Attaching to Concrete Shear Walls

Last updated February 19, 2024
By Ian Story

When dragging a heavy collector load into the top of a concrete shear wall, concrete breakout in shear can be fairly easily prevented by adding anchor reinforcement. This leaves 2 failure modes to address: anchor bolt shear, and pryout. Anchor bolt shear is easy to increase by simply adding more anchors or increasing their diameter. But pryout is much more limiting. ACI does not appear to allow anchor reinforcement to preclude pryout, and this failure mode is independent of the type of anchor used. Therefore, the limiting capacity is determined solely by the strength and dimensions of the concrete.

Pryout Capacity

For an 8 inch thick, f’c = 2,500 psi concrete wall with centered anchor bolts, the pryout capacity is limited to 8,064 lb per foot of length. If the anchor bolt is centered in a 2×6 plate, this capacity is reduced to 7,504 lb per foot of length.