A risk-based equivalence approach to fire resistance design for buildings

This article presents a risk, or probability-based method for determining the residual fire resistance that is required when sprinklers are installed supplementary to building regulatory requirements. The concept of equivalence of a building design to a code-complying design on the basis of risk is introduced. The probability of failure is formulated, taking into account the probability density distributions for fire resistance of building structures and for fire severity. The sprinkler system is treated as a dual-exclusive-status system which has a bi-valued probability distribution. The probability density distribution for fire severity is moderated by the discrete reliability for sprinklers. A parametric study is conducted to demonstrate the sensitivity of the residual fire resistance to sprinkler reliability and fire severity distribution.