As the population has continue to be concentrated with rising land prices and rapid development of vertical transportation technology, more and more buildings are skyscraping. Furthermore, the ultra high-rise buildings are expected to be built more in...
As the population has continue to be concentrated with rising land prices and rapid development of vertical transportation technology, more and more buildings are skyscraping. Furthermore, the ultra high-rise buildings are expected to be built more in order to activate the downtowns through efficient, economic and complex uses of the land as well as position them as city landmarks or symbols.However, ultra high-rise buildings are more vulnerable to disasters than ordinary buildings because they stand highest and widest. In particular a fire at the high altitude may result in a horrible disaster. The stack effect which was little recognized in the past when there were few ultra high-rise buildings is now being spotlighted as the most serious problem in the ultra high-rise buildings fire, since the smoke spread by the stack effect would be the primary source threatening the human life.Smoke control damper and fire protection door are important facilities designed to check and dilute the smoke spread by the stack effect in a skyscraper fire and thereby, help people escape from or fight fire smoothly. According to the result of a survey conducted by National Emergency Management Agency for operation of the smoke control facilities in 2006, about 33% of them were found in poor state. It was further confirmed that most of the fire protection doors leading to the escape stairway from fire were opened arbitrarily by residents, which means that the smoke control damper could not play their own roles. Such findings suggest that poor operation of the smoke control facilities would result in a terrible disaster in case a fire breaks out.The purpose of this study was to simulate the stack effect in a ultra high-rise building fire and thereby, analyze route, speed, pressure and concentration/distribution of the smoke spread by the stack effect and assess the influence of vestibule, smoke control damper and fire protection door over the smoke spread by the stack effect.For this purpose, the researcher reviewed relevant literature and mass media coverages, interviewed with relevant people, and thereupon, simulated a fire in an ultra high-rise building by using a CDF Interpretation program (STAR-CD). The scope of this study was set as follows;(1) Various theoretical aspects of the stack effects in a fire including its smoke-spreading effect(2) Problems of the ultra high-rise buildings in case of a fire(3) Smoke control facilities for ultra high-rise buildings(4) A fire simulation in consideration of the stack effectThe results of this study can be summarized as follows;As a result of simulating a fire in a skyscraper in consideration of the stack effects, it was found that the smoke generated from a fire in a lower part of the skyscraper would be induced by the stack effect into the elevator passage to be pushed up by buoyancy to infiltrate through the elevator door chasms into the smoke control areas (corridors). The results of assessing the influence of smoke damper in the vestibule of elevator and fire protection door over the smoke spread by the stack effect can be summed up as follows;(1) In case the smoke control damper does not work or its air supply volume is small or in case it works normally but the fire protection door is open, the smoke controlled areas would be filled with the smoke spread by the stack effect. After all, the smoke control damper would not play its own role of controlling and diluting the smoke for people''s smooth escape from fire or their effective fire fighting activities.(2) If the smoke control damper works normally with the fire protection door closed, the indoor air would be pressured by the air supply from the smoke control damper to be as high as 40~50Pa, and thus, the smoke spread by the stack effect would be controlled and diluted to help people escape from the fire or fight its smoothly. In such a case, the smoke control damper plays its original role of keeping the smoke off the smoke control areas on the same floor and additionally, plays the role of keeping the smoke spread by the stack effect from rising upwards.