Retaining wall factors of safety

[Kramer]

A question for the geotechnicals:
As a structural engineer, I typically design retaining walls with a 1.5 factor of safety for sliding. When allowable friction and allowable passive pressure values are given in a soils report, do these already have a safety factor built in (as in allowable stresses), or are they ultimate values? I want to know if I have been doubling up on the safety factor!

 

[Ginger]

Generally, the term permissible means that the FoS (whatever it is) will already be included. Andy Machon