column bas shims

[adn007]

We are putting up a 4 story building, simple framing. W8x67 is the largest col member size. Some of the piers are 1"1/2 too low. Can the columns be shimmed to compensate for this elevation change?

If we can shim up to 1"1/2 should the shims be comb type and welded together so as not to slip?

 

[jike]

First option is if the columns are not fabricated yet, have them cut longer. Or raise all the holes and lower the column splice and lengthen the 2nd lift of columns.

Atre these all gravity columns? Any uplift or shear?

Shims welded together may be an option. Do you even need shims? Are the anchor bolts long enough?

Just extend the grout pad. Depending on its thickness, you may have to mix in pea gravel.

 

[lkjh345]

IMHO: I would first check out just extending the grout pad. If you had orginally planned on say 1 1/2" of grout, a 3" grout pad (with pea gravel as jike suggests) does not seem unreasonable.

Are the anchor bolts taking any shear or tension? Do they have enough current projection to get nuts on (not likely, but you never know), or can they be extended with threaded couplers?

FWIW, I had a call last week saying that a whole row of footings on one of my buildings was cast 5" too low. Unfortunately, a lot of these columns were part of a braced framed system. Such is the way it goes sometimes.

 

[hokie66]

I suggest adding a 1 1/2" plate. If no shear on base, make plate same size as column base plate. If shear exists, make plate slightly larger to allow welding two plates together. Better solution than so much grout, still depends on the anchor bolts being long enough. If the anchor bolts do project enough, check that they are embedded enough.

 

[J1D]

adn007, if the projection is not enough, how about bore the original holes (on the base plate for anchor bolts)larger and weld a new 1.5" thick base plate on (at the borehore locations as well) ?