Emergency evacuation in high-rise apartment building is a challenge for fire safety professionals. Lift evacuation is a controversial issue because the safe operation of lift is not ensured under the existing design and operating conditions. Lifts are not permitted for public evacuation in apartment buildings during fire emergencies as per the provisions of building codes and regulations. However, the concept of using lifts for emergency evacuation has been gaining considerable attention during recent years. The lift evacuation can be considered as an alternative facility if it is efficient, reliable and readily accessible. It can also provide a safer means of evacuation for the aged and disabled persons, who may not be able to evacuate promptly, efficiently and unassisted using the exit stairs during fire emergencies. Moreover, lifts can enable building corporate management to easily and promptly access the fireaffected floor and commence fire fighting. The work on the use of lifts for emergency evacuation was initiated in the early 1990s at the National Institute of Standards and Technology (NIST, USA) in which pros and cons were analysed in order to develop suitable guidelines. This research project examines the feasibility of using lifts along with design modifications as an alternative facility for a safer and more efficient emergency evacuation. The scope of this research is limited to apartment buildings where occupant load is low and fire load is generally confined to dwelling compartment units. This research project analysed the important issues in relation to the use of lifts for emergency evacuation. The issues were divided into three categories: human behavioural response, fire hazards and lift operational mechanism. Output variables relating to human behavioural response were modelled and analysed as a stochastic process. Residents’ choice for using evacuation routes was determined using a survey. The issues of fire hazards (fire, smoke and toxic gases) were analysed for occupant safety under variable conditions using the concept of fire safety index. The issues of lift operational mechanism such as lift malfunctioning due to excessive temperature, electric power failure and water damage were considered for developing probabilistic models. An integrated approach of risk assessment for the issues of human behavioural response and fire hazards (such as ‘decision uncertainty’, ‘panic’, ‘nonfatal and fatal injuries’) was developed based on the Multi-Objectives Decision Analysis method. The results for lift and stair systems were compared and the feasibility of using lift with design modifications was analysed for alternative designs and evacuation strategies. The outcomes of this research have shown that using lifts with a protected lobby for up to one-fourth of the building population (who may be aged and disabled) has huge potential as an alternative evacuation facility with enhanced level of safety. Lifts with protected lobby for one-fourth of the building population showed an improved level of fire safety from exposure to fire effluents. The reliability of lift operational mechanism is also improved in protected lift shafts. Lifts with protected lobby for up to one-fourth of the building population and stairs for up to three-fourth of the building population showed an improved evacuation safety. The risks in combined evacuation systems (protected lifts and stairs) are found to be lower when compared to using stairs or protected lifts. Lifts with double lobby protection (for example, two levels of compartmentation with fire and smoke doors for lift lobby) showed further improvements. This research has proposed alternative designs for lifts and developed models for analyzing evacuation effectiveness based on risks related to human behaviour, fire hazards and operational mechanism. It has shown that a combined use of lifts and stairs has significant advantages. The performance based lift evacuation system is achievable in apartment buildings. These research findings are based on uncertainty analysis, which can be further extended to other types of buildings in the future.
| Identifer | oai:union.ndltd.org:ADTP/265778 |
| Date | January 2008 |
| Creators | Sharma, Than Singh |
| Publisher | Queensland University of Technology |
| Source Sets | Australiasian Digital Theses Program |
| Detected Language | English |
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