Fixed Base Plate in SDC C

[Rdar43]

I'm working on a 3 story steel framed project and received a geotech report indicating site class E which is now bringing the seismic design category up to C. Most of the projects I've worked on are typically low seismic and I haven't had to design a building past SDC B. I've read through ASCE, ACI, and starting to go through AISC to get a general understanding of the additional checks that are required. The original plan for the lateral system before knowing the building fell under SDC C was going to use steel moment frames with fixed base plates and seismic system H, Steel Systems not specifically detailed for seismic resistance.

My questions for everyone are:
1) Is seismic system H still recommended when making the jump to SDC C or should I start looking towards other detailed system? Are there any general rule of thumbs when this change should be considered?
2) With the ACI requirements, it initially seems like getting fixed base plates will be very difficult to get to work. Does anyone know of a good reference, example problems, or webinar that covers all of the checks required when using SDC C or higher?

Additional Project Info:
- Risk Category 3
- S1 = 0.057, Ss = 0.271, Fa = 2.341, Fv = 4.2
- Worst case frame is occuring above a 2 story ball room and the 3rd story is in a different portion of the building. Frame height = 23ft and span = 48ft
- Preliminary BP reactions [LRFD] and size, Mx = 185k*ft, Vy = 14k, N = 90k (Compression), Vx = 4.5k , My = 49k*ft, Column = HSS10x10x3/4


If there's any additional info needed let me know and I'll try and provide it.

 

[phamENG]

System H is permitted in SDC C, so you should still be okay there. Other methods may reduce member sizes but at the cost of more complex/stronger connections. If you're in an area with fabricators and erectors who are not familiar with such requirements, probably just better to let the whole thing be a little beefier with "normal" connection detailing.

No chance of using braced frames that let you drop to pinned base connections?