Quantifying fire resilience of buildings considering the impact of water damage accompanied by fire extinguishment

The primary factor that affects the functionality of buildings due to fire is the deterioration caused by heating from hot flames and smoke. The application of water, whether by occupants, firefighters or sprinkler systems, takes an important role in reducing the intensity of the fire. However, it can lead to the impairment of nonstructural components, equipment systems and stored items inside the building rendering them unusable and disrupting the building's functionality for an extended period. Past studies on fire resilience have mainly focused on assessing burn losses in buildings, neglecting the consideration of water losses. This study introduces a new approach that enables a reasonable evaluation of fire resilience of buildings by accounting for the water loss accompanied by fire extinguishment. The new approach is based on the physical prediction of water spread inside the building, which involves calculation of the changes in water levels in each room over time due to transfers between rooms through openings, staircases and gaps, and absorption by room boundary members. The estimated area of water damage is then correlated statistically with the time required for functional recovery, which allows for the assessment of fire resilience. To illustrate the proposed method, we conducted a case study on a four-story office building. When the fire originated on the fourth floor, water applied to the building spread through the corridors and staircases, with the extent of water damage decreasing on the lower floors. Additionally, we employed a Monte Carlo simulation with randomly assigned fire origins to quantitatively evaluate the impact of sprinkler systems on fire resilience. Comparing burn and water losses, we found that burn losses generally exceeded water losses in many cases. However, under specific fire and water application conditions, opposite results were observed, underscoring the importance of assessing both burn and water losses simultaneously for a comprehensive evaluation of fire resilience.