Standard Shear Walls - The Analysis of Irregular Shaped Structures - page 335

F i g u r e 9.5 Typical hold-down installations.
capacity of the anchor. An additional stud should be installed to account for the coun-
tersinking. Another common installation error occurs when the hold-down anchor bolt
is misplaced in the foundation. Figure 9.6 shows two conditions where the anchor bolts
have been misplaced. The detail on the left side of the figure shows the condition where
the hold-down anchor is installed with an in-plane offset. The contractor will usually
attempt to bend the anchor bolt extension to enable connection to the hold-down. The
detail on the right side of the figure shows the condition where the anchor bolt is
installed horizontally offset (out of plane) from the centerline of the stud. Whenever a
tension force is applied to either of these connections, the hold-down tries to straighten
out, causing cross-grain tension to occur at the bolted connection or localized bending
in the boundary member. Failure to tie the anchor bolt in place properly or stabbing it
into the wet concrete can also cause voids in the concrete around the bolt, severely
reducing the capacity or rendering it ineffective. If the anchor bolt is placed too close to
the edge or end of the foundation wall, an inadequate edge/end distance can cause
spalling of the concrete or cause a reduced capacity of the anchor. Figure 9.7 shows a
strap anchor installation at the foundation wall. Common installation problems occur
when the anchor is misplaced or purposely bent over to accommodate the installation
of the wall framing.