A Multi-Grid Evacuation Model Considering the Threat of Fire to Human Life and its Application to Building Fire Risk Assessment

In the present study, a modified multi-grid fire evacuation model (MG-Fire-Evac) was devised to study the influence of fire-related phenomena such as toxic smoke and heat on occupant evacuating from a burning building. The degree of injury suffered by the occupants is quantified in terms of “health points” (HPs) in the model. When a person’s HP is less than 0.5 or 0.8, he or she is regarded as having succumbed to the fire (becoming a fatality or serious injury). A parameter is defined to represent the degree of influence of the fire on the occupants’ movement, which is used to predict which of three possible kinds of egress is attempted. To decrease the degree of error in the data transferred between the fire simulation and egress model, a finer grid resolution is adopted in the new model. For the scenario examined, simulation results demonstrate that a higher fire load, longer pre-movement time, or narrower exit would all lead to more serious occupant injury in the event of a fire. Based on the MG-Fire-Evac model, a new building fire risk procedure is presented whereby it is possible to predict the death toll and number of serious injuries and to quantitatively evaluate evacuation plans. Compared to the conventional method, the new method is stricter and more scientific. The model and method presented herein will be useful for application to the performance-based design, assessment, and management of building fire safety.