Base Plate Anchor Rod Hole Size
Base Plate Anchor Rod Hole Size
(OP)
Sorry I missed Subject in my previous post.
I designed cooling tower structure (per UBC'97, Seizmic Zone III) and provided foundation load w/ base plate detail to the customer who will design foundation. I specified standard oversized 1 3/4" hole for 1 1/4" anchor rod and customer asked why 1/2" oversize - their concern is shear transfer. Please advice.
I designed cooling tower structure (per UBC'97, Seizmic Zone III) and provided foundation load w/ base plate detail to the customer who will design foundation. I specified standard oversized 1 3/4" hole for 1 1/4" anchor rod and customer asked why 1/2" oversize - their concern is shear transfer. Please advice.






RE: Base Plate Anchor Rod Hole Size
AISC also states in J1.11 all of the limitations on Bolted Connections - and at the end, states that "In all other cases connections are permitted to be made with A307 bolts or snug-tight high strength bolts."
No commentary in Chapter 14 or in the spec (that I can find) appears to concern itself with the oversized holes. I have seen, in high seismic areas, where the base plate had a key plate set down in a slot in the concrete between the projecting anchors to take shear.
RE: Base Plate Anchor Rod Hole Size
RE: Base Plate Anchor Rod Hole Size
Shear may be transfered thru the anchor bolts if a plate washer (with 1/16" oversized hole)is field welded to the base plate at each anchor bolt. Another way to transfer shear is with a shear lug welded to the bottom of the base plate.
RE: Base Plate Anchor Rod Hole Size
If you have normal column, consider using adhesive anchors. You can have the bolthole size 1/16 or 1/8 of an inch larger than the AD diameter.
Good luck.
RE: Base Plate Anchor Rod Hole Size
RE: Base Plate Anchor Rod Hole Size