Experimental and numerical evacuation study in tall office building

Abstract

The duration of the evacuation process in case of emergencies in tall buildings is a crucial issue. Various factors have significant impact on the evacuation time, e.g. stairwell geometry, speed, density, pre-evacuation delay, number of occupants and their familiarity with the building, behavior, age, gender, physical abilities, relationships between people, etc. Although there are many studies on the subject, research results from Bulgaria and comparison with those from other places in the world are not yet available. Also, studies performed by researchers who have professional operational firefighting experience are very limited. In this study, two evacuation experiments in a new 107 m tall office building in Bulgaria were designed under the supervision of professional firefighting personnel. The first experiment was conducted to estimate the free movement characteristics under “normal” conditions for determining the average duration of the evacuation and the range of the vertical speed. Thirteen participants were instructed to move down from 17F to outside the building, following their normal habits. Their evacuation times differed in the range from 192 s–328 s, while the vertical speed is highest at the upper floors 0.35 m/s and reduce to 0.20 m/s just before the exits. The second experiment was an evacuation drill of 177 people from the floors they work in the building. The evacuation duration of this experiment for all these people from the building was in the range of 2–6 min. The study is also enriched through Pathfinder software simulations for verification of the results, where a good match was observed (6:26 min total evacuation time). Another simulation at the maximum occupants’ capacity of the building with 2195 people was also run (24:48 min for the total evacuation time). We believe that the benefits achieved on the differences in the real experimental data from different parts of the world can be valuable for validation of tall building evacuation models. In addition, the link between the evacuation drill findings and the professional firefighting considerations, problems and decision-making operations in case of fire is discussed.