A Study on the Layout of Egress Stairs and Evacuation according to Separation Distance of the Stairs in the Library Building's

공공도서관 건물의 직통계단 배치유형과 이격거리에 따른 피난과 기준개선에 관한 연구

Required evacuation time is a very important factor in Performance-based design for egress safety. If the building has large space or numbers of occupants, location of exit stairs on the floor has great influences on egress time. According to the Building Code, two or more stairs need to be installed for buildings over a standard size because the placement of stairs is related to the design of two-way evacuation. In South of Korea, a standard for walking distance to exits is only considered to relate to placement of the exits. This study analyzes a way to place egress stairs and an improvement of evacuation, targeting buildings which comparatively have large floor area. In this study, walking distance and exits separation are considered regarding to placement of escape stairs to reduce evacuation time. First, the cases of public library in Korea are analyzed. The evacuation time change which depends on the distance is observed through evacuation simulation based on the public library drawings. As a result, evacuation time is reduced from a maximum 16% to minimum 4.4% when the exit stairs separation rule is considered. However, when stairs are placed in the middle of the floor, the application of exit separation rules increases egress time to maximum 28%. It will be continued to study on standards in relation to the number of exits and kinds of types of floor plans.