Table 8-1
Glazing Protection Levels Based on Fragment Impact Locations
Performance
Protection
Hazard
Condition
Level
Level
Description of Window Glazing Response
1
Safe
None
Glazing does not break. No visible damage to glazing or frame.
2
Very High
None
Glazing cracks but is retained by the frame. Dusting or very small
fragments near sill or on floor acceptable.
3a
High
Very Low
Glazing cracks. Fragments enter space and land on floor
no further than 3.3 ft. from the window.
3b
High
Low
Glazing cracks. Fragments enter space and land on floor
no further than 10 ft. from the window.
4
Medium
Medium
Glazing cracks. Fragments enter space and land on floor and
impact a vertical witness panel at a distance of no more than 10 ft.
from the window at a height no greater than 2 ft. above the floor.
5
Low
High
Glazing cracks and window system fails catastrophically.
Fragments enter space impacting a vertical witness panel at a
distance of no more than 10 ft. from the window at a height
greater than 2 ft. above the floor.
* In conditions 2, 3a, 3b, 4 and 5, glazing fragments may be thrown to the outside of the protected space toward the detonation location.
The designer of the window systems may use the outputs
Design up to specified load. Window systems for the
from government produced and sponsored computer
exterior faade should be designed to be in balance with
programs (e.g., WINGARD, WINLAC, SAFEVUE)
the framing, anchorage and supporting walls in order to
coupled with test data and recognized structural dynamic
mitigate hazard of flying glass in an explosive event. The
analysis procedures to show that the glazing either
walls, anchorage of the window to the walls or floors, and
survives the specified threats or the post damage perfor-
the window framing itself should be designed for the
mance of the glazing protects the occupants in accordance
maximum capacity of the glass type selected. This is to
with the conditions specified here (Table 8-1). When
ensure that the glass fails before the window frame or wall
using such methods, the designer may consider a breakage
can fail.
245
SECURITY
DESIGN
8.4
New Construction
Revised March 2005 PBS-P100
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