AISC 341-10 on SCCS is only 2 pages and doesn't limit angle and I'm fairly confident ASCE 7-10 doesn't limit it either. I suspect this is entirely a practical limit where your flexural demand is going to be ridiculously large.
Also, remember that the code isn't meant to cover every situation (despite their best efforts and the increasing complexity). Your engineering judgement can and should be something to rely on in these situations.
Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries
As long as modelling reflects reality, this might actually be better than a vertical SCC system. Taken to the extreme, the columns become horizontal, cantilever beams with no P-delta problems at all.
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.
KootK may be on to something. One big issue with the seismic performance of the SCCS is that the system relies on the anchorage at the base for all lateral resistance and it's difficult to impossible to realistically get this out of typical concrete anchorages. However, your large angle means you may reduce or eliminate much of the oscelations in the anchorage and go towards just a variation of tension in the anchors as the column sways. Obviously still has all the issues of a typical SCCS but I agree with KootK that it shouldn't be any worse than typical.
Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries
