Glazing and windows
|Costs of strengthen
Typical causes of damages
Windows and partitions are usually damaged because of the structural drift imposed upon these vertically oriented, rigidly built-in non-structural items.
Use of tempered glass will greatly reduce the seismic hazard. Tempered glass may still break, but will break into small dull fragments instead of large dangerous shards.
Polyester shatter resistant films (safety and security window films) help hold together fragments of any panes of glass in order to avoid injuries from flying glass. Typical solar film may not be adequate for this purpose.
Use of laminated glass for storefronts reduces seismic risk and also increases protection from vandalism. Blinds or even curtains can offer additional protection from shards of glass.Stiffening bracing or redesigning of the window frame can reduce earthquake damage from window frame distortion and inadequate edge clearance around the glass.
(Source: 3MTM Safety & Security Window Films)
Bracing usually consists of steel tie rods anchored to the corners of the window frame and connected by a turnbuckle (Figure, left side). Another method is to use specially designed windows that use wider frames and include a compressible material between the frame and the window glass to avoid direct contact between the window and the frame (Figure, right side).
(Source: FEMA, 2004) http://www.un-spider.org/sites/default/files/6-Earthquake_Mitigation_FEMA.pdf