facilities where severe damage is unacceptable, and
persons licensed in the appropriate disciplines, and
also for noncritical facilities where a long-term user
experience in seismic analysis, including the theory
is willing to accept the higher initial coats in
and application of energy-dissipation methods. The
exchange for reduced future damage costs.
design review should include, but should not
necessarily be limited to, the following:
(1) Conventional design using elastic design.
Using conventional design, earthquake damage can
Preliminary design including sizing of the
generally be prevented only by designing for higher
devices;
and higher seismic forces.
Critical facilities built
using conventional design may need to be designed
Prototype testing;
to remain elastic even for major earthquakes. The
resulting design forces must be resisted elastically by
Final design of the rehabilitated building and
all of the critical structural and nonstructural building
supporting analyses; and
components. Such design procedures result in larger
structural members and more costly construction than
Manufacturing quality control program for
life-safety design procedures, and are rarely used
the energy-dissipation devices.
except for facilities such as nuclear power plants.
i.
Required Tests of Energy Dissipation
(2) Seismic isolation and energy dissipation.
Devices. Required testing, and peer review of the
Facilities that incorporate seismic isolation and
testing, to establish and validate the design properties
energy dissipation systems can be designed to take
of the energy-dissipation devices, shall be similar to
advantage of the dynamic characteristics and the
that required by Section 13.9 and the appendix to
nonlinearities inherent in these systems to reduce the
Chapter 13 of FEMA 302.
seismic accelerations and displacements.
Thus,
critical structural and nonstructural components may
generally be designed using substantially lower
8-5.
Guidance for Selection and Use of Seismic
element forces than would be required using elastic
Isolation and Energy Dissipation Systems.
design procedures to achieve the same level of
a.
Earthquake Damage Mitigation. Earthquake
earthquake protection.
damage to nearly any structure could be reduced
through the judicious use of some type of seismic
b.
Type of Facility. Important, essential, and
isolation or energy-dissipation system. Although the
historic facilities may be good candidates for seismic
initial design and construction costs for these systems
isolation
or
energy-dissipation
systems,
since
may be higher than for conventional design, current
earthquake damage to such facilities may have costly
data suggest that they will pay for themselves over
and unacceptable consequences. Examples of such
the life of a structure in reduced earthquake damage.
consequences might include a major hazardous
These systems might be appropriate for critical
materials release from a facility located in an urban
8 - 38
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