Post Installed Epoxy Anchors Installed on an Angle?

[Grant M]

Hi everyone,

For a project I am working on, there are a few skids which hold compressors and blowers and are located indoors. The anchorage system specified were post-installed epoxy anchors.

The contractor is having some issues getting these installed, however, as the top flange on the skids is preventing him from drilling at a 90-degree angle from the horizontal. We also cannot drill through the top flange as equipment on the skid is interfering with that. He estimates that he would be drilling on a 10 to 15 degree angle to get the anchors in.

I haven't been able to find any code requirements with regards to epoxy anchors being installed on an angle and what effect that would have on the anchorage. Does anyone happen to know of anything that would prohibit this or of anything else I should check if we do go this route?

Thanks!

 

[KootK]

1) I assume that we're talking 10-15 degrees from the vertical. If it's from the horizontal, that's another matter.

2) I feel as though plenty of anchors that get installed in normal conditions wind up being ten to fifteen degrees off.

3) The technical reps that work for the anchor manufacturers are usually a fantastic help with this kind of thing. I recommend taking this up with them directly.

 

[strucbells]

We allow up to a 10 degree slant in our typical spec.

You could break down your resultant anchor forces into their tension and shear components with your anchor at an angle and analyze it that way. It might get a little tricky with your concrete failure modes and how those would need to be modified. I'd take a conservative approach.

The various epoxy anchor manufacturers may have some specific guidance on this as well if you don't have enough healthy margin to feel comfortable with that.

 

[Grant M]

Yes, sorry for lack of clarification, 10-15 degrees from the vertical.

Thank you for the insight, I will reach out to Hilti and see what they suggest.

 

[JedClampett]

I don't work for Hilti, but I can tell you their help desk is always knowledgeable and helpful. I've called them for that very problem (skewed anchors) and they answered quickly.