Standard Shear Walls - The Analysis of Irregular Shaped Structures - page 334

F i g u r e 9.4 Typical hold-down installations.
Having to install multiple hold-downs on a shear wall chord is an indication that
too much demand is being required of the lateral-force-resisting system and its ele-
ments. A better choice would be to reevaluate the proposed lateral system and add
some redundancy, thereby reducing the demand on the shear walls.
Whenever multistory shear walls are designed, compression blocking must be installed
below the shear wall chords to prevent buckling of the framing members in the floor space
and to transfer the compression forces brought about by shear wall overturning. Figure 9.5
shows the condition at a story-to-story transfer of hold-down forces.
Failure to install hold-down anchors in accordance with the manufacturer's instruc-
tions can greatly reduce the capacity of the hold-down connection or cause localized
failures of critical shear wall members. Several common installation problems that can
cause failures can be seen in Figs. 9.6 and 9.7. A common installation error occurs at
door openings when the heads of the hold-down bolts are concealed by countersinking
the bolts into the stud, as shown in Fig. 9.4. The anchor manufacturer requires a mini-
mum thickness for a specified hold-down capacity. The countersinking can reduce the
net thickness of the multiple studs to an unacceptable thickness, thereby reducing the