Friction and Shear Lug in Base Plates
Friction and Shear Lug in Base Plates
(OP)
I have got a question about making use of friction in the design of shear lug, or shear key, for base plates. AISC allows the use of friction, with a coeff. of 0.55 between steel and grout. However, I talked with my colleagues and most of them do not make use of friction to reduce their shear. Their reasoning is that the base plate may not be set right so friction is not developed, or that the anchor bolts are anchored in a way that does not develop friction fully. I would like to make use of friction to reduce my shear load. Who is correct? Please share your thoughts and why. Thanks in advance.






RE: Friction and Shear Lug in Base Plates
RE: Friction and Shear Lug in Base Plates
I've just been out to too many sites where the column bases were buried in mud before they grouted them....and just makes me wary that nothing gets cleaned properly or installed correctly.
RE: Friction and Shear Lug in Base Plates
RE: Friction and Shear Lug in Base Plates
In normal conditions I am with Atomic25 and UcfSE, do not use it. If you need shear resistance, have you considered a shear key?
RE: Friction and Shear Lug in Base Plates
Oh BTW, kelowna, I am using a shear key (AISC calls it shear lug) for my base plate where they are significant lateral loads. I was just hoping that I could reduce my column base shear load by deducting that portion of it that the friction would take care of. From your responses so far, that might not be viable unless I am really strict and lay down some specific notes to make sure the grouting and base plate get done right.
RE: Friction and Shear Lug in Base Plates
RE: Friction and Shear Lug in Base Plates
RE: Friction and Shear Lug in Base Plates
RE: Friction and Shear Lug in Base Plates
do you typically weld the plate washers to the baseplate in the cases where you use the anchor rods for shear resistance to make sure you get a good load path for the shear through the anchor rods since the hole in the base plate are VERY oversized?
RE: Friction and Shear Lug in Base Plates
RE: Friction and Shear Lug in Base Plates