Study on Pedestrian Dynamics in Stairwell Based on Circle-Based Floor Field

Due to constraint land, more and more high-rise buildings are built in cities. It is unsafe to evacuate by elevators, thus stairs has an important impact on evacuation. So it is of great significance to analyze evacuation in stairwell. However, few researchers could reproduce occupant arc trajectories at the mid-landing in stairwell. A stair model based on circle-based floor field (Stair Circle-based Optimal Step Model — SCOSM) is proposed to investigate human performance in stairwell, in which occupants could make a turn with a certain point and move like as an arc. SCOSM is testified to validate by comparing simulated results and experimental datasets in respect of whole evacuation time and net person for each floor. What is more, the model is used to study the effect of interface. It is found when width of stairs (S1) is equal to the width of mid-landing (S2), pedestrian flow is dominated by the width of mid-landing (S2). As for effect of stair geometry on merging, structures except scenario a are inclined to preferring occupants from floor. The studies in this paper could help offer engineers a technical foundation for codes and fire protection design.