recommended practice, it is assumed that the
Design Criteria. Architectural elements
partitions can withstand the design in-plane drift of
must safely resist horizontal forces prescribed by
.005 times the story height (i.e., 1/16 inch per foot
Equation 10-1, and must be capable of conforming
(5.2mm per meter) of height) without damage.
(accommodating) to the lateral deflections that they
Therefore, if the structure is designed to control drift
will be subjected to during the lateral deformations
within the prescribed limits, these partitions do not
of the structure.
require special isolation details.
They will be
designed for the prescribed seismic force acting
(1) Lateral force coefficients. Coefficients for
normal to flat surfaces; however, wind or the usual 5
pounds per square foot partition load will usually
components are provided in Table 10-1.
If the structural design drift is not
controlled within the prescribed limits, isolation of
(2) Displacements. Allowable story drift for
structures is prescribed in Table 6-1. Determination
of relative displacement applicable to architectural
between potential damage and costs of isolation will
components is prescribed in Section 6.1.4 of FEMA
be considered. A decision has to be made for each
project as to the role, if any, such partitions will
contribute to damping and response of the structure,
and the effect of seismic forces parallel to the
partition resulting from the structural system as a
(1) Partitions. Partitions are classified into
whole. Usually it may be assumed that this type of
two general categories: rigid and nonrigid.
partition is subject to future alterations in layout
location. The structural role of partitions may be
controlled by height of partitions and method of
generally refers to nonstructural masonry walls.
Walls will be isolated where they are unable to resist
in-plane lateral forces to which they are subjected,
(2) Veneered walls. There are two methods
based on relative rigidities.
Typical details for
for attaching veneer to a backup structural wall (see
isolation of these walls are shown in Figure 10-1.
These walls will be designed for the prescribed
forces normal to their plane.
(a) Anchored veneer is a masonry facing
mechanical tie attached to the backup. All required
generally refers to nonstructural partitions such as
load-carrying capacity (both vertical and lateral) will
stud and drywall, stud and plaster, and movable
be provided by the structural backup wall.
partitions. When constructed according to standard
veneer will be nonbearing and isolated on three