Extend Footer To Accommodate Anchor Bolt Edge Distance
Extend Footer To Accommodate Anchor Bolt Edge Distance
(OP)
So things didn't go as planned on this project. Somehow the location of a large concrete footer was set incorrectly. Instead of moving the footer or re-pouring it the contractor and steel erector opted to cut the anchor bolts and epoxy in new ones. The columns eccentricity on the footer is 7" in the x direction and 5" in the y direction.
The problem I am running into is the anchor bolts that were epoxied in are coming up short on tension capacity. The reason they are insufficient is because I only have a 6" edge distance for a 1" dia threaded rod. Has anyone ever extended a footer to increase an anchor bolt edge distance? I was thinking that we could extend the footer by 12" with some Quikrete bonding adhesive and pinned reinforcing. I don't need to extend the footer for bearing capacity. The extension would be purely to increase my anchor bolt edge distance.
The problem I am running into is the anchor bolts that were epoxied in are coming up short on tension capacity. The reason they are insufficient is because I only have a 6" edge distance for a 1" dia threaded rod. Has anyone ever extended a footer to increase an anchor bolt edge distance? I was thinking that we could extend the footer by 12" with some Quikrete bonding adhesive and pinned reinforcing. I don't need to extend the footer for bearing capacity. The extension would be purely to increase my anchor bolt edge distance.






RE: Extend Footer To Accommodate Anchor Bolt Edge Distance
Dave
Thaidavid
RE: Extend Footer To Accommodate Anchor Bolt Edge Distance
Just how big is this large footing?
Any chance you could design an eccentric base connection for which new post installed anchors would have sufficient edge distances?
Of the non-repour options available, extending the concrete is probably a good choice. Remember though, once you extend the footing, some of the bolt tension will then live out in that extension. That may mean that the extension will need to be anchored to bring that force back to the main body of the footing.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Extend Footer To Accommodate Anchor Bolt Edge Distance
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Extend Footer To Accommodate Anchor Bolt Edge Distance
This should help the breakout strength. Much simpler than adding concrete.
RE: Extend Footer To Accommodate Anchor Bolt Edge Distance
RE: Extend Footer To Accommodate Anchor Bolt Edge Distance
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Extend Footer To Accommodate Anchor Bolt Edge Distance
RE: Extend Footer To Accommodate Anchor Bolt Edge Distance
The footing is 4'-0" x 8'-6" x 24" thick. I've been using Hilti's design tables so I am not sure what is controlling the design. My suspicion is concrete breakout capacity is insufficient due to the limited edge distance. I don't think the breakout cone is large enough with the limited edge distance. I'm going to run the calcs by hand later today to find out what's controlling. An eccentric base plate is a good idea however everything is installed already so the original anchor bolts have been cut.
It is an important moment connection. I think total replacement of the existing footing may be the way to go.
RE: Extend Footer To Accommodate Anchor Bolt Edge Distance