建築火災安全のシステム分析 : 第 1 報 物的被害軽減システムの分析

Abstract

Using the data of 3925 building fires occurred in Tokyo during 1981, a building firesafety system has been analysed. The material damage mitigation system whose function is to end a fire to be a slight one and is consited of two parallel subsystems which are initial fire extinguishing system and spontaneous fire extinguishment system has been analysed. The function of the initial fire extinguishing system is to put out a fire in its early stage by active measures such as fire-fighting with water or fire extinguishers and that of the spontaneous fire extinguisment system is to make a fire burnt itself out by passive measures such as making buildings and their contents noncombustible. Success rate of the above three systems have been computed by the difference of building structures and by the difference of fire prevention equipments installed to buildings. Among the 3925 buildings that caused fires, average success rate of the material mitigation system is .754 and that of the initial fire extinguishing system is .617 and that of the spontaneous fire extinguishment system is .358. Major causes of failure of the initial fire extinguishing system have been enumarated and examined using Fault Tree Analysis Method and 45% of the failures were originated from the delay of fire detection by people. Most of the fire spreadings within the fire-proof buildings, which were the result of failure of the spontaneous fire extinguishment system, were through opend or combustible doors and stairwells.