Life safety in single-story steel frame buildings, Part I - deterministic design

This paper discusses fire safety design of single story-, single compartment buildings and evaluates whether time to structural damage is a relevant criterion when lethal fire conditions develop long before any structural fire damage can occur. Current performance-based design practice aims at achieving the life safety objective by preventing structural failure for the entire duration of a natural fire or for a fixed time of standard fire exposure. Prevention of structural fire damage is always relevant for multistory buildings, or buildings with complex geometries as structural fire damage may then threaten occupants and/or firefighters outside the area directly affected by the fire. However, for single-story-, single-compartment buildings, prevention of structural fire damage is less relevant in relation to the life safety objective. The advantage of the new design philosophy presented in this paper is the possibility to define how the level of structural fire resistance in single-story-, single-compartment buildings can be determined in a consistent way. This level of fire resistance requirement in these buildings differ amongst countries but could be harmonized by accepting of the design philosophy suggested in this paper. The proposed approach is demonstrated in a design case study of a steel truss in a typical Swedish single-story steel frame building. While not complying with deemed to satisfy fire resistance ratings, it is argued that the proposed design still can fulfill the life safety objective.Validerad;2019;Nivå 2;2019-12-03 (johcin)