1.1 Clear width (Wc
)
Clear width is measured off the handrail(s) for corridors and stairways and
the actual passage width of a door in its fully open position.
1.2 Initial density of persons (D)
The initial density of persons in an escape route is the number of persons
(p) divided by the available escape route area pertinent to the space where the persons
are originally located and expressed in (p/m2).
1.3 Speed of persons (S)
The speed (m/s) of persons along the escape route depends on the specific
flow of persons (as defined in 1.4) and on the type of escape facility. People speed
values are given in tables 1.1 (initial speed) and 1.3 below (speed after transition
point as a function of specific flow).
1.4 Specific flow of persons (Fs
)
Specific flow (p/(ms)) is the number of escaping persons past a point in
the escape route per unit time per unit of clear width Wc
of the route involved. Values of FS
are given, in table 1.1 (initial FS
as a function of initial density) and in table 1.2 (maximum value) below.
Table 1.1 Values of initial
specific flow and initial speed as a function of density
footnote
|
Type of facility
|
Initial density D (p/m2)
|
Initial specific flow FS
(p/(ms))
|
Initial speed of persons S (m/s)
|
| Corridors
|
0
|
0
|
1.2
|
| 0.5
|
0.65
|
1.2
|
| 1,9
|
1.3
|
0.67
|
| 3.2
|
0.65
|
0.20
|
| ≥ 3.5
|
0.32
|
0.10
|
Table 1.2 Value of maximum
specific flow
footnote
|
Type of facility
|
Maximum specific flow
FS
(p/(ms))
|
|
Stairs (down)
|
1.1
|
|
Stairs (up)
|
0.88
|
|
Corridors
|
1.3
|
|
Doorways
|
1.3
|
Table 1.3 Values of specific flow
and speed
footnote
|
Type of facility
|
Specific flow Fs (p/(ms))
|
Speed of persons S (m/s)
|
|
Stairs (down)
|
0
|
1.0
|
| 0.54
|
1.0
|
| 1.1
|
0.55
|
|
Stairs (up)
|
0
|
0.8
|
| 0.43
|
0.8
|
| 0.88
|
0.44
|
|
Corridors
|
0
|
1.2
|
| 0.65
|
1.2
|
| 1.3
|
0.67
|
1.5 Calculated flow of persons (Fc
)
The calculated flow of persons (p/s) is the predicted number of persons
passing a particular point in an escape route per unit time. It is obtained from:
1.6 Flow time (tF
)
Flow time (s) is the total time needed for N persons to move past a
point in the egress system, and is calculated as:
1.7 Transitions
Transitions are those points in the egress system where the type (e.g., from
a corridor to a stairway) or dimension of a route changes or where routes merge or
ramify. In a transition, the sum of all the outlet-calculated flow is equal to the sum
of all the inlet-calculated flow:
|
Σ Fc(in)i
|
= |
Σ Fc(out)j
(1.7) |
where:
|
Fc
(in)i
|
= |
calculated flow of route (i) arriving at transition point |
|
Fc
(out)j
|
= |
calculated flow of route (j) departing from transition point |
1.8 Travel time T, correction factor and counterflow
correction factor
Travel time T expressed in seconds as given by:
where:
|
γ |
= |
is the correction factor to be taken equal to 2 for cases 1 and 2 and
1.3 for cases 3 and 4; |
|
δ
|
= |
is the counterflow correction factor to be taken equal to 0.3;
and |
|
tI
|
= |
is the highest travel time expressed in seconds in ideal conditions
resulting from application of the calculation procedure outlined in paragraph 2 of
this appendix. |