An Evacuation Design Method for Deep Underground Buildings Based on Occupants' Safety

: Safe evacuation is one of the key challenges for underground buildings to greater depth expansion. This study proposes a combined upward and downward evacuation method for deep underground buildings. It compared the combined upward and downward evacuation method and the traditional evacuation method through simulation and evacuation experiments. The combined upward and downward evacuation method includes a safety zone, two evacuation direction change points, and a staggered staircase design. Research found that in the combined upward and downward evacuation method, the total evacuation time is shortest when the evacuation direction change points are set at approximately 6:9:5 of the total building depth from top to bottom, with safety zone and staggered staircase designs implemented. Finally, a novel evacuation design method for deep underground buildings is proposed that is based on prioritizing occupants' safety. This study's results offer efficient evacuation solutions and a novel design method for such deep underground buildings.