- Author
-
Williams, J.
- Title
- Life Safety Risk Assessment for Firecells With a Single Means of Escape.
- Coporate
- University of Canterbury, Christchurch, New Zealand
- Report
-
Fire Engineering Research Report 03/3,
June 2003,
315 p.
- Distribution
- FOR MORE INFORMATION CONTACT: School of Engineering, University of Canterbury, Private Bag 4800, Christchurch, New Zealand. Telephone: 643-364-2250, Fax: 643-364-2758
- Keywords
-
life safety
|
risk assessment
|
escape means
|
egress
|
evacuation
|
codes
|
firecells
|
risk analysis
|
fire departments
|
building codes
|
time
|
regulations
|
NFPA 101
|
smoke layers
|
heat detectors
|
sprinklers
|
evacuation time
|
fire statistics
|
fire suppression
- Identifiers
- egress via single escape routes: code requirements; escape from the firecell of fire origin; risk assessment of escape from firecell of fire origin; risk analysis of alternative solutions; analysis of fire service statistics; fire related clauses in the New Zealand building code; verification of spreadsheed with FPETool; graphical results from T2 fire analyses; graphical results from item fire analyses
- Abstract
- The Acceptable Solutions ClASt to the New Zealand Building Code impose a limit of 50 people that may be served by a single escape route. Restrictions are also placed on the travel distance between the most distant occupied space and the distance to reach the nearest safe path, safe place, or another fuecell. These restrictions are related to the nature of the occupancy of the firecell, and the detection systems installed. This report compares the requirements of the New Zealand Acceptable Solutions with other equivalent documents from the United Kingdom and the United States of America, and assess the escape times associated with the requirements. It then reviews the detection, pre-movement, tenability, and available escape times from various standard t2 and item fires in a variety of flfecell sizes, for a variety of occupancies, and quantifies the probability of successful egress from an open plan firecell with a single means of escape. It is shown that if an adequate egress width is provided, the number of occupants in the room need not influence the time required to egress, but that the minimum door widths required by most approved documents will result in some queuing. Therefore, the limit of 50 people does not appear to result from a fire safety consideration, provided adequate egress widths are provided. It is concluded that the risk of obstruction by the fire is generally small, with the most likely cause of failure being from loss of tenability in the flfecell. The greatest chance of successful egress is from a large flfecell, there being few successful outcomes from small firecells. The provision of sprinklers has little effect on the tenability time in the fIrecell. There is some improvement in larger fIrecells, but not in those with smaller floor areas. The main benefit is in the control of the fire size, reducing the radiation levels and hence the risk of the fIre obstructing the egress route.