PCI Design Handbook Help

[EITInWI]

New to column and found this older post in research and looking for help. I am wondering if any of you know how to analyze the angle support given in the thread linked below.

Link

I am looking to design a new steel angle as a seat angle connection into an existing concrete beam to support form work for a concrete slab deck. The depth of the beam limits the design to be Option #1 in the attachment. My company has a designed spreadsheet for Option #2 to determine the tension on the anchor bolt, as well as the bending on the horizontal leg of the angle using the Flexible Method from PCI Design Handbook Precast and Precast Concrete, Sixth Ed. I am struggling with how to analyze the connection because there seems to be too many variables to solve for in the applied loading. Option #1 will not apply to Option #2 because instead of the vertical flange at the wall being in compression at the bottom, it will be moving away from the wall at the top of the vertical flange, and the bottom of the angle will be in compression. Also notice PCI accounts for a axial load Nu at the horizontal flange. Any help is appreciated, thanks.

I have attached a helpful picture that was included in the linked post and I have added my FBD in the same document.

 

[KootK]

Are you bolting or welding the angle in place? Usually, this case is easier than with the vertical leg down as prying is much less of an issue. I'd be inclined to ignore Nu for formwork support. If a serious Nu for develops, the formwork will probably just slip off of the angle.

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.

 

[EITInWI]

Thanks for the help. As a follow-up, after I posted this yesterday I downloaded a file off the SteelTools website which ignored the Nu force, as you recommended. It would increase the tension in the bolt, but I am no longer worried about this, since PCI recommends to assume 0.2*Vu (or 20% of the vertical load on the horizontal flange). This would be a very insignificant load, even when applying the 1.33 Over Load Factor. I analyzed the angle taking the most and least conservative results by selecting whether to include the thickness of the angle or not in the calculation of the moment.

The difference is 42% > 27% -->(0.2*1.333) for my case. I attached a summary of my findings.

Thanks for the help KootK

 

[KootK]

You're most welcome. I feel that including the thickness of the vertical angle legs is the right choice here.

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.