Horizontally Offset Shear Walls - The Analysis of Irregular Shaped Structures - page 459

F i g u r e 12.15 Typical apartment longitudinal wall layouts.
There are five basic wall configurations for placement of the transverse shear walls.
The most common arrangement is layout 1 in Fig. 12.16. The shear walls in this case are
in alignment and are connected across the corridor by a collector. This condition allows
the shear wall lines to be spaced farther apart. In layout 2, the walls are staggered, and
only one wall is used because there is no wall directly across the corridor. A roof or floor
joist is used as the collector which must extend across the full depth of the diaphragm
and connect to the shear wall. The collectors and their connections shown in the typical
detail must be designed for tension and compression forces. Whenever the collector
force becomes too large, layout 3 can be used to split the loads and distribute them into
two adjacent members. Their force must be transferred across the offset to the shear
wall. A floor framing member does not always line up with the shear wall. In that event,
layout 4 can be used. The first joist adjacent to the shear wall can be used as the collector
element. The collector must extend across the full depth of the diaphragm and lap with
the shear wall. The shear force from the collector must be transferred across the offset
into the shear wall, which causes an eccentricity. Framing members and connections
must be provided to counteract the eccentric force couple.
There have been occasions where collectors at transverse shear walls were not
installed. The rationale behind this approach is the assumption that by using every
transverse wall, the diaphragm forces are reduced to a level where collectors and chords