(2) Damage caused by seismic displacements.
area, major equipment malfunction at a regional
Seismic displacements may also damage building
emergency response center, or the destruction of an
components. Nonstructural components attached to
irreplaceable historic structure.
Such events are
unacceptable, particularly when techniques are
particularly vulnerable to displacement damage.
available to prevent them.
Seismic isolation or
Light items that are unlikely to generate large inertial
forces may still be damaged by large imposed
the design of critical facilities to prevent these types
Nonstructural components such as
of disasters from occurring.
glazing, precast cladding, rigid full-height partitions,
Earthquake Effects - Acceleration vs.
sprinkler piping, hazardous material piping, and
exterior veneer or ornamentation may be damaged by
Building components may be
large interstory drifts caused by the seismic
damaged by both seismic accelerations and seismic
displacements of the building frame. Items that cross
A particular type of component,
seismic joints between adjacent buildings are also
either structural or nonstructural, may be more
vulnerable to displacement damage.
sensitive to one or other type of damage. In order to
reduce earthquake damage, it is important to consider
(3) Damage identification. It is important to
whether critical building components are vulnerable
identity what critical building components are
to acceleration damage, displacement damage, or
vulnerable to damage, what type of damage they are
vulnerable to, and what level of damage protection is
desired for critical components of a given facility in
(1) Damage caused by seismic accelerations.
techniques. In some cases, acceleration control may
be required in order to reduce potential acceleration
components, and piping or sensitive equipment. A
damage. In other cases, displacement control may be
building component may be damaged when the
and displacement control may he required to provide
component exceed the elastic capacity of the
effective damage reduction.
component to resist those forces. Some examples of
damage due to excessive inertial forces caused by
System Selection - conventional design,
seismic accelerations include the following: shear
cracking in a masonry shear wall; out-of-plane failure
selection of a structural system for a critical facility is
of a freestanding wall or heavy partition; shear failure
a complex process that must take many factors into
of anchor bolts at the base of a piece of heavy
These factors include the dynamic
equipment; and pipe rupture at an anchor point for a
characteristics of the building, the surrounding soil,
long, unbraced section of heavy pipe.
and the critical nonstructural components.
present construction costs and future damage costs
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