Research on the rules and strategies of coordinated evacuation of stairways and elevators in high-rise buildings

In high-rise emergencies, relying solely on stairs for evacuation may hinder timely escape. Therefore, elevator-assisted stair evacuation should be considered to improve efficiency. Limited research exists on coordinated stair-elevator evacuation, particularly for upward and downward movements involving refuge floors. A 10-story case study was constructed using MassMotion software, based on the Social Forces Model, to explore the effects of elevator-served floor, building population, and percentage of the population using the elevator on evacuation. Findings were applied to a real building. Results indicate that evacuation time increases with the number of elevator-served floors. Upward stair-elevator coordination outperformed downward evacuation, unaffected by building population. For upward evacuation, deploying elevators on floors 1 or 1–2 reduced evacuation times compared to stairs alone. Downward evacuation achieved time savings using elevators on floors 10 or 9–10. Allocating elevators to 100% of occupants on the lowest or highest floors, or 50% on floors 1–2 for upward, or 9–10 for downward evacuation, minimized evacuation duration. Elevator-assisted evacuation reduced evacuation times by 11.7% for upward evacuation, and 8.4% for downward evacuation, suggesting prioritization of elevators for upward evacuees. This research provides theoretical insights for optimizing the coordination of stairs and elevators in high-rise building evacuations.