Does anyone know if RAM-SS takes into account section 12.4.4 of ASCE 7-05 for cantilever members? If it is not taken into account by default, what would be the easiest way to check the beams for this? I suppose I could create a load combination in RAM Frame, but unless I'm mistaken, RAM Frame only looks at lateral members.
For those of you who don't have the ASCE 7-05 handy, this special seismic provision basically says that cantilever beams should be designed for a minimum net upward force of 0.2 times the dead load.
We don't automate this in RAM SS right now. We do pattern load live loads to consider live load on just the back-span, just the cantilever (or both) to produce an envelope of the worst effects, see our Ram Beam FAQ for more. But if you wanted to check this clause by the books you would have to apply an upward acting dead load that more than counteracted the rest of the dead loads manually. Using that approach you could still check the beam in the beam module without having to make the beam lateral.
Yes, thanks for clarifying the code section, Seth. And thank you for speaking to RAM's capabilities in this area.
The main issue I have with your approach is that I feel like it creates too many headaches down the line because you somehow must exclude that load from the rest of the analysis. This becomes even more troublesome when interacting with RAM Connection and Concept. The solution for me was to simply print the beam loading from RAM Beam, multiply all the dead loads by 0.2, and check it in a standalone program.
Another option (for beams that are lateral) would be to use a custom combo with something like " -0.2D " as the load factor (negative terms are allowed), if that makes it any easier.