TABLE OF CONTENTS Shearwalls comprise the vertical elements in the lateral-force-resisting system (LFRS). They support the horizontal diaphragm and transfer the lateral forces down into the foundation. The procedures for calculating the forces to the shearwalls are covered in Chaps. 3 and 9.
Wood horizontal diaphragms are often used in buildings with masonry or concrete shearwalls as well as buildings with wood-frame shearwalls. However, the design of masonry and concrete shearwalls is beyond the scope of this book, and this chapter deals with the design of wood-frame shearwalls only.
A number of sheathing materials can be used to develop shearwall action in a wood-frame wall. These include
Wood structural panels (e.g., plywood and OSB)
Gypsum wallboard (drywall)
Interior and exterior plaster (stucco)
Fiberboard (including fiber-cement panels)
Lumber sheathing (diagonal, or horizontal sheathing with diagonal bracing)
There may be other acceptable materials, but these are representative. When the design forces (wall shears) are relatively small, the normal wall covering material may be adequate to develop shearwall action. However, when the unit shears become large, it is necessary to design special sheathing and nailing to develop the required capacity. Wood structural panels provide greater shearwall capacity than the other sheathing types listed above.
Essentially a shearwall cantilevers from the foundation and is subjected to one or more lateral forces. See Example 10.1. As the name implies, the basic form of resistance is that of a shear element (Fig. 3.5c). The concept of shear...
