RE: Shear in anchor bolts
I have used shear lugs for large shear forces but try to avoid them for
smaller shear forces due to the added cost of forming the slots in the
concrete for the shear lugs, welding the shear the shear lugs to the base
plate, and greater difficulty in grouting a base plate with shear lugs. My
definition of "large shear forces" is whatever is greater than my standard
anchor bolts can handle.
I have seen the method of using welded plate washers although I haven't used
this method much. One concern I have with this method is that the shear
is shifted higher up the anchor bolt, above the base plate - this tends to
increase bending in the anchor bolt. Also I tend to prefer to avoid the
welding of the washer plates.
I use the shear-friction method to design anchor bolts in shear, as per
to the Design of Anchor Bolts and Other Steel Embedments" (Cannon, Godfrey,
and Moreadith) as based on ACI 349, Appendix B.