Publisher’s version / Version de l'éditeur:
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la
première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.
Questions? Contact the NRC Publications Archive team at
PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.
https://publications-cnrc.canada.ca/fra/droits
L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.
Internal Report (National Research Council of Canada. Division of Building
Research), 1977-04
READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.
https://nrc-publications.canada.ca/eng/copyright
NRC Publications Archive Record / Notice des Archives des publications du CNRC :
https://nrc-publications.canada.ca/eng/view/object/?id=d76ff8bb-e113-4580-b330-74b01533372a https://publications-cnrc.canada.ca/fra/voir/objet/?id=d76ff8bb-e113-4580-b330-74b01533372a
NRC Publications Archive
Archives des publications du CNRC
For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.
https://doi.org/10.4224/20359139
Access and use of this website and the material on it are subject to the Terms and Conditions set forth at
Toward a fire protection planning approach II: some considerations in
implementing the life safety design assessment procedure
PREFACE
Systematic approaches to the fire protection planning of buildings are not new. Dissatisfactions with aspects of the customary building code approach have led to the proposal at various times of a number of philosophic approaches intended to complement or supplant traditional procedures, but these have scldom addres3ed themselves intimately to the building designer and the design process.
The life safety design assessment procedure discussed here was conceived as a practical working tool that would be simple
for designers to use and as an aid to common sense and plain thinking in designing for fire safety. The initial steps taken to develop that tool are described. Although certain weaknesses preclude further development of the approach in its present form, a possible way around this difficulty is thought to lie in the concept of a fundamental set of "attributes" that underlie, and characterize the effectiveness of, the techniques utilized by fire protection designers.
Ottawa April 1977
C
.
B.
Crawford Director, DBR/NRCMA'TIONAL RESEARCH CUUNCIL OF CANADA DIVISICIN OF BUILIIING RESEARCH
DBR INTERNAL REPORT NO. 435
TOWARD A FIRE PROTECTION PLANNING APPROACH
-
I I
.
SOME CONS1 DERATIONS IN IMPLEMENTING THELIFE SAFETY DESIGN ASSESSMENT PROCEDURE
by Alan b l . P h i l l i p s
Checked by: G
.
w
.
S.
Approved by: L.
W.
G.
Date: A p r i l 1977Prepared for: 1 i m i t e d d i s t r i b u t i o n
During development o f t h e p h i l o s o p h i c f o u n d a t i o n d i s c u s s e d by
Q u i r o u e t t e ,
'
t h o u g h t was a l s o g i v e n t o how t h e a p p r o a c h , a s t h e nc o n c e i v e d , might b e developed i n t o a p r a c t i c a l working t o o l . The
philosophy i t s e l f was s u b s e q u e n t l y f u r t h e r developed and m o d i f i e d ,
s o t h c r e i s no l o n g e r a n e x a c t c o r r e s p o n d e n c e between t h e c u r r e n t
v c r s i o n s o f t h e working and p h i l o s o p h i c a p p r o a c h e s . T h i s r e p o r t
i s i n t e n d e d simply a s a r e c o r d o f t h o u g h t s d e v e l o p e d and work done on t h e working approach.
The working a p p r o a c h , which w i l l b e termed t h e l i f e s a f e t y
d e s i g n a s s e s s m e n t p r o c e d u r e , was i n t e n d e d t o b e s i m p l e i n u s e , a n a i d t o common s e n s e and p l a i n t h i n k i n g a b o u t d e s i g n i n g f o r f i r e
s a f e t y . C e r t a i n weaknesses p r e c l u d e f u r t h e r development o f t h e
approach i n i t s p r e s e n t form, b u t t h e r e i s a p o s s i b l e way around
t h i s d i f f i c u l t y .
DESCRIPTION O F THE PROCEDURE
The h e a r t o f t h e p r o c e d u r e i s a t a b l e d e r i v e d from one
t o o l s o f f i r e p r o t e c t i o n p r a c t i c e a r e l i s t e d i n a column a t t h e l e f t o f t h e t a b l e , e x p r e s s e d i n forms t h a t make them a s b a s i c a n d i n d e p e n d e n t o f
e a c h o t h e r a s p o s s i b l e . The l i s t i s open t o improvement. These b a s i c
c o n c e p t s w i l l b e r e f e r r e d t o a s p r i n c i p l e s . Any r e a l i s t i c b u i l d i n g f i r e
s a f e t y d e s i g n must n e c e s s a r i l y combine s e v e r a l o f t h e p r i n c i p l e s . Such
a w o r k a b l e c o m b i n a t i o n w i l l b e r e f e r r e d t o a s a s y s t e m . T h i s i s t h e o n l y u s a g e o f t h e word t h a t w i l l b e employed i n t h i s r e p o r t . T h i s o r i g i n a l t a b l e , i d e n t i f i e d a s "Form B", was i n t e n d e d t o b e u s e d f o r l i f e s a f e t y a s s e s s m e n t . O t h e r v e r s i o n s o f t h e form were t o have b e e n used f o r a s s e s s i n g p r o t e c t i o n o f o t h e r v a l u e s , e . g.
,
p r o p e r t y . The v a r i o u s t y p e s o f h a z a r d s , which i n t h e l i f e s a f e t y c o n t e x t a r e F i r e and Smoke, were c o n s i d e r e d s e p a r a t e l y u s i n g two d i f f e r e n t r e n d e r i n g s o fForm B . The u s e o f t h e t a b l e s w i l l b e i l l u s t r a t e d by r e f e r e n c e t o Case
S t u d y No. 1 which a s Q u i r o u e t t e h a s e x p l a i n e d p e r t a i n s t o a h i g h - r i s e
a p a r t m e n t b u i l d i n g o f a s p e c i f i c c o n f i g u r a t i o n .
The empty columns i n t h e t a b l e a r e a s s i g n e d t o a l l t h o s e t y p i c a l a r e a s o r s p a c e s i n t h e b u i l d i n g where p e o p l e may b e when a f i r e o c c u r s ,
e . g .
,
an a p a r t m e n t s u i t e ( s p e c i f i c a l l y , t h e one on f i r e ) , s p a c e s e l s e -where on t h e f i r e f l o o r , s p a c e s e l s e w h e r e i n t h e b u i l d i n g g e n e r a l l y , s h a f t s i n t e n d e d f o r c i r c u l a t i o n , a n d s o on.
The columns ( b u i l d i n g s p a c e s ) a n d t h e rows ( f i r e p r o t e c t i o n
p r i n c i p l e s ) t o g e t h e r c r e a t e an a r r a y o r m a t r i x o f s m a l l b o x e s . The
i n t e n d e d mode o f use o f t h e a r r a y was t o d e t e r m i n e , by a s k i n g t h e
q u e s t i o n a t t h e f o o t o f t h e t a b l e , w h e t h e r e a c h p r i n c i p l e " c o n t r i b u t e d t t t o t h e l i f e s a f e t y o f t h e o c c u p a n t s o f e a c h t y p i c a l a r e a o r s p a c e , t h u s
f i l l i n g t h e boxes w i t h a f f i r m a t i v e s (YES) and n e g a t i v e s (NO). The b a s i s
o f t h e s e answers was t o b e i n f o r m e d judgement, s u p p o r t e d t o t h e maximum
p o s s i b l e e x t e n t by e x p l i c i t t e c h n i c a l knowledge. Using a s e r i e s o f s u c h
t a b l e s s e q u e n t i a l l y , e a c h t i m e c o n s i d e r i n g s e t s o f f i r s t o n e , t h e n two, t h e n t h r e e a n d s o o n , p r i n c i p l e s combined i n t o a s y s t e m , and e a c h t i m e c o m p l e t i n g a l l t h e a n s w e r s , one was t o b e d i r e c t e d toward s y s t e m s which c o n s t i t u t e d w o r k a b l e l i f e s a f e t y d e s i g n s .
T1E MEANING OF LIFE SAFEn
One c o u l d s u r m i s e t h a t an i d e a l g o a l o f l i f e s a f e t y d e s i g n would b e t o p r e v e n t t h e l o s s o f e v e n one l i f e a n n u a l l y . by f i r e i n Canada, i n a 1 1 b u i l d i n g s , u n d e r a l l i m a g i n a b l e c i r c u m s t a n c e s , r e g a r d l e s s o f c o s t . P r a c t i c a l l y , i t must b e a d m i t t e d t h a t i n some c i r c u m s t a n c e s t h e r e i s no c o n c e i v a b l e way t o f o r e s t a l l t h e l o s s o f a l i f e . B e s i d e s , t h e r e u n d o u b t e d l y e x i s t s some l i m i t o f t o l e r a t i o n t o t h e e x p e n d i t u r e s needed
t o a v e r t l i f e l o s s e s . With r e g r e t , one concedes t h a t s o c i e t y c a n n o t
a f f o r d t o p r o t e c t i t s members a g a i n s t a l l i m a g i n a b l e c i r c u m s t a n c e s .
A p r a c t i c a l g o a l may b e t h o u g h t o f a s o p t i m a l b u i l d i n g f i r e
p r o t e c t i o n - - t h e most economic form o f f i r e p r o t e c t i o n c a p a b l e o f
p r o v i d i n g an a p p r o p r i a t e d e g r e e o f s a f e t y t o t h e o c c u p a n t s o f a b u i l d i n g i f t h e r e i s a f i r e . T h i s r e d e f i n i t i o n s t i l l e v a d e s t h e r e a l q u e s t i o n ,
because t h e meaning o f a n " a p p r o p r i a t e " d e g r e e o f s a f e t y i s n o t made c l e a r . To d i s c o v e r i t , one would b e f o r c e d t o r e - a s k t h e o l d q u e s t i o n s . How s a f e i s s a f e ? Mow s a f e i s s a f e enough? What does s o c i e t y e x p e c t ?
What w i l l s o c i e t y a c c e p t ? What i s a knowledgeable r i s k ? What i s a
r e a s o n a b l e p r e c a u t i o n ? The answers t o t h e s e q u e s t i o n s have y e t t o b e d i s c o v e r e d .
For t h e time b e i n g , t o p r o v i d e m o t i v a t i o n and an o b j e c t i v e f o r t h e s t u d y , t h e f o l l o w i n g h i e r a r c h y of l i f e s a f e t y g o a l s i s p u t forward.
Occupants s h o u l d b e p r o t e c t e d i n p l a c e i f p o s s i b l e , b u t f a i l i n g t h i s i t
s h o u l d b e e n s u r e d t h a t i f anyone i s c a l l e d upon t o l e a v e t h e f i r e l o c a - t i o n o r t h e b u i l d i n g , h e o r s h e c a n do s o i n a n o r d e r l y u n h u r r i e d
manner, which we term e v a c u a t i o n . I t i s n o t d e s i r a b l e t h a t any o c c u p a n t
s h o u l d b e s u b j e c t e d t o t h e need t o e s c a p e
--
t h a t i s , t o d e p a r t i n undueh a s t e b e c a u s e of imminent p e r i l . I t i s n o t t o l e r a b l e t h a t any o c c u p a n t
s h o u l d e v e r have t o r e l y e n t i r e l y upon e x t e r n a l a i d u n d e r e x t r e m e l y
d e s p e r a t e c i r c u m s t a n c e s
-
- t h a t i s , upon r e s c u e .EXECUTING 'ME PROCEDURE FOR SMOKE HAZARDS
These c o n s i d e r a t i o n s prompted r e p l a c e m e n t o f t h e q u e s t i o n a s k e d i n
Form B ( i . e . , w h e t h e r a p r i n c i p l e c o n t r i b u t e d t o l i f e s a f e t y ) by t h e
more p o s i t i v e one o f w h e t h e r t h e p r i n c i p l e o r system under c o n s i d e r a t i o n was p o t e n t i a l l y c a p a b l e , w i t h o u t f u r t h e r a d d i t i o n s , o f p r o v i d i n g a n
a p p r o p r i a t e degree o f s a f e t y . I n a d d i t i o n , t h e r a n g e o f p o s s i b l e
answers was e x t e n d e d by t h e u s e o f a q u e s t i o n mark a s a q u a l i f i e r , t h u s
g i v i n g NO (no promise o f c a p a b i l i t y ) , NO? (dubious p r o m i s e ) , YES?
( p o s s i b l e promise) and YES ( d e f i n i t e promise)
.
The amended t a b l e ( F i g u r e 2) h a s been completed t o show t h e r e s u l t s
o f t h e o p e r a t i o n s which w i l l now b e e x p l a i n e d . Case No. 1 - - h i g h - r i s e
r e s i d e n t i a l - - i s u n d e r s t u d y , and t h e s u b - c a s e s p e c i f i c a l l y examined i s
t h a t o f f i r e o c c u r r i n g i n one o f t h e a p a r t m e n t s u i t e s . For t h e moment, o n l y t h e smoke h a z a r d s a r e c o n s i d e r e d . The s i g n i f i c a n c e of t h e l a b e l s o f t h e v a r i o u s o c c u p i e d s p a c e s must a l s o b e e x p l a i n e d . " S u i t e " i s t h e f i r e s u i t e . "Floor" i s a l l t h e r e s t o f t h e f i r e f l o o r , e x c l u d i n g t h e f i r e s u i t e . "Building" i s a l l t h e r e s t o f t h e b u i l d i n g e x c l u d i n g t h e f i r e f l o o r . Each s p a c e i s t h u s e x c l u s i v e o f t h e l o w e r - s c a l e d s p a c e s t o i t s l e f t i n t h e t a b l e , e x c e p t t h a t " s h a f t " does n o t f i t i n t o t h i s r e l a - t i o n s h i p a n d p e r h a p s s h o u l d have b e e n p l a c e d s e p a r a t e from t h e o t h e r s . F i g u r e 2 was u s e d t o a p p l y t h e q u e s t i o n a b o u t p o t e n t i a l s u f f i c i e n c y t o t h o s e systems t h a t comprised o n l y a s i n g l e one of t h e f o u r t e e n b a s i c
p r i n c i p l e s . The answers were f i l l e d i n v e r y q u i c k l y s i m p l y by i n s p e c t i o n .
The i n t u i t i v e judgements s o made a r e of c o u r s e open t o c h a l l e n g e ,
a l t h o u g h t h e s i t u a t i o n s a r e s o c l e a r c u t t h a t any group o f f i r e t e c h n o l o g y s p e c i a l i s t s would p r o b a b l y e x p e r i e n c e l i t t l e d i f f i c u l t y i n r e a c h i n g
agreement on t h e c o r r e c t answers t o b e e n t e r e d i n t o t h e d e c i s i o n m a t r i x . The r e a s o n i n g b e h i n d t h e i r judgements, which a t t h i s s t a g e might amount t o o n l y a s i m p l e s e n t e n c e o r two f o r each e n t r y i n t h e a r r a y , c o u l d b e
The c o n c l u s i o n t o b e drawn from F i g u r e 2 i s t h a t no s i n g l e f i r e p r o t e c t i o n f e a t u r e , u s e d e n t i r e l y a l o n e , c a n p r o v i d e e f f e c t i v e p r o t e c t i o n
a g a i n s t t h e h a z a r d o f smoke f o r any p e r s o n anywhere i n t h e b u i l d i n g . The
l o g i c a l n e x t s t e p i n s e e k i n g s u p e r i o r p e r f o r m a n c e i s t o examine s y s t e m s c o m p r i s i n g two o f t h e f o u r t e e n b a s i c p r i n c i p l e s . T h e r e i s a v e r y l a r g e number o f s u c h t w o - l e v e l s y s t e m s , and t h e s t r i c t l o g i c o f t h e p r o c e d u r e imposes t h e c o n s i d e r a b l e t a s k o f a s s e s s i n g them a l l b e c a u s e t h e r e i s s o f a r no r a t i o n a l e f o r d e c i d i n g which a r e t h e most p r o m i s i n g p r o s p e c t i v e c o m b i n a t i o n s . For t h e e x p l o r a t o r y p u r p o s e o f t h i s s t u d y i t was d e c i d e d t o examine o n l y t h o s e t w o - l e v e l s y s t e m s c o m p r i s i n g s p r i n k l e r s a s one o f t h e two p r i n c i p l e s . The r e s u l t s o f t h i s e x a m i n a t i o n a r e p r e s e n t e d i n F i g u r e 3. Once a g a i n , t h e s e r e l a t i v e l y s i m p l e s y s t e m s do n o t s u f f i c e t o p r o v i d e a n a p p r o p r i a t e d e g r e e o f s a f e t y t o a l l t h e o c c u p a n t s o f t h e b u i l d i n g . Once a g a i n , documentation c o u l d h a v e b e e n p r e p a r e d t o e x p l a i n t h e r e a s o n i n g b e h i n d each d e c i s i o n . I n p r e p a r i n g t o examine systems c o m p r i s i n g t h r e e p r i n c i p l e s , t h e problem a g a i n a r i s e s t h a t t h e r e i s a v e r y l a r g e number o f s u c h s y s t e m s . Even i f a l l t h o s e n o t i n c l u d i n g s p r i n k l e r s were t e m p o r a r i l y d i s r e g a r d e d , t h e t a s k o f e v a l u a t i n g t h e r e m a i n d e r would s t i l l b e f o r m i d a b l e . For t h e p r e s e n t p u r p o s e , g u i d a n c e f o r f u r t h e r s i m p l i f i c a t i o n was o b t a i n e d
from F i g u r e 3 , where i t can b e s e e n t h a t t h e r e i s p o t e n t i a l l y some
p r o m i s e i n s y s t e m s t h a t combine s p r i n k l e r s w i t h some form o f smoke move-
ment c o n t r o l . The c h o i c e was made t o i n v e s t i g a t e o n l y t h e t h r e e - l e v e l
s y s t e m s t h a t c o n t a i n b o t h t h e s e p r i n c i p l e s .
T h i s method o f c h o o s i n g i n d i c a t e s a p o s s i b l e method o f s i m p l i f y i n g t h e t a s k o f p r e p a r i n g documentation f o r a l l t h e p o s s i b l e c o m b i n a t i o n s o f f o u r t e e n p r i n c i p l e s t a k e n s e v e r a l l y a t a t i m e , e x c e e d i n g t h r e e h u n d r e d
t h o u s a n d i n number. Each s u c c e s s i v e t a b l e might b e used a s o n e s t e p i n
a s e q u e n t i a l s e a r c h p r o c e d u r e which would d i r e c t t h e u s e r toward t h e most p r o m i s i n g s y s t e m s , t h u s p r o v i d i n g r e l e v a n t r e s u l t s a s q u i c k l y a s
p o s s i b l e . The f u n c t i o n a l i m p e r a t i v e s o f a g i v e n occupancy o r a
p a r t i c u l a r b u i l d i n g d e s i g n might p r o v i d e a d d i t i o n a l c o n s t r a i n t s which
would r e d u c e t h e a r e a t o b e s w e p t by t h e s e a r c h p r o c e d u r e . The
d i f f i c u l t y o f t h i s o t h e r w i s e a t t r a c t i v e simp1 i f i c a t i o n i s t h a t many p a t h s which a p p e a r u n s a t i s f a c t o r y i n low- l e v e l t a b l e s might e v e n t u a l l y produce e f f e c t i v e a n d economic s y s t e m s a s a d d i t i o n a l p r i n c i p l e s were
a d d e d . I n a d d i t i o n , t h e o r i g i n a l p r e d e t e r m i n e d c h o i c e o f d e s i g n p a r a - m e t e r s would b e p e r p e t u a t e d , whereas a w i d e r - r a n g i n g p r o c e d u r e m i g h t s u g g e s t v i a b l e a 1 t e r n a t i v e d e s i g n i m p e r a t i v e s . O v e r - s i m p l i f i c a t i o n o f t h e p r o c e d u r e c a n t h u s r e s u l t i n t h e a d o p t i o n o f s u b o p t i m a l s y s t e m s . The t h r e e - l e v e l s y s t e m s shown i n F i g u r e 4 a l l a p p e a r t o p r o m i s e some p o t e n t i a l e f f e c t i v e n e s s i n p r o v i d i n g p r o t e c t i o n a g a i n s t s m k e h a z a r d s t o p e r s o n s o t h e r t h a n t h o s e i n t h e s u i t e where t h e f j . r e
o r i g i n a t e d . The e x p l o r a t o r y s t u d y was n o t c a r r i e d beyond t h i s l e v e l ,
b u t i t i s e v i d e n t t h a t from h e r e on r e a s o n e d argument f o r each d e c i s i o n , and d o c u m e n t a t i o n , would b e e s s e n t i a l t o g u i d e e a c h s u c c e s s i v e c h o i c e o f p a t h i n t h e s e a r c h p r o c e d u r e .
EXECUTING THE PROCEDURE FOR FIRE HAZARDS
The a n a l o g o u s t a b l e f o r a n a l y s i s o f t h e h a z a r d of d i r e c t e x p o s u r e t o
f i r e i s somewhat s m a l l e r ( F i g u r e 5) because two e x c l u s i v e l y s m o k e - r e l a t e d
p r i n c i p l e s have been dropped. I n t h e p r e s e n t c a s e , t h e p r i n c i p l e s l i s t e d
i n t h e t a b l e , and t h e q u e s t i o n a s k e d , r e f e r o n l y t o s p r e a d o f f i r e w i t h i n
t h e b u i l d i n g . A s b e f o r e , t h e d e c i s i o n s f o r t h i s o n e - l e v e l t a b l e were
e n t e r e d i n t o t h e a r r a y v e r y r a p i d l y on t h e b a s i s of i n t u i t i v e judgements. I t a g a i n a p p e a r s t h a t no s i n g l e p r i n c i p l e u s e d a l o n e p r o v i d e s
a p p r o p r i a t e p r o t e c t i o n . This t i m e , however, t h e r e a r e a few q u a l i f i e d
answers i n t h e t o p l i n e ( e . g . , "maybe yes") t h a t s u g g e s t t h e n e x t s t e p i n t h e s e a r c h p r o c e d u r e might w e l l b e t w o - l e v e l s y s t e m s i n c o r p o r a t i n g s p r i n -
k l e r s a s one o f t h e two p r i n c i p l e s . F o l l o w i n g t h i s more p r o m i s i n g d i r e c -
t i o n a s a s h o r t c u t l e a d s t o a t w o - l e v e l a r r a y ( F i g u r e 6) t h a t o f f e r s many more p r o m i s i n g f u r t h e r d i r e c t i o n s t h a n d i d t h e c o r r e s p o n d i n g smoke
t a b l e . The rows c o n t a i n i n g t h e g r e a t e s t a g g r e g a t e promise v a l u e s p r e -
sumably i n d i c a t e t h e most f a v o u r a b l e d i r e c t i o n s , b u t t h e r e i s no c l e a r c u t
c h o i c e . I-Lowever, c i r c u l a t i o n r o u t e s (which c a n a l s o b e u s e d f o r e g r e s s )
a r e one o f t h e f u n c t i o n a l i m p e r a t i v e s o f c o n v e n t i o n a l b u i l d i n g , s o t h e c h o i c e was made ( F i g u r e 7) t o examine t h r e e - l e v e l s y s t e m s combining s p r i n k l e r s and r o u t e s o f e g r e s s w i t h any one o t h e r p r i n c i p l e .
I n t h i s new d e c i s i o n a r r a y t h e r e a r e two q u i t e p r o m i s i n g s y s t e m s ,
i n d i c a t e d by a r r o w s . I n p a r t i c u l a r , i t l o o k s a s though s y s t e m s h a v i n g
s p r i n k l e r s and e g r e s s r o u t e s p l u s a l a r m systems may b e p o t e n t i a l l y
s u f f i c i e n t t o a s s u r e s a f e t y o f a l l o c c u p a n t s o f t h e b u i l d i n g a g a i n s t t h e h a z a r d o f d i r e c t e x p o s u r e t o f i r e o r i g i n a t i n g i n a s u i t e . The d e c i s i o n s a r e o f c o u r s e s t i l l o n l y s n a p judgements; i f documentation had been p r e p a r e d t h e accompanying r e a s o n e d a s s e s s m e n t s might v e r y l i k e l y have r e s u l t e d i n a d i f f e r e n t , and p e r h a p s l e s s p r o m i s i n g , l i n e - u p o f d e f i n i t e o r q u a l i f i e d a f f i r m a t i v e s and n e g a t i v e s .
COMBINING THE SMOKE A N D FIRE SYSTEM3
The f i r e p r o t e c t i o n d e s i g n f i n a l l y a d o p t e d must b e c a p a b l e o f a c h i e v i n g a l l t h e o b j e c t i v e s s p e c i f i e d by b o t h t h e smoke and f i r e
a n a l y s e s . When t h e two s y s t e m s comprise t h e same o r n e a r l y t h e same l i s t
o f p r i n c i p l e s , b u t wi.th d i f f e r i n g i n t e n s i t i e s , i t i s mainly a m a t t e r o f
e n s u r i n g t h a t a l l t h o s e p r i n c i p l e s a r e p r e s e n t i n t h e f i n a l d e s i g n and t h a t each i s a p p l i e d a t t h e h i g h e s t i n t e n s i t y c a l l e d f o r by e i t h e r o f t h e
two s y s t e m s . T h i s p r o c e s s i s analogous t o t h a t o f meeting t h e most
r e s t r i c t i v e r e q u i r e m e n t s i n c o n v e n t i o n a l c o d e - t y p e d e s i g n .
On t h e o t h e r hand, when t h e l i n e - u p s o f p r i n c i p l e s i n t h e two systems a r e d i s s i m i l a r , t h e s y n t h e t i c a l l i n e o f a t t a c k j u s t mentioned c o u l d l e a d t o o v e r d e s i g n o r redundancy i n t h e f i r e p r o t e c t i o n p l a n , b e c a u s e p r i n c i p l e s c a l l e d f o r by o n l y o n e s y s t e m may i n f a c t b e perform- i n g a l s o some f u n c t i o n s which a r e s e r v e d by e n t i r e l y d i f f e r e n t p r i n c i p l e s r e q u i r e d by t h e o t h e r system. The c o n c e p t o f e q u a t i n g f i r e h a z a r d a t t r i b u t e s and f i r e p r o t e c t i o n p r i n c i p l e a t t r i b u t e s , p r o p o s e d by Q u i r o u e t t c , c o u l d b e a p p l i e d w i t h c o n s i d e r a b l e e f f e c t h e r e , t o d e t e r m i n e
which p r i n c i p l e s a r e p e r f o r m i n g l i k e f u n c t i o n s and t h u s l e a d t o o p t i m i z a t i o n o f t h e s y n t h e s i z e d d e s i g n .
THE S I GNI FI CANCE OF DOCUMENTATION
The p r i m a r y p u r p o s e o f t h e documentation p r o c e s s i s t o f o r c e
r e a s o n e d a s s e s s m e n t o f t h e arguments f o r and a g a i n s t e a c h d e c i s i o n , i n v o k i n g a t t h e same t i m e a t l e a s t some awareness o f t h e g o a l s o f t h e
f i r e p r o t e c t i o n d e s i g n and t h e h a z a r d s and f a c t o r s i n v o l v e d . These
i m p l i c i t c o n s i d e r a t i o n s , which Q u i r o u e t t e s u b s e q u e n t l y made much more e x p l i c i t by h i s i n t r o d u c t i o n o f t h e c o n c e p t o f a t t r i b u t e s , c o u l d b e e x p r e s s e d i n q u e s t i o n s s u c h a s "What a r e t h e h a z a r d s t o which a p e r s o n
i n t h i s ( c u r r e n t l y b e i n g c o n s i d e r e d ) s p a c e i s exposed?", "What a r e h i s
t r u e n e e d s i n t e r m s o f f i r e p r o t e c t i o n ? " , "What a r e t h e q u a l i t i e s ( i . e . ,
a t t r i b u t e s ) t h a t t h i s o r t h a t p r i n c i p l e can c o n t r i b u t e t o p r o v i d e
p r o t e c t i o n a g a i n s t t h e h a z a r d s ? " Documentation t e n d s t o promote commn-
s e n s e t h i n k i n g b a s e d on f a c t u a l i n f o r m a t i o n r a t h e r t h a n e m o t i o n . I t c a n
a l s o promote awareness o f a r e a s where i n f o r m a t i o n i s d e f i c i e n t o r
1 a c k i n g
.
THE INTENSITY PROFILE OF A SYSTEM
P r o j e c t i n g a l i t t l e f u r t h e r t h e d e c i s i o n a r r a y m a n i p u l a t i o n s d i s c u s s e d e a r l i e r , one c a n v i s u a l i z e t h e outcome a s b e i n g , p e r h a p s , t h a t f o r a g i v e n b u i l d i n g s u f f i c i e n t s a f e t y i s p r o v i d e d by a p a r t i c u l a r f i v e - l e v e l s y s t e m c o m p r i s i n g a c e r t a i n s e t o f p r i n c i p l e s . T h i s would b e a m i s l e a d i n g l y o v e r s i m p l i f i e d s t a t e m e n t , b e c a u s e any o r a l l o f t h e p r i n c i p l e s i n v o l v e d might b e c a p a b l e o f b e i n g a p p l i e d w i t h
a r a n g e o f d e g r e e s o f d e t e r m i n e d n e s s ( i n t e n s i t y ) , some o f which would
f a l l below t h e d e g r e e needed f o r e f f e c t i v e p e r f o r m a n c e . For example,
s i m p l y t o mention t h e p r i n c i p l e " f i r e r e s i s t a n c e " i g n o r e s t h e f a c t t h a t
t h i s p r i n c i p l e c a n b e a p p l i e d w i t h i n t e n s i t i e s r a n g i n g from 1 5 o r 20
minutes e x p o s u r e t o t h e s t a n d a r d f i r e t e s t , a t t h e low end, t o 8 o r even
16 h o u r s a t t h e h i g h e n d . For any g i v e n p u r p o s e , a l l i n t e n s i t i e s o f a p p l i c a t i o n below a c e r t a i n l e v e l ( s a y 2 h o u r s ) w i l l f a i l t o p r o v i d e t h e d e s i r e d p e r f o r m a n c e , w h i l e i n t e n s i t i e s a t o r above t h a t l e v e l w i l l p r o v i d e t h e d e s i r e d performance o r b e t t e r . E v i d e n t l y e a c h p r i n c i p l e must b e a p p l i e d w i t h an i n t e n s i t y commen- s u r a t e w i t h t h e h a z a r d a g a i n s t which i t p r o v i d e s p r o t e c t i o n . Any l e s s e r
i n t e n s i t y w i l l b e u n a c c e p t a b l e from t h e l i f e s a f e t y p o i n t o f view; any
h i g h e r l e v e l (even i f o v e r d e s i g n e d o r e x c e s s i v e l y c o s t l y ) w i l l b e
a c c e p t a b l e b e c a u s e one i s s u r e o f a c h i e v i n g a t l e a s t t h e d e s i r e d d e g r e e
o f s a f e t y , (Each p r i n c i p l e , o f c o u r s e , p o s s e s s e s o n e o r more a t t r i b u t e s ,
e a c h o f which c o n t r i b u t e s p r o t e c t i o n a g a i n s t one o r more d i f f e r e n t t y p e s
o f h a z a r d s . E f f e c t i v e p r o t e c t i o n a g a i n s t a g i v e n h a z a r d i s t h e s u m - t o t a l
r e s u l t o f p a r t i a l p r o t e c t i o n p r o v i d e d s e p a r a t e l y by s e v e r a l p r i n c i p l e s
p o s s e s s i n g a common a t t r i b u t e r e l e v a n t t o t h a t h a z a r d . One c a n p e r c e i v e
o t h e r ways i n which p r i n c i p l e s i n t e r a c t t o p r o v i d e s u p e r i o r l e v e l s o f
p r o t e c t i o n . Thus t h e remarks a b o u t i n t e n s i t i e s made e a r l i e r i n t h i s and
i t i s t h e t o t a l i n t e n s i t y w i t h which a given a t t r i b u t e must b e a p p l i e d t h a t d e t e r m i n e s t h e needed i n t e n s i t i e s o f t h e c o n t r i b u t i n g p r i n c i p l e s . )
Suppose t h a t t h e i n t e n s i t i e s w i t h which each p r i n c i p l e can b e
a p p l i e d c a n be q u a n t i f i e d i n some manner on an a r b i t r a r i l y d e f i n e d s c a l e
running from one t o t e n . Any p a r t i c u l a r f i r e p r o t e c t i o n system can t h e n
b e r e p r e s e n t e d by a b a r c h a r t ( F i g u r e 8) i n which e a c h b a r r e p r e s e n t s
one o f t h e c o n s t i t u e n t p r i n c i p l e s of t h e s y s t e m and t h e l e n g t h o f t h e b a r r e p r e s e n t s t h e i n t e n s i t y w i t h which t h a t p r i n c i p l e i s a p p l i e d i n t h e
system. Every system w i l l have a unique c h a r t : i t s i n t e n s i t y p r o f i l e .
The r e s u l t s o f t h e a s s e s s m e n t and documentation p r o c e s s c a n t h u s b e
summarized i n p r o f i l e form. P r o f i l e s can b e c o n s t r u c t e d f o r g e n e r a l i z e d
systems, p r o d u c i n g something a k i n t o a b u i l d i n g code, o r f o r s p e c i f i c b u i l d i n g d e s i g n p r o p o s a l s .
PRACTICAL USES OF
?HE
PROCEDURESome p o s s i b l e a p p l i c a t i o n s o f t h e i n t e n s i t y p r o f i l e i d e a have been
e x p l o r e d a n d w i l l now b e d i s c u s s e d . I t i s assumed t h a t f o r a p a r t i c u l a r
g e n e r a l i zed b u i l d i n g occupancy and c o n f i g u r a t i o n a l l t h e workable s y s tems have been i d e n t i f i e d , t h e a p p r o p r i a t e i n t e n s i t i e s have been a s s e s s e d f o r
t h e c o n s t i t u e n t p r i n c i p l e s o f each system, a n d a l l t h e documentation h a s
been p r e p a r e d . The r e s u l t i s a v a s t l i b r a r y o f p r o f i l e s , which can b e
s o r t e d and matched e n d l e s s l y a c c o r d i n g t o any needs t h a t a r i s e . The l i b r a r y c o n s t i t u t e s a b u i l d i n g code c o n t a i n i n g a l l t h e a c c e p t a b l e f i r e
s a f e t y d e s i g n s f o r t h e chosen occupancy and c o n f i g u r a t i o n . P r o f i l e s o f
a l l t h e u n a c c e p t a b l e d e s i g n s (which n e c e s s a r i l y have been examined a n d r e j e c t e d d u r i n g t h e a s s e s s m e n t p r o c e d u r e ) c o u l d a l s o b e f i l e d , i n t h i s o r a n o t h e r l i b r a r y .
P o s s i b l e A T I ~ l i ~ a t i 0 n ~
1 . The two p r o f i l e s shown i n F i g u r e 9 o b v i o u s l y came from t h e same
s h e l f i n t h e l i b r a r y . Both systems have a l r e a d y been through t h e e n t i r e
a s s e s s m e n t p r o c e d u r e and have been judged s u f f i c i e n t . However, i t w i l l
b e s e e n t h a t t h e t o p p r i n c i p l e , w h a t e v e r i t may b e , i s a p p l i e d w i t h l e s s i n t e n s i t y i n t h e second system, w h i l e t h e bottom p r i n c i p l e i s a p p l i e d
more i n t e n s e l y . T h i s means t h a t t h e o u t l i n e d a r e a a t t h e t o p h a s been
exchanged a g a i n s t t h e shaded a r e a a t t h e bottom.
To t h e e x t e n t t h a t t h e two s y s tems p r o v i d e comparable p r o t e c t i o n ,
t h i s i s a t r u e t r a d e o f f . I n p r a c t i c e , one may b e an o p t i m a l system,
p r o v i d i n g j u s t enough p r o t e c t i o n , w h i l e t h e o t h e r p r o v i d e s more t h a n i s
e s s e n t i a l . The b u i l d i n g d e s i g n e r , knowing t h a t b o t h have p a s s e d t h e
a s s e s s m e n t t e s t , h a s t h e freedom t o choose whichever of t h e s e
- -
o rt h e i r n e a r r e l a t i v e s
- -
i s more economic o r s u i t a b l e f o r h i s p r o p o s e db u i l d i n g .
2 . I n t h e same s i t u a t i o n a s above, t h e d e s i g n e r may have c o n s t r u c t e d
t h e p r o f i l e f o r h i s own proposed f i r e s a f e t y d e s i g n , a n d found t h a t i t
F i g u r e 9 most n e a r l y match h i s own. The documentation f o r t h e two n e a r matches t h e n p r o v i d e s him w i t h a sound b a s i s f o r a s e s s i n g what changes
( i f any) may b e n e c e s s a r y i n h i s p r o p o s a l .
3 . The two systems whose p r o f i l e s a r e shown i n F i g u r e 10 a r e a g a i n a l m o s t l o o k - a l i k e s , e x c e p t t h a t i n t h e s e c o n d p r o f i l e one p r i n c i p l e h a s been o m i t t e d ( s p r i n k l e r s ) and a n o t h e r , u n s p e c i f i e d , s u b s t i t u t e d f o r i t . S i n c e b o t h s y s t e m s a r e assumed t o have been s u b j e c t e d t o t h e a s s e s s m e n t p r o c e d u r e , and s i n c e b o t h have been judged s u f f i c i e n t , F i g u r e 10
r e p r e s e n t s a n o t h e r t y p e o f t r a d e o f f .
4. There a r e many d i f f e r e n c e s between t h e two s y s t e m s shown i n F i g u r e
11 - - t h e y come from e n t i r e l y d i f f e r e n t s h e l v e s i n t h e l i b r a r y o f
p r o f i l e s - - s o t h e y a r e n o t r e a l l y q u i t e comparable. A d e s i g n e r might
f i n d , however, t h a t one o r t h e o t h e r o f f e r e d w o r t h w h i l e economies and he
might choose t o modify h i s d e s i g n a c c o r d i n g l y . T h i s , t o o , i s a t y p e o f
t r a d e o f f , b u t , more i m p o r t a n t , t h e d e s i g n e r i s c o n s c i o u s l y u s i n g t h e l i b r a r y a s a f r u i t f u l and comprehensive s o u r c e o f d e s i g n i n i t i a t i v e s .
5 . I n n o v a t i v e d e s i g n s , r e s e m b l i n g n o t h i n g e v e r p r e v i o u s l y c o n s t r u c t e d ,
o f t e n pose problems f o r f i r e and code o f f i c i a l s b e c a u s e t h e y a p p e a r t o i n c o r p o r a t e many c o n t r a v e n t i o n s o f c o n v e n t i o n a l l y a c c e p t e d c o d i f i e d
d e s i g n p r i n c i p l e s . Lacking p r e c e d e n t , and l a c k i n g a c o h e r e n t o r g a n i z e d
body o f knowledge a b o u t f i r e s a f e t y , o f f i c i a l s t e n d t o impose c o n s e r v a -
t i v e and r e s t r i c t i v e r e q u i r e m e n t s on t h e i n n o v a t i v e d e s i g n . S u g g e s t i o n s
t h a t t h e s e i m p o s i t i o n s sometimes seem c o m p l e t e l y a r b i t r a r y imply f a u l t s , n o t i n t h e o f f i c i a l s , b u t i n t h e code-making and r e g u l a t i n g p r o c e s s
i t s e l f and i n t h e s u p p o r t s e r v i c e s p r o v i d e d f o r t h e o f f i c i a l s .
The i n t e n t o f F i g u r e 1 2 i s t o show t h a t t h e documentation a s s o c i a t e d
w i t h t h e l i b r a r y o f p r o f i l e s can b e used by b o t h s i d e s , t h e d e s i g n e r o r owner and t h e o f f i c i a l s , a s a common b a s e o f knowledge f o r r e s o l v i n g
d i f f e r e n c e s a b o u t t h e f i r e s a f e t y o f i n n o v a t i v e d e s i g n s . I t i s supposed
t h a t a p r o f i l e o f t h e proposed i n n o v a t i v e d e s i g n h a s been c o n s t r u c t e d , u s i n g t h e l i b r a r y documentation a s a p r o c e d u r a l g u i d e , and t h a t t h e l i b r a r y h a s been s e a r c h e d f o r t h e j u d g e d - e f f e c t i v e p r o f i l e t h a t most
c l o s e l y matches t h e p r o p o s e d one. Any d e v i a t i o n s between t h e two pro-
f i l e s t h e n become c l e a r l y e v i d e n t , and t h e consequences o f t h e d e v i a t i o n s can be d i s c u s s e d u n e q u i v o c a l l y i n t h e l i g h t o f t h e documentation o f t h e l i b r a r y p r o f i l e .
SYSTEMS SUB,JECT TO STATISTICAL FAILURE
Most f i r e p r o t e c t i o n p r i n c i p l e s a r e a t l e a s t s l i g h t l y s u s c e p t i b l e t o random f a i l u r e when c a l l e d upon t o p e r f o r m , whether through p o o r d e s i g n , c a r e l e s s i n s t a l l a t i o n , f a u l t y maintenance, human e r r o r o r p u r e
bad l u c k (which we c a l l c h a n c e ) . A s u f f i c i e n t l y s a f e system t h e n can
become a p o t e n t i a l l y u n s a f e one, by r e a s o n o f t h e f a i l u r e o f one p r i n c i p l e t o p e r f o r m a s e x p e c t e d .
The i m p l i c a t i o n s o f such s i t u a t i o n s a r e sometimes d e l i b e r a t e l y o v e r l o o k e d , a s when e x c e s s i v e c o n c e s s i o n s o r u n l i m i t e d t r a d e o f f s a r e
a l l o w e d when a b u i l d i n g i s f u l l y s p r i n k l e r e d . On t h e o t h e r hand, i t i s u n r e a l i s t i c t o a t t e m p t t o d e s i g n on a c o m p l e t e l y s t a t i s t i c a l b a s i s , u s i n g t h e v a r i o u s methods o f p r o b a b i l i s t i c a n a l y s i s o f f i r e s a f e t y , b e c a u s e much o f t h e n e c e s s a r y s t a t i s t i c a l d a t a b a s e o f s u c h a n a l y s e s i s e s s e n t i a l l y u n a v a i l a b l e . A p h i l o s o p h i c a p p r o a c h w i l l now b e p r e s e n t e d which, a l t h o u g h i n g e n u o u s , i s a s a t i s f a c t o r y v e h i c l e f o r r i g o r o u s a p p r a i s a l o f random- f a i l u r e s i t u a t i o n s . Take t h e c a s e o f a s i x - l e v e l s y s t e m i n c o r p o r a t i n g s p r i n k l e r s i n which, f o r o n e r e a s o n o r a n o t h e r , t h e s p r i n k l e r s f a i l t o p e r f o r m a s e x p e c t e d . The s y s t e m i s t h e n , i n e f f e c t , d e g r a d e d t o a f i v e - l e v e l s y s t e m ( F i g u r e 13) whose p r o f i l e c a n b e matched a g a i n s t t h o s e i n t h e
l i b r a r y . The d o c u m e n t a t i o n b e l o n g i n g t o t h e matches might show t h a t t h e
p r o f i l e s t i l l r e p r e s e n t e d a s y s t e m c a p a b l e o f a c h i e v i n g t h e d e s i r e d d e g r e e o f s a f e t y , b u t o n e would e x p e c t t h e more u s u a l r e s u l t t o b e t h a t t h e b e s t - m a t c h i n g p r o f i l e h a d p r e v i o u s l y been a s s e s s e d a s i n s u f f i c i e n t .
The q u e s t i o n t h e n a r i s e s
- -
and t h i s must b e a p o l i c y d e c i s i o n - -g i v e n t h e o b j e c t i v e o f s a v i n g a l l l i v e s , a n d g i v e n t h a t i n a s t a t i s t i -
c a l l y known p r o p o r t i o n o f f i r e i n c i d e n t s t h e s p r i n k l e r s w i l l f a i l t o
p e r f o r m a s e x p e c t e d , i s one w i l l i n g t o a c c e p t t h e r e d u c e d d e g r e e o f
s a f e t y o f t h e f i v e - l e v e l s y s t e m on t h o s e few o c c a s i o n s when t h e s p r i n k - l e r s may f a i l ? I n o t h e r words, what d i m i n i s h e d o b j e c t i v e may one
r e a s o n a b l y s e t f o r t h e d i m i n i s h e d s y s t e m ?
SUGGESTED POLICIES FOR LIFE SAFETY
A p o s s i b l e r a t i o n a l e f o r e s t a b l i s h i n g d i m i n i s h e d o b j e c t i v e s f o l l o w s
t h e s a f e t y h i e r a r c h y mentioned e a r l i e r : protect-in-place/evacuate/ e s c a p e / r e s c u e , e a c h o f f e r i n g a g r e a t e r l i k e l i h o o d o f l i f e l o s s t o t h o s e i n v o l v e d .
Given t h e o b j e c t i v e o f p r o t e c t i n g e v e r y o n e i n p l a c e ( F i g u r e 1 4 ) ,
t h e n p a r t f a i l u r e o f one p r i n c i p l e , o r more s e r i o u s f a i l u r e o f one o r more p r i n c i p l e s , o r f a i l u r e o f t h e e n t i r e l i f e s a f e t y s y s t e m , p r o g r e s - s i v e l y e x p o s e more a n d more p e o p l e t o p r o g r e s s i v e l y g r e a t e r h a z a r d , e s c a l a t i n g them downward i n t h e s a f e t y h i e r a r c h y . I t i s s u g g e s t e d t h a t t h e b a s i c p o l i c y s h o u l d b e t h a t a c c e p t a b l e p r o f i l e s must b e s u c h t h a t no t y p e o f p a r t i a l f a i l u r e can s u b j e c t l a r g e numbers o f p e o p l e t o t h e l e v e l s o f p e r i l r e p r e s e n t e d by e s c a p e o r r e s c u e c o n d i t i o n s . A number o f p r o h i b i t e d c o n s e q u e n c e s can t h e n b e i d e n t i f i e d
( b a r r e d i n t h e F i g u r e ) . Small numbers o f p e o p l e , such a s t h o s e i n one
a p a r t m e n t s u i t e , c o u l d c o n c e i v a b l y b e allowed t o be s u b j e c t e d t o e s c a p e o r r e s c u e c i r c u m s t a n c e s , b u t t h e r e must b e f u l l awareness t h a t such a
d e c i s i o n i m p l i e s t h e p o l i c y commitment t h a t t h o s e l i v e s w i l l p o t e n t i a l l y
b e p l a c e d i n s e r i o u s r i s k whenever a s t a t i s t i c a l f a i l u r e o c c u r s i n one
o r a n o t h e r p r i n c i p l e . T h i s t h e n g i v e s r i s e t o a p r o h i b i t e d o b j e c t i v e
t h o s e c a s e s where i t m u s t b e r e a l i s t i c a l l y a d m i t t e d t h a t e f f e c t i v e
p r o t e c t i o n i s t e c h n i c a l l y o r e c o n o m i c a l l y n o t f e a s i b l e .
ADVANTAGES OF THE LIFE SAFETY DESIGN ASSESSMENT PROCEDURE For code w r i t e r s
-
a i d s i n i d e n t i f y i n g e v e r y u s a b l e combination of f i r e p r o t e c t i o np r i n c i p l e s
- encourages use o f knowledge and r e a s o n e d a s s e s s m e n t i n making
d e c i s i o n s a b o u t which c o m b i n a t i o n s p r o v i d e an a c c e p t a b l e l e v e l
o f l i f e s a f e t y
-
promotes c o n s c i o u s awareness o f t h e t r u e o b j e c t i v e s o f l i f es a f e t y r e g u l a t i o n
- promotes c o n s c i o u s awareness o f where knowledge i s l a c k i n g a n d
what knowledge i s l a c k i n g
- e n c o u r a g e s permanent r e c o r d , ("documentationtt) o f t h e r e a s o n i n g
b e h i n d e a c h d e c i s i o n and e a c h c h o i c e .
For d e s i ~ n e r s and build in^ o f f i c i a l s
- p r o v i d e s a c a r d - i n d e x o r l i b r a r y f u n c t i o n ( t h e p r o f i l e s ) t o
a i d i n comparing p r o p o s e d d e s i g n s w i t h s y s t e m s known t o a f f o r d an a c c e p t a b l e o r s u p e r i o r l e v e l o f s a f e t y
- by r e f e r e n c e t o t h e d o c u m e n t a t i o n , promotes r a t i o n a l and i n f o r m e d
n e g o t i a t i o n o v e r d e s i g n p r o p o s a l s which d i f f e r from any a c c e p t e d s y s tem
- a i d s i n t h e i d e n t i f i c a t i o n and a s s e s s m e n t o f s o - c a l l e d t r a d e o f f s .
WEAKNESSES OF THE LIFE SAFETY DESIGN ASSESSMENT PROCEDURE
T h i s p r o c e d u r e h a s b e e n p r e s e n t e d a s a s t a g e w i s e p r o c e s s . The
p r e s e n t a t i o n h a s been l a r g e l y c o n c e p t u a l r a t h e r t h a n c o n c r e t e , d e s c r i b i n g what e a c h s t a g e i s i n t e n d e d t o do r a t h e r t h a n how i t would a c t u a l l y work
i n p r a c t i c e . The l i n k s between s t a g e s have b e e n h a n d l e d i n a s i m i l a r l y
f a c i l e f a s h i o n . F u r t h e r , s t r u c t u r e s needed t o i n c o r p o r a t e t h e a t t r i b u t e
c o n c e p t i n t o t h e p r o c e d u r e have b e e n a l l u d e d t o b u t n o t d e v e l o p e d .
The dominant weakness o f t h e p r o c e d u r e a s d e s c r i b e d i s t h e s e e m i n g l y i n e s c a p a b l e n e c e s s i t y t o s y s t e m a t i c a l l y p e r f o r m a s s e s s m e n t s on a 1 1
p r i n c i p l e - i n t e n s i t y p r o f i l e s f o r a l l t y p i c a l b u i l d i n g c o n f i g u r a t i o n s i n
a l l o c c u p a n c i e s . ?he t a s k i s n o t merely f o r m i d a b l y l a r g e ; i t i s
i m p o s s i b l e . P e r h a p s , i f a s t a r t were made, v a l i d s h o r t - c u t s might
g r a d u a l l y b e d i s c e r n e d o r ways found f o r a p p l y i n g r e s u l t s o b t a i n e d f o r one c o n f i g u r a t i o n o r occupancy t o a n o t h e r , b u t t h e s e a r e by n o means
INCORPORATING ?FIE A l T R I BUTE CONCEPT
The a t t r i b u t e c o n c e p t seems t o o f f e r a way o u t o f t h i s dilemma.
(1) I t seems a l m o s t c e r t a i n t h a t g e n e r a l i z e d r u l e s c o u l d b e d e v i s e d f o r
c o n s t r u c t i n g t h e a t t r i b u t e - i n t e n s i t y p r o f i l e r e q u i r e d by a s p e c i f i c d e s i g n p r o p o s a l f o r any p a r t i c u l a r combination of occupancy a n d b u i l d i n g c o n f i g u r a t i o n .
( 2 ) I t seems a l m o s t c e r t a i n t h a t r u l e s c o u l d b e d e v i s e d f o r c o n s t r u c t i n g
t h e s u m - t o t a l a t t r i b u t e p r o f i l e o f any p r o p o s e d f i r e s a f e t y system.
( 3 ) I t seems p r o b a b l e t h a t t h e r e s u l t s o f 1 a n d 2 c o u l d b e e x p r e s s e d on
a common b a s i s . The a s s e s s m e n t p r o c e d u r e would t h e n b e s i m p l y o n e
o f comparing t h e s e two a t t r i b u t e p r o f i l e s and v a r y i n g t h e occupancy/ c o n f i g u r a t i o n c o n d i t i o n s and t h e f i r e s a f e t y d e s i g n u n t i l t h e p r o f i l e s matched.
( 4 ) A more a t t r a c t i v e and s i m p l e r p r o c e d u r e would b e a v a i l a b l e i f g e n e r a l i z e d r u l e s c o u l d b e d e v i s e d f o r c o n s t r u c t i n g p r i n c i p l e - i n t e n s i t y p r o f i l e s t h a t s a t i s f y t h e r e q u i r e d a t t r i b u t e p r o f i l e - -
t h a t i s , t h e i n v e r s e o f p r o c e s s 2 mentioned above.
( 5 ) P r o c e s s 2 would n e c e s s i t a t e development o f r u l e s f o r w e i g h t i n g t h e
c o n t r i b u t i o n o f each p r i n c i p l e i n a s y s t e m t o each e l e m e n t o f t h e a t t r i b u t e p r o f i l e . Each w e i g h t i n g f a c t o r would presumably depend on what o t h e r p r i n c i p l e s were p r e s e n t i n t h e s y s t e m and t h e
i n t e n s i t i e s w i t h which t h e y were a p p l i e d . (6) P r o c e s s 4 would c a l l f o r r u l e s by which a r e q u i r e d a t t r i b u t e - i n t e n s i t y p r o f i l e c o u l d b e decomposed t o y i e l d a l l t h e p o s s i b l e p r i n c i p l e - i n t e n s i t y p r o f i l e s c a p a b l e o f s a t i s f y i n g t h e a t t r i b u t e r e q u i r e m e n t s ; knowledge o f t h e w e i g h t i n g f a c t o r s would s t i l l b e n e c e s s a r y . I f t h e s e o p e r a t i o n s c o u l d b e computer-programmed, a s a p p e a r s l i k e l y , a n e f f e c t i v e d e s i g n t o o l would r e s u l t : t h e d e s i g n e r c o u l d r e a d i l y i n s e r t h i s own c o n s t r a i n t s and c o u l d v a r y h i s d e s i g n r e q u i r e m e n t s a t w i l l , o b t a i n i n g a s o u t p u t a l i m i t e d range o f s o l u t i o n s h i g h l y r e l e v a n t t o h i s n e e d s . The p o s s i b i l i t y o f c o n f l i c t w i t h r e g u l a t o r y o f f i c i a l s i s s t i l l p r e s e n t i n e x e c u t i o n o f t h e i n i t i a l s t e p (1) o f d e t e r m i n i n g t h e a t t r i b u t e - i n t e n s i t y r e q u i r e m e n t s o f a s p e c i f i c d e s i g n p r o p o s a l . DEFINING RESEARCH AND STUDY NEEDS
The numbered p r o c e s s e s above i d e n t i f y a r e a s where r e s e a r c h o r s t u d y
would b e needed f o r d e v e l o p i n g t h e s e m o d i f i e d p r o c e d u r e s . The develop-
ment t a s k would b e l e s s f o r m i d a b l e t h a n t h a t f o r t h e o r i g i n a l p r o c e d u r e b e c a u s e g e n e r a l i z e d r u l e s a r e s o u g h t r a t h e r t h a n a l i b r a r y o f i n d i v i d u a l
a s s e s s m e n t s and b e c a u s e t h e t a s k i s b r o k e n down i n t o s e v e r a l l a r g e l y
i n d e p e n d e n t a r e a s which c o u l d b e t a c k l e d s e p a r a t e l y . F u r t h e r , t h e
o r i g i n a l judgement and documentation p r o c e s s , which was h i g h l y d e t a i l e d
and f a c t u a l and might w e l l have h a d t o have a c o m m i t t e e - t y p e t r e a t m e n t ,
amenable t o a n a l y t i c t r e a t m e n t by t e c h n i c a l s p e c i a l i s t s . The r e s e a r c h e f f o r t r e q u i r e d would t h u s b e f a r l e s s e x t e n s i v e , and t h e t a s k c o u l d b e t a c k l e d p i e c e w i s e o v e r a l o n g p e r i o d and y e t y i e l d d e f i n i t e r e s u l t s
w h i l e s t i l l i n c o m p l e t e .
The comments o n t h e p r a c t i c a l employment o f t h e a t t r i b u t e c o n c e p t
l a r g e l y echo t h o s e o f Q u i r o u e t t e . They a r e s t i l l e n t i r e l y c o n c e p t u a l ,
b u t p r o v i d e a good g u i d e t o e s t a b l i s h i n g a d e t a i l e d s c h e d u l e o f r e s e a r c h
a n d s t u d y n e e d s . Some o f t h e most i m p o r t a n t needs a r e a s f o l l o w s :
I d e n t i f y t h e p m t e c t i v e a t t r i b u t e r e q u i r e m e n t s imposed by t h e h a z a r d s t o which b u i l d i n g o c c u p a n t s may b e s u b j e c t e d ; f i n d o u t how t o q u a n t i f y a t t r i b u t e i n t e n s i t y r e q u i r e m e n t s , p r o b a b l y i n r e l a t i o n t o t h e t y p e o f s p a c e t h e o c c u p a n t i s i n and t h e b u i l d i n g c o n f i g u r a t i o n ; i d e n t i f y , and l e a r n how t o q u a n t i f y , t h e a t t r i b u t e c o n t r i b u t i o n s o f f i r e p r o t e c t i o n p r i n c i p l e s o f v a r y i n g i n t e n s i t i e s ; d i s c o v e r how t o weigh t h e a t t r i b u t e c o n t r i b u t i o n s o f t h e s e v e r a l p r i n c i p l e s i n a s y s t e m s o a s t o d e t e r m i n e t h e n e t e f f e c t i v e a t t r i b u t e p m f i l e o f t h e e n t i r e s y s t e m .
Each o f t h e s e i s s m a l l enough and s p e c i f i c enough t o t a c k l e c o m f o r t a b l y , y e t e a c h i s a v i t a l p a r t o f d e v e l o p i n g t h e m o d i f i e d a s s e s s m e n t p r o c e d u r e .
CONCLUDING REMARKS
The a t t r i b u t e c o n c e p t g i v e s p r o m i s e t h a t i t can b e worked up i n t o an
e f f e c t i v e d e s i g n t o o l . The f i r s t s t e p toward t h i s end would b e t o d e f i n e
t h e e l e m e n t s o f a r e s e a r c h and s t u d y program t o d e v e l o p t h e t o o l .
E x i s t i n g programs c o u l d t h e n p o s s i b l y a c c o m m d a t e some o f t h e s e e l e m e n t s w i t h o u t m a j o r s h i f t s i n r e s o u r c e s , g i v i n g a s u s t a i n e d l o w - l e v e l o u t p u t on
t h i s p r o j e c t w i t h o u t t h e need t o d e d i c a t e any manpower e x c l u s i v e l y t o i t .
Reference
1 . Q u i r o u e t t e , R. L . Toward a F i r e P r o t e c t i o n P l a n n i n g Approach.
I . Concepts a n d Development. DBR I n t e r n a l R e p o r t No. 418,
FORM Haeard c h a m c t e r i s t i c a n d e r o o n s i d e m t i o n i s CASE STUDY # F i g u r e 1 i ' l r c - r o s i s t i v c B a s i c Form B
-
F i r e P r o t e c t i o n A n a l y s i s C o n s t r u c t i o n I : ] u m o sp r o o d I ' r o s r u r i z ~ ~ t l o n o f ? I ] l U C L ~ 1,1111lr11rlo11 o r I:i r o l o ~ ~ d Non-L:orn!iu.rt i l l I c [ : o 1 1 ~ r r11c t i 011 Smkc ( : o l l t r o I ML.IIRII~~R1
A1 t c r ~ i i l r l vc c*grcss r o u t e d r s i g ~ i Arc11 a t ' r c f u g c L:ollccllt l l c r ~ % ~ . t i o i i ti 111 :IYIII S\..;t Clll. I L'onulil~lr I i 011 5 , < t "!;I< I ,l\l~..l I I ,,I1 ;, \,IIIIIIII.I~.I~~\C ~I.III< \ v , Ill', 1 , \ \ .t~~lll.. I IHAZARD C H A R A C T E R I S T I C LINDER EXAMINATION I S FORM S M O K E F i r c S t a r t s i n ;I S u l t c L O C A T I O N O F O C C U P A N T S [ i r i n h l c r a n d A u t o m a t i c
I'xt i n g o i hllrn~>nt (whoTc hlli I d i n g i
SnloLc. I\:! l-r' I r 1.5
1:t111t r o l of' I ' I ' C . S \ I I I ' < ,
1 ) i ! ' ~ L ~ I ' C I I V ~ ; I I s
1.i rc, K < . i i .;t:lncc
I.l:lnic Spl-cad o f I ' i ~ ! i .;I1
SIK: o f F i n i st1
K r d r ~ c t i o n o f I:i r e I.o;l(l ( ( : o n t e r l t s )
I l c d u c t i o n o f I : i r r I.uad ( i : o n . ; t r l l c t i o n )
I'rov i .; i c i l ~ o f ilr~c. 01. Mi>l.c I:gr"s? tHtllll (.L: Ar<,;l of. I K v I ' I I ~ L ~ ( ' < ~ I I ~ , L , I > I I l c - I r<.l i o n S y i t i a n l \ Alarln : ~ n d (:omnlllnicat i o n s S y s r c m s 1 ' : l c t i c a l C o n t r o l o f l i v : ~ c u a t i o n Hehay i u u r I:i r r I : ~ g h t i n y ( F i r s t Aid :111d I ' r o f c . ; . ; i o l l ; ~ l ) YI:S/NO - I.; t l i < % ~ > r i n c i l > l e o r c o m h i n n t i o n p o t c n t i o l l y s u f f i c i e n t t o ;Is.;llrc t l i ~ . s ; l f c t y o f o c c l l p a n t s o f t h c s e l e c t c d s p a c e ? c o ! . l I ' r < 1 s I h i ; - S I N G L E
-
P K T h C : I P I . i : S F i g u r e 2FORM
S M O K E
(
I ' i ~ . r S t a r t s in :I s u i t 7Y I ' S / N O - Is t h c print i p l c or ~ ' o m l > i n a t i o n p o t e n t i a l l y s u f f i c i e n t t o
HAZARD CHARACTERISTIC UNDER EXAMINATION I S F I R E FORM CASE STUDY d 1 L O C A T I O N O F O C C U P A N T P R I N C 1 P I. I-: F i r e S t a r t s i n a S u i t e S p r i n k l e r and A u t o m a t i c lixt i n g u i sllment ( w l ~ o l c h u i l d i n g ) 1:iri- harriers ) : i r e R c s i s t ; l n c e I:lame S p r e a d o f F i n i s h R e d u c t i o n o f F i r e Load ( C o n t e n t s ) R e d u c t i o n o f F i r e Load ( C o n s t r u c t i o n ) I ' r o v i s i o n o f One o r Mort l i p r e s ? R o u t e s Arr;, of Rrfllpc 1:onccl)t I l ~ . r c ~ . l ioll SystcmS Al:~rm ; ~ n d Cornmu~~ication.;~ S y s t e m s l ' a c t i c 3 1 C o n t r o l o f E v a c u n t i o n Beliavi o u r F i r e F i g h t i n g ( F i r s t Aid a n d P r o f e s s i o n a l ) YI:S/NO - 1 s t h c p r i n c i p l e o r c o m b i n a t i o n p o t e n t i a l l y s u f f i c i e n t t o ; I s s l l r r t h e w f c t y o f o c c u p a n t s o f t h e s e l e c t e d s p a c c ? d C O M P R I S I N G - S I N G L E - P R I N C I P L E S Figure 5
HAZARD C I / A R A C T E R I S ! ! I C U N D E R EXAMINATION 1.5 FORM CASL STUDY H 1 F I R E F i r e S t a r t s i n a S u i t e L O C A T I O N O F O C C U P A N T P R I N C I P L E S p r i n k l e r a n d A u t o m a t i c F x t i n g u i s h m r n t ( w h o l e b u i l d i n g 1 I ' i r c harrier> I:i r e I k s i s t o r l c c
I:I;lmc S p r e a d o f Fir1 i .;I1
R e d l r c t i o n o f F i r e Load (Con t e n t s ) R e d u c t i o n o f F i r e 1,o:ld ( C o n s t r u c t i o n ) I ' r o v i s i o n o f One o r More E g r e s s R o u t e s
AT?;] o f Rct'tljie Concept
l l r t r t . t i i ) 1 1 S y s t e m s A l i ~ r ~ n illld (:ommllnic;~l i o n s S y s t c n l s 'I';kct i c;r l ( : o n r r o l oL' . , ~ c u ; r r i o n Rehilviollr I : i r c F i g h t i n 8 ( I T i r s t Aid i ~ n d P r o f e s s i o n a l ) yes? no yes? YES/NO - Is t h e p r i n c i p l e o r c o m b i n a t i o n p o t e n t i a l l y s u f f i c i e n t t o a s s u r e t h e s a f e t y o f o c c u p a n t s o f t h e s e l e c t e d s p a c e ? S Y S ' I ' I . M S C O M I ' R I S I N G P R I N C I P L E S
2
F i g u r e 6HAZARD CHARACTERISTIC UNDER EXAMINATION I S F I R E FORM S p r i n k l e r a n d Autom;lt i c I x t i n p u i s h ~ n c n t ( w h o l e b11i i d i n g ) l : i r c h a r r ~ c r s I. i r c H e s i s r : l n c c I:lnmc S p r c a d o f F i n i s h R e d u c t i o n o f I:i r e Load ( C o n t e n t s ) R e d u c t i o n o f F i r c Load ( C o n s t r u c t i o n )
I'rovi s i o n o f Onc o r More E ~ r e s s R o u t e s
A r r o o f Rcfllpc C o n c c p t
IlcLcct i<>li Systems
A l : ~ r r : ~ illid (:omm11n i c a t i o11.; S y s t r m s
'S:lct i c a l C o n t r o l o f l i v a c u a t i o n R e h a v i o u r [ : i r e F i g h t i n g ( F i r s t Aid i ~ n d P r o f e s s i o n a l ) CASE STUDY 7 1 - - F i r e S t a r t s i n a S u i t e L O C A T I O N O F O C C U P A N T
I
-c o m m o n t o a l l
-I
S Y S T E M S C O M P R I S I N G P R I N C I P L E S OTHER BUILDINGS SII ITE YI.S/NO - I s t h e p r i n c i p l e o r c o m b i n a t i o n p o t c n t i a l l y s u f f i c i e n t t o a s s u r e t h e s a f e t y o f o c c u p a n t s o f t h e s e l e c t e d s p a c e ? F i g u r e 7 SHAFT FI.OOR ENTIRE BUILDINGI N T E N S I T Y
T H E D E G R E E OR " I N T E N S I T Y " W I T H W H I C H E A C H O F T H E M E A S U R E S I S A P P L I E D I S Q U A N T I F I E D A R B I T R A R I L Y O N A S C A L E 1 T O 1 0 .F I G U R E
8
'THE ( P R O F I L E I K E Y I M A T R I X ) O F A C O M B I N A T I O N
O F S I X M E A S U R E S W H I C H M E E T S O R E X C E E D S
T H E C H O S E N D E G R E E O F S A F E T Y
F I G U R E 9
T R A D E O F F S
- 1,B a l a n c i n g " I n t e n s i t i e s "
F I G U R E
10T R A D E O F F S
-
2, S u b s t i t u t i o n o f P r i n c i p l e s
F I G U R E
11
S Y S T E M
-
P R O P O S A L F I G U R E 1 2 G E T T I N G A P P R O V A L , A B a s i s f o r N e g o t i a t i o n s 6 P R I N C I P L E S SPR I N K1
I
P R O T E C T S - e v e r y p e r s o n P R O T E C T S - a l l b u t t h r o u g h o u t t h e b u i l d i n g . t h o s e i n f i r e s u i t e . A P O S S I B L E R A T I O N A L E F O R A S S E S S I N G S Y S T E M S W H I C H C O N T A I N P R l N C I P L E S H A V I N G A S T A T I S T I C A L C H A N C E O F F A I L U R EF I G U R E 14 F A I L U R E N I L ( S y s t e m O K ) P A R T I A L ( p a r t o r f u l l f a i l u r e o f o n e p r i n c i p l e ) M o r e s e r i o u s V e r y s e r i o u s P O L I C Y R E G A R D I N G A L L O W A B L E C O I V S E Q U E N C E S O F S T A T I S T I C A L F A I L L I R E T O P E R F O R M A S E X P E C T E D L O C A T I O N O F PERSON H A Z A R D E D F I R E S U I T E
![[DOC] Télécharger cours Base de données et sql](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==)