THE COMPARISON OF TOTAL AND PHASED EVACUATION STRATEGIES FOR A HIGH-RISE OFFICE BUILDING

Abstract

This research work aims to explore the difference between total and phased evacuation strategies in high-rise office buildings and provide guidance on evacuation strategies for decision-makers in determining allowable occupant load.

This work focuses on evaluating the principal factors (building height and occupant load) that may have an impact on egress time and provides a comparison of total versus phased evacuation in a hypothetical high-rise office building through a computer simulation using MassMotion. The comparison is separated into two aspects: total egress time and floor clearing time.

The current thesis determined that the difference of total egress time between these two strategies increases with increased building height. The difference of total egress time between total and phased evacuation is from 165 to 878 seconds with the heights of building from 11 stories to 31 stories, respectively. The floor clearing time for the affected floors is similar in total evacuation strategy in different building heights. Also, in various building heights, the floor clearing time for affected floors has little difference in phased evacuation strategy. Moreover, this thesis depicted a graph of the floor clearing time in these two fire strategies with different occupant load factors. If a phased evacuation strategy is implemented, a decrease in the occupant load factor can be accommodated which results in the same floor clearing time as for a total evacuation strategy. The current thesis generated an equation to estimate the decrease in the occupant load factor between total and phased evacuation based on the same floor clearing time.

There is a limited research work available for the comparison of total and phased evacuation. This research work provides guidance for building planners and engineers in determining total and phased evacuation strategies for high-rise office buildings. For the buildings studied, an equation is provided for engineers to quantify the impact of differences in total and phased evacuations.