Adequacy of Safe Egress Design Codes for Supertall Buildings
Edgar C. L. Pang and Wan-Ki Chow
Research Centre for Fire Engineering, Department of Building Services Engineering, The Hong Kong Polytechnic University, Hunghom, Kowloon, Hong Kong, China
Emergency evacuation for supertall buildings with heights over 200 m require a very long time for occupants to travel down the buildings. Occupants might jam into protected lobbies and staircases, extending the waiting time. There is not yet any code requirement specifically for emergency evacuation in supertall buildings, which are criticized for using the same codes for buildings with normal heights. Further, the evacuation design for several existing supertall buildings does not even follow prescriptive fire-safety codes. The underlying problems have not yet been addressed by thorough studies. Evacuation in such tall buildings in Hong Kong will be studied in this paper. The assumptions made in the local prescriptive codes for safe egress will be justified. Three buildings with evacuation design complying with the local codes are considered as examples. A commercial building, a hotel, and a residential block in Hong Kong are taken as examples. The key design parameters in the local codes are for 40 people evacuating with a flow rate of 1.1 person/s through the staircase between typical floors. The evacuation time from each floor to the protected lobby is assumed to be within 5 min. The evacuation times in different scenarios with these assumptions are calculated. Such assumptions do not hold under a high occupant load. The total evacuation time would be extended significantly when the travelling flows of occupants are blocked in any of the evacuation routes. Different fire-safety management schemes with staged evacuation, such as assigning higher priorities to evacuate lower or upper floors first, are evaluated. The results observed for safe egress are then discussed.
-  K. H. Woo, “Final Report of the Inquiry into the Garley Building Fire on 20 November 1996,” Printing Department, Hong Kong, 1997.
-  W. K. Chow, “Evacuation in a Supertall Residential Complex,” J. of Applied Fire Science, 13, pp. 291-300, 2004-2005.
-  P. Olsson, “Hong Kong Highlights,” Fire Prevention and Fire Engineers J., February 2003.
-  E. C. L. Pang, W. K. Chow, and S. S. Han, “Evacuation Strategy for Supertall Buildings,” The First International Conference on Building Energy and Environment (COBEE), 13-16 July 2008, Dalian, China, Vol.1-3, pp. 2094-2100 – Poster presentation, 2008.
-  Fire Services Department, “Codes of Practice for Minimum Fire Service Installations and Equipment and Inspection, Testing and Maintenance of Installation and Equipment,” Hong Kong Special Administrative Region, 2005.
-  Council on Tall Buildings and Urban Habitat, “Tall Buildings in Numbers,” CTBUH Journal – Int. J. on Tall Buildings and Urban Habitat, Issue II, pp. 46-47, 2011.
-  Building Authority, “Code of Practice for the Provision of Means of Escape in Case of Fire,” Hong Kong, 1996.
-  Buildings and Lands Department, “Codes of Practice on Provision on Means of Escape in Case of Fire and Allied Requirements,” Hong Kong, 1986.
-  Public Works Department, “Code of Practice on Provisions on Means of Escape in Case of Fire and Allied Requirements,” Hong Kong, 1959.
-  Public Works Department, “Codes of Practice under the Building Ordinance Wind Effects and Provision on Means of Escape in Case of Fire and Allied Requirements, Version 1 in 1968,” Hong Kong, 1976.
-  W. K. Chow and J. Li, “Evacuation of Atria under Different Uses,” ASCE – J. of Architectural Engineering, Vol.13, No.2, pp. 78-83, 2007.
-  Building Authority, “Code of Practice for Fire Resisting Construction. Building Authority,” Hong Kong, 1996.
-  Buildings Department, “Code of Practice for Means of Access for Fire Fighting and Rescue,” Hong Kong Special Administrative Region, 2004.
-  Buildings Department, “Code of Practice for Fire Safety in Buildings 2011,” Hong Kong Special Administrative Region, September 2011.
-  S. C. Tsui and W. K. Chow, “Review on the Local Code of Practice for the Provision of Means of Escape,” Int. J. on Engineering Performance-Based Fire Codes, Vol.4, No.2, pp. 35-50, 2002.
-  H. E. Nelson and F. W. Mowrer, “Emergency Movement,” SFPE Handbook of Fire Protection Engineering, Third Edition, Section 3, Chapter 14, pp. 3-367-3-380, National Fire Protection Association, USA, 2002.
-  Z. Fang, S. M. Lo, and J. A. Lu, “On the Relationship between Crowd Density andMovement Velocity,” Fire Safety J., 38, pp. 271-283, 2003.
-  Buildings Department, “Guide to Fire Engineering Approach, Practice Note for Authorized Persons and Registered Structural Engineers 204,” Hong Kong Special Administrative Region, 1998.
-  J. Pauls, “Calculating Evacuation Times for Tall Buildings,” Fire Safety J., 12, pp. 213-236, 1987.
-  W. K. Chow, and C. M. Y. Ng, “Waiting Time in Emergency Evacuation of Crowded Public Transport Terminals,” Safety Science, Vol.46, No.5, pp. 844-857, 2008.
-  J. Li and W. K. Chow, “Review on Emergency Evacuation Time Estimation for Performance-Based Fire Safety Design,” J. of Applied Fire Science, Vol.15, No.2, pp. 147-163, 2006.
-  J. Li and W. K. Chow, “Key Equations for Studying Emergency Evacuation in Performance-Based Design,” 3rd International Symposium on The 21st Century Center of Excellence Program: Tokyo University of Science, 10-11 March 2008, Tokyo, Japan, 2008.
-  W. K. Chow, “Six Points to Note in Applying Timeline Analysis in Performance-Based Design for Fire Safety Provisions in the Far East,” Int. J. on Engineering Performance-Based Fire Codes, Vol.10, No.1, pp. 1-5, 2011.
-  CM. Y. Ng and W. K. Chow, “A Brief Review on the Time Line Concept in Evacuation,” Int. J. on Architectural Science, Vol.7, No.1, pp. 1-13, 2006.
-  E.M. Cepolina, “Phased Evacuation: an Optimisation Model which Takes into Account the Capacity Drop Phenomenon in Pedestrian Flows,” Fire Safety J., 44, pp. 532-544, 2009.
-  S. Gwynne, M. Owen, E. R. Galea, L. Filippidis, and P. J. Lawrence, “Adaptive Decision-Making in Response to Crowd Formations in BuildingEXODUS,” J. of Applied Fire Science, Vol.8, No.4, pp. 301-325, 1998.
-  M. Owen, E. R. Galea, and P. J. Lawrence, “The EXODUS Evacuation Model Applied to Building Evacuation Scenarios,” J. of Fire Protection Engineering, Vol.8, No.2, pp. 65-85, 1996.
-  C. L. Chow andW. K. Chow, “Fire Safety Aspects of Refuge Floors in Supertall Building with Computational Fluid Dynamics,” J. of Civil Engineering and Management, Vol.15, No.3, pp. 225-236, 2009.
-  South China Morning Post, “Lan Kwai Fong Tragedy,” Hong Kong, 2 January 1993.
-  Apple Daily, “Mei Foo Sun Chuen Fire,” Hong Kong, 9 April 1997.
-  R. P. Schifiliti, B. J. Meacham, and R. L. P. Custer, “Design of Detection Systems,” SFPE Handbook of Fire Protection Engineering, Third Edition, Section 4, Chapter 1, pp. 4-1-4-43, National Fire Protection Association, USA, 2002.
-  The Standard, “One Fireman Killed, 6 Hurt in Firestorm,” Hong Kong, 23 May 2007.
-  The Standard, “Inferno Heroes Mourned,” Hong Kong, 11 August 2008.
-  The Standard, “Fire Veteran Dies and 3 Hurt in Factory Hell,” Hong Kong, 9 March 2010.
-  J. G. Quintiere, “Opportunities to Learn from 9/11,” Fire Protection Engineering, 21, Winter, pp. 38-42, 2004.
-  W. K. Chow (Ed.), Proc. of the Fire Conference 2004 – Total Fire Safety Concept, 6-7, December 2004, Hong Kong, China, Vol.1, pp. 94-99, 2004.
This article is published under a Creative Commons Attribution-NoDerivatives 4.0 International License.