No of Anchor Bolt Carrying Shear
ns = number of anchor bolt engaged in shear force
        transfer from base plate to anchor rods

Set n = total anchor bolt number in the bolt group

Due to the oversized holes on column base plate, only
0.5 x n
number of bolt shall be considered for shear
force transfer through bearing, unless the anchor bolt
washers are tack welded to base plate. (Reference:
AISC Design Guide 1 Base Plate and Anchor Rod Design
2nd Ed - Section 3.5.3)

Set ns = 0.5 x n if no provisions are made to equalize
             the shear force transfer from base plate to all
             anchor rods

Set ns = 1.0 x n if plate washers are welded to base
              plate and anchor rod nut

AISC Design Guide 1 Base Plate and Anchor Rod Design
2nd Ed Section 3.5.3