Predicting the Fire Performance of Buildings: Establishing Appropriate Calculation Methods for Regulatory Applications.
Predicting the Fire Performance of Buildings:
Establishing Appropriate Calculation Methods for
Regulatory Applications.
(842 K)
Bukowski, R. W.
Interscience Communications Limited. ASIAFLAM '95.
International Conference on Fire Science and
Engineering, 1st. Proceedings. March 15-16, 1995,
Kowloon, Hong Kong, 9-18 pp, 1995.
Keywords:
fire science; fire protection engineering; fire models;
evacuation; fire codes; performance evaluation;
regulations; safety factors; acceptance criteria;
alternative design; code equivalency; measurement
uncertainties; performance based codes
Abstract:
A recently organized effort in the International Council
for Building Research, Working Commission 14 (CIB W14),
on Engineering Evaluation of Building Fire Safety is
examining the various quantitative methods being
developed to underpin performance-based codes or for
determining equivalency with the implied performance of
existing prescriptive codes. These methods share many
common features and all recognize the range of fire
models and calculational methods that the fire safety
engineering profession have begun to embrace as their
technical foundation. The broad range of assumptions
inherent in the available methods as well as the data
required to utilize them raises some interesting
questions about their appropriateness in applications to
code-regulated situations. Many fire-related
computations have inherent uncertainty because of lack
of understanding of the physics. Thus, one can ask,
where a code defines a minimum level of performance, how
far must the fire safety engineer go to minimize
uncertainty in a calculation intended to verify
compliance? The variability of fire means that there
are no unique answers against which to define accuracy;
and fire experiments involve measurement uncertainties
as well as approximations used to reduce the data which
often have similar form to the calculations we wish to
verify. These methods all focus on managing fire risk,
and their successful application depends on assessing
the acceptable level of risk implied by the current
codes. Some argue that the lack of a public outcry over
fire losses is not a tacit acceptance of those losses by
society. Thus, how can acceptable levels of risk be
determined when regulatory authorities and legislators
are uncomfortable with the notion that there is no zero
risk so some fatalities are inevitable? This paper
explores these questions from the perspective of the
fire scientist, the practicing engineer, and the
regulatory offical. The fire scientist needs to be
explicit about the impact of assumptions on the
applicability of the results. The engineer needs to
utilize methods and assumptions which are justified by
the application and to assess the sensitivity and
uncertainty implications. The regulatory officials are
insisting on appropriate and properly documented
methods. These is a need for models and calculations
incorporated into codes of practice, handbooks, or the
codes themselves to be reviewed, verified, documented,
and approved for use in specific manners and by
qualified persons. There are international efforts to
define levels of risk acceptable to society in specific
occupancies. Until these points are addressed, the
transition to performance-based codes cannot be made
with confidence.
