Structural Engineering: Re: Anchor rods set too low (again!)

This is one option we are looking at. The base plate is 1 1/2" thick. We would cut the corners from the base plates and add couplers. Then we would add another 1 1/2" (?) plate with holes large enough for the coupler. We would use standard pipe with a heavy plate washer on top extending up from the added plate with the nut on top. There may be a simpler way to do this. We're not sure if you can burn away 1 1/2" without really wrecking the anchor rod or W14 column. There is about 2 inches between the hole and the flange of the W14.

I have come across the Canam Elocone product that has a narrow lower section that fits inside the hole. It looks promising, but I am awaiting information from the contractor on the clearance and rod projection.

Dilip Patel wrote:

How about cutting the base plate & then connect designed angle with weld to column & anchor bolt projection. They can remove grout also since the column is set to
get added length for weld capacity.

Dilip Patel, PE

From: Joe Goldbronn <jgoldbronn@barrish.com>
To: seaint@seaint.org
Sent: Tuesday, June 23, 2009 2:51:15 PM
Subject: RE: Anchor rods set too low (again!)

This exact question was just submitted in the "steel interchange" section of the June 2009 issue of Modern Steel Construction, you can view the magazine for free on their website. The answer to the question was that it is an all or nothing situation, you do not get reduced capacities for reduced engagement to the nut.

Joe Goldbronn, PE

From: Drew Morris [mailto:dmorris@bbfm.com]
Sent: Tuesday, June 23, 2009 10:16 AM
To: SEAINT
Subject: Anchor rods set too low (again!)

I have a case where the anchor rods have been set too low (again). They are F1554-36 1 1/4" diameter. To make things worse, the columns have fixed bases and have been installed with the grout below the base plate installed. I'm not sure why the contractor even bothered to call this in this late.

Typically, if the rod head is flush with the top of the nut, we use the full strength of the rod. Is there a way to determine what the connection strength is between the nut and the rod if less than the entire rod is engaged? I can't enlarge the holes in the baseplate for couplers without affecting the anchor rods and I am leery of welding on an extension of the threaded rod.