Environmental Engineering Reference
In-Depth Information
PART III
Geologic Hazards
Purpose and Scope
Part III sets forth the basis for recognizing, understanding, and treating the geologic haz-
ards to provide for safe and economical construction. It invokes general concepts rather
than rigorous mathematical analyses.
Significance
Geologic hazards represent substantial danger to humans and their works. The hazards may
exist as a consequence of natural events, but often they are the result of human activities.
Slope failures
, such as landslides and avalanches, can occur in almost any hilly or moun-
tainous terrain, or offshore, often with a very frequent incidence of occurrence, and can be
very destructive, at times catastrophic. The potential for failure is identifiable, and there-
fore forewarning is possible, but the actual time of occurrence is not predictable. Most
slopes can be stabilized, but under some conditions failure cannot be prevented by rea-
sonable means.
Ground subsidence, collapse
, and
expansion
usually are the result of human activities and
range from minor to major hazards, although loss of life is seldom great as a consequence.
Their potential for occurrence evaluated on the basis of geologic conditions, is for the most
part readily recognizable and they are therefore preventable or their consequences are
avoidable.
Earthquakes
represent the greatest hazard in terms of potential destruction and loss of life.
They are the most difficult hazard to assess in terms of their probability of occurrence and
magnitude as well as their vibrational characteristics, which must be known for aseismic
