Corner angle embed plate capacity
Corner angle embed plate capacity
(OP)
Hello,
I'm an intern trying to determine the capacity of the angle shown in the attachment but I'm having trouble figuring out how to do so. PROFIS or other software that I know of don't have such embeds in their inventory so we thought of figuring out an analogous shape. The attachment shows our thinking: I think the failure plane would be like that based off ACI, and so I could maybe use a square plate with a width equal to the width of the failure plane and the embed depth shown. However I don't know what edge distance I would use.
Would anybody be able to help me validate my method or show me another way of doing this? Thank you.
I'm an intern trying to determine the capacity of the angle shown in the attachment but I'm having trouble figuring out how to do so. PROFIS or other software that I know of don't have such embeds in their inventory so we thought of figuring out an analogous shape. The attachment shows our thinking: I think the failure plane would be like that based off ACI, and so I could maybe use a square plate with a width equal to the width of the failure plane and the embed depth shown. However I don't know what edge distance I would use.
Would anybody be able to help me validate my method or show me another way of doing this? Thank you.






RE: Corner angle embed plate capacity
I have to say, however, that your proposal actually sounds like a pretty reasonable lower bound capacity method. It's clever. The concrete checks will have to include shear, tension, and moment on your hypothetical failure plane however. I don't have high hopes for the capacity.
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: Corner angle embed plate capacity
Follow-up question: do you think my drawing is an accurate representation of the internal shear and tension? I'm not sure where the moment would come from though
RE: Corner angle embed plate capacity
As far as getting a number, ACI 318-14 chapter 17 does include cast-in-place anchors. You should be able to apply the method for an edge directly since the angle does not change the tension characteristics of the concrete. Obviously you would use the distance to the edge of concrete where is is formed by the angle.
RE: Corner angle embed plate capacity
I do think it an accurate representation. If I were doing this, I would assume that:
a) all of the vertical load is applied at the angle end of the studs and;
b) there is no concrete between the angle and your blue failure plane.
If you look at it this way, I think that you'll see the moment on the stud and the concrete breakout cone. Is this a conservative assumption? You bet -- that ignored concrete will help. However, without considering this moment in some fashion, I feel that your proposal fails to take into account a prying action that I will be present on the concrete breakout cone.
Have you checked the PCI manual for guidance on this? I don't know if they have anything but, if anybody does, I suspect it would be PCI.
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: Corner angle embed plate capacity
TXStructural, thank you as well for the response. I'll discuss the drawbacks of this connection with the engineer I'm working with. We're actually checking a head-knocker issue with the stairs but thought we'd look at this as well since it's part of the load path and it struck us as unusual. I'll check the section in ACI you referenced as well and if we don't find the capacity we need or even if we do, we may talk with the original EOR about this connection.