Building Design and Construction Handbook - Merritt - Ventech!

SECTION THREE
PROTECTION AGAINST
HAZARDS
David W. Mock*
Gee & Jenson
West Palm Beach, Florida
A hazard poses the threat that an unwanted event, possibly a catastrophe, may occur.
Risk is the probability that the event will occur. Inasmuch as all buildings are
subject to hazards such as hurricanes, earthquakes, flood, fire, and lightning strikes,
both during and after construction, building designers and contractors have the
responsibility of estimating the risks of these hazards and the magnitudes of the
consequences should the events be realized.
3.1 RISK MANAGEMENT
After the risk of a hazard has been assessed, the building designers and contractors,
guided by building-code, design standards, zoning-code, and health-agency specifications
and exercising their best judgment, should decide on an acceptable level
for the risk. With this done, they should then select a cost-effective way of avoiding
the hazard, if possible, or protecting against it so as to reduce the risk of the hazard’s
occurring to within the acceptable level.
Studies of building failures provide information that building designers should
use to prevent similar catastrophes. Many of the lessons learned from failures have
led to establishment of safety rules in building codes. These rules, however, generally
are minimum requirements and apply to ordinary structures. Building designers,
therefore, should use judgment in applying code requirements and should
adopt more stringent design criteria where conditions dictate.
Such conditions are especially likely to exist for buildings in extreme climates
or in areas exposed to natural hazards, such as high winds, earthquakes, floods,
landslides, and lightning. Stricter criteria should also be used for buildings that are
*Revised and updated from Sec. 3, ‘‘Protection Against Hazards’’ by the late Frederick S. Merritt,
Consulting Engineer.
3.1