Fire risk assessment of multi-story buildings based on fragility analysis

Recent efforts aim at assessing the fire performance of structures in a probabilistic framework. But there is still no well-established method to quantify the reliability of entire buildings. Previous works focused on isolated structural members, therefore not allowing for a determination of the global safety level of buildings. Here, a new methodology is developed to quantify the reliability of buildings in fire. The methodology uses Monte Carlo simulations for constructing fragility functions associated with different fire breakout locations in a building, then combines the functions to characterize the overall building conditional probability of failure, and finally incorporates the probabilistic models for intensity measure and fire occurrence likelihood. The methodology is applied to multi-story steel buildings. This work addresses fire reliability at the building scale, and therefore is useful for standardizing safety level as well as for evaluating community resilience.