Discontinuous Shear Walls - The Analysis of Irregular Shaped Structures - page 419

F i g u r e 11.11 Partial shear panel layout.
prevent rotation. In addition to, and apart from, this requirement, a load path is required
to transfer the roof or floor diaphragm shears to the shear wall, collector, or diaphragm
chord below. In many cases, the framing members or blocking that is provided to prevent
rotation of the joists also functions as the mechanism to transfer lateral forces. Situations
may occur where the rotation prevention requirements are met but additional attention
is required to provide a complete load path for the transfer of the lateral forces. There
have been occasions where it was thought that by reducing the number of shear panels
required for the lateral system, considerable material costs and labor could be saved.
It is very important to resist the temptation to reduce the number of blocking panels.
Providing partial shear blocking for only portions of the wall creates a situation that is
similar to the offset shear wall examined in Example 11.2. Partial blocking places a high
demand on a limited number of panels, increasing the chance of a failure. Whenever this
approach has been used, it is often assumed that a single note placed on the drawings,
requiring the panels to be placed every other bay or every third bay, would provide the
necessary information to maintain stability of the joists and effectively transfer the shears
into the wall. This approach presumes that the contractor would frame it correctly and
that the building inspector would not detect any concerns, based solely on the plan note.
Contractors and building inspectors are typically familiar with blocking used to prevent
rotation but are not always aware of the lateral load path requirements. To successfully
address this concern, calculations are required to confirm that a complete load path
has been established. The design must be fully detailed on the drawings. Structural
observation, in addition to building department inspections, should be provided to
verify that the intent of the design has been met.