Means of egress

7 1. Introduction Role of Codes and Standards Fire codes and many fire safety standard : Prevention Fire test/fp system installation standards : Mitigation Building codes : Describe fire safety systems and features that should be in place to mitigate the consequences Reference Fire test/fp system installation standards to assure compliance with the code s performance objectives Building codes, Fire codes and many fire safety standard Are used to evaluate whether an appropriate standard of care has been applied in design, installation, operation and maintenance of building and fire protection systems

8 1. Introduction Reasons for post-fire analyses Identify criminal activity, Assess responsibilities Provide feedback for improvements to manufactures, designers and regulators Reduce risk (insurance) Identify trends (data) Learn from past mistake to prevent reoccurrences in the future Determine Origin and Cause and provide feedback to Protect property(reduce damages), Save lives and prevent injuries, conduct research to improve codes, standards, regulation, Reduce impact on environment, protect firefighters

9 2. Fire Dynamics Stages and elements of enclosure fires Fire plume/ceiling jet, Enclosure smoke filling, Pre-flashover Post-flashover Data needs for fire scenario reconstruction, Fire patterns and their analysis, Fire Modeling tools, uses and limitations

10 2. Fire Dynamics Case study : MGM Grand Hotel Fire ( ) 세번째로큰호텔화재 : 85 명사망, 650 명부상 화재원인 : The Deli Restaurant( 소켓의접지불량 ) 문제점 : 상주지역 (SP 면제 : 화재시비상주지역 ), 가연성물질, 수직관통부, 연기확산 (HVAC), 비상구잠금 Fire reconstruction is based heavily on issues addressed by FPEs Large scale fire testing supported has been used.( 화재전파속도 : 4.6~5.8 m/s) Response of materials to fire, Fire pattern analysis, Fire dynamics / modeling

11 3. Ignition and Prevention Factors Introductory concepts : 점화원과가연물 Fire Origin and cause considerations + propagation Ignition sources and their control (Che/Mech/Elec) NFPA 1, 51B, 54, 58, 70, 86, 211 Materials first ignited : 물질상태 ( 기액고 ) 및형상 ( 고 ) Thin solids : t ig = T ig T o q " net/ρcδ Thick solids : t ig = π kρc T ig T o 4 q " net Ignition factors : 설계, 설치, 행정통제, 검사및기기오동작 2

12 3. Ignition and Prevention Factors Case study : The Station nightclub fire ( ) 100 명사망, 250 명부상, 화재원인 : 불꽃이벽마감재에점화 PU foam as interior finish : Life Safety Code Use of pyrotechnics without proper permits/training : 행정통제 Overcrowding / exit capacity / arrangement Lack of early suppression Summary 최초점화된가연물을점화시키기위한점화원능력 최초점화된가연물의점화용이성 최초점화된가연물에노출되는점화원인자 : 설계 / 시공 / 행정

13 4. Fire Growth / Flame Spread Introductory concepts : 화재예방실패다음단계는성장속도제한 Interior finishing ( 조기화재성장 ), floor (Flashover), Furnishing and decorations ( 점화용이 / 조기화재성장 )

14 4. Fire Growth / Flame Spread Material flammability properties / regulation Ignition properties : Effective Thermal properties(thin, thick), Ignition temperature, Heat release rate properties( 연소열, 증발열 ) Performance expectations for flammability Case study : North Central High School 적재된체육관매트에서발화 급속성장 구조적손상 Flammability Characteristics of gym mat and Bleachers( 관중석 ) NFPA 101 : HRR < 100 kw matt 평균 HRR 50 MW

15 5. Fire Detection and Alarm Introductory concepts : Performance expectations for fire detection systems Performance expectations for fire Alarm and communication systems Case study : Signature Foods plant (1998 년 1 월 2 일 ) : 냉동창고, 열감지기 (57 ) dry-pipe/preaction SP, 야간고온수청소작업으로회로차단 ( 고질적인문제 ) 설계, 시공, ITM, 오동작등다양한형태로감지및경보계통손상 화재경보기록은 fire reconstruction 에매우유용한자료 (R type)

16 6. Fire Suppression Performance expectations for fire suppression systems 진압 / 제어 + 감지 / 경보 Factors associated to system failures Case study : River Cities Business Park ( ) SP system 손상 : 적재물배열, 20 만 gal 물탱크전복, 기타원인? Commercial Cooking Fire 설계 / 시공 / 유지관리미흡, 소화약제탱크미동작 ( 안전플러그 ) Refuse Recycling Facility Over 200 sprinklers opened???

17 7. Smoke Movement and Management Introductory concepts Stack effect, Wind effects, Fire-induced buoyancy and expansion, Mechanical ventilation Performance expectations for smoke management systems Case study : Cook County Administration Building( ) 6 명사망, 21 명부상, Open door to store room( 화재지역 ) / Locked doors in stairways / Smoke in occupied stair FDS, CONTAMW Simulations, NIST 사건조사참여 : NIST BFRL website SP-1021 참조 But for deaths of 6 civilian in stairway, CCAB fire may have been considered a fire protection success despite lack of SP protection

18 8. Fire Confinement / Structural Integrity Introductory concepts : Building Type I ~ V 3-hr ratings means no failure 3 hours of real fire exposure Performance expectations for fire barrier Performance expectations for structural elements Test standards : assemblies, doors, windows fire stops Case study : First Interstate Bank(88) / One Meridian Plaza(91) / WTC(01) 공통점 : office furnishings, open floor plans, fire spread to multiple floors 차이점 : FIB( 재사용 ), OMP( 재사용불가 ), WTC( 붕괴 ) Fire resistance of steel-framed structure : Temperature, long-span floor( 열팽창크기 ), 중력방향으로견디는연결부 Pressure Reducing valve 문제점

19 9. Egress Systems / Tenability Analysis Introductory concepts : ASET > RSET Egress system issues : 재실자대비출구크기및수량, 이동거리, 문, 계단 / 복도. Tenability analysis issues Case study : MGM Grand fire