I realized that due to the many contact areas in my assembly, I need to run a nonlinear analysis instead of a static analysis. Unfortunately, the virtual wall feature is not available for Nonlinear Studies (although the foundation bolt is available, even though it needs a virtual wall to go with...)  Are there any solutions for this, short of adding the actual mounting ledge into the model?

I attached a pic for reference. The wall would have supported the selected surface.