Foundations - Chapter 9.
(e)
For some components it is
convenient to prescribe acceptance criteria in terms
Nonstructural Systems and Components
of deformation (e.g., 2 or )), while for others it is
more convenient to give criteria in terms of
Chapter 10.
deformation ratios. To accommodate this, two types
of idealized force versus deformation curves are used
Acceptance criteria for elements and components for
in this procedure as illustrated in Figures 6-2a and 6-
which criteria are not presented in this document
Figure 6-2a shows normalized force (Q/QCE)
2b.
shall be determined by an approved qualification-
versus deformation (or )) and the parameters a, b,
testing program.
and c. Figure 6-2b shows normalized force (Q/QCE)
versus deformation ratio (2/2y, )/)y or )/h) and the
Pseudo-lateral load, V, in a given
(2)
parameters d, e, and c. Elastic stiffness and values
horizontal direction of a building, is given by
for the parameters a, b, c, d, and e that can be used
Equation 6-1. This load shall be used for the design
for modeling components for various structural
of the vertical seismic framing system when the
systems are given in Chapter 7.
Figure 6-2c
linear elastic analysis procedures are used with the m
graphically shows the approximate deformation or
values.
deformation ratio, in relation to the idealized force
versus deformation curve, that is deemed acceptable
V = C1 C2 C3 Sa W
(6-1)
in this procedure for structural components for
Immediate Occupancy (IO), Safe Egress (SE), and
where:
Life Safety (LS), Performance Levels. The Collapse
V = pseudo-lateral load. This force, when
Prevention (CP) performance level indicated in
distributed over the height of the linearly elastic
Figure 6-2c is not an acceptable performance level,
model of the building, is intended to produce
and is indicated here and in the acceptance criteria
calculated lateral displacements approximately equal
tables in Chapter 7 as a limit state for ductile
to those that are expected in the real structure during
response.
Numerical values of the acceptable
the design event. If it is expected that the actual
deformations or deformation ratios are given in
structure will yield during the design event, the force
Chapter 7 for components and elements in various
given by Equation 6-1 may be significantly larger
structural systems.
Additional guidelines on the
than the actual strength of the structure to resist that
calculation of individual component force and
force.
The acceptance criteria in the following
deformation capacities may be found in the following
paragraph are developed to take this aspect into
chapters.
account.
Base
isolation
systems
and
energy
C1, C2, C3, and Sa are defined in Paragraph
dissipation systems - Chapter 8.
5-4f(2).
6-6
Previous Page
