Novel modelling approach for evacuation strategies of tall towers - A case study of Lotus Tower

Rapid urbanisation and population growth have led to the construction of many high-rise and ultra-high-rise buildings globally. Concerns over evacuation of the occupants’ safety in extreme events such as fire or terrorist attacks are increasing. These issues have even restricted the height of tall buildings around the world. Major codes forbid the use of elevators in the event of a fire, unless they are specifically designed as evacuation elevators. However, elevators have known to be the most efficient way for vertical transport. In this work, a new approach of planning for overall emergency occupant egress through evacuation elevators is investigated using a sophisticated numerical modelling technique. The 350 m Lotus Tower, which is under construction in Colombo Sri Lanka, and going to be the tallest tower in South Asia, is taken as a case study to describe the evacuation methodology. The influence of important egress parameters such as the crowd flow density and evacuee demographics are also investigated. The work reported in this paper led to some layout changes in the Lotus Tower.