Redudancy Factor and SLRS foundations

[LL805]

As a designer, I have always applied rho =1.3 (redundancy factor) when required for the building per ASCE 7-10 12.3.4 to the SLRS foundation design. The foundation design would include both the SLRS foundation itself as well as the soil bearing pressure check. ASCE7-10 12.3.4.1 does not explicitly note foundations as an exception where rho = 1.0 and the ASD load combinations under 12.4.2.3 include rho. I've now been engaged with some other engineers who only apply rho to the foundation design but not the soil bearing pressure check. The argument is that the soil is not part of the SLRS and therefore rho should not be included; ASCE7-10 states that rho is only to be applied to the SLRS system. My counter to this is that the definition to the SLRS system is "that part of the structural system that has been considered in the design to provide the required resistance to the prescribed seismic forces"; the soil resists seismic forces and therefore is part of the SLRS system. In this specific case, the soil bearing pressure has already been doubled for short-term loading.

The more engineers I talk to, the more opinions I get. It seems that more seasoned engineers (10+ years experience) don't think rho should be applied to soils while younger engineers tend to think the code is clear and that you should be applying it. Other articles I've found indicate that it should be applied to "foundations" but do not make a clear distinction between design and soil bearing.

I did a search on this site but didn't find anything on it. If this has been discussed previously, please include the link!

Thanks!