Uncertainty analysis on number of fatalities in building fires

A probabilistic ASET (Available Safe Egress Time)/RSET (Required Safe Egress Time) timeline assessment approach is presented to make uncertainty analysis on number of fatalities in building fires. ASET and RSET are achieved as two dependent random variables with consideration of uncertainties of fire dynamics and human behaviors. When analyzing stochastic ASET, uncertainty of design fires is considered by coupling Monte Carlo simulation with two-zone fire model. When analyzing stochastic RSET, uncertainty of fire detection and alarm time is considered by coupling fire model and Monte Carlo simulation. Occupant pre-movement time is proposed as probability distribution. The interdependency between ASET and RSET is considered in the analysis process by lognormal fire growth rates. To demonstrate the approach, a case study is discussed.