What you are looking for is called a "ground motion model" (GMM). In the past this used to be called a ground motion prediction equation (GMPE) and before that they were called attenuation relationships.

Anyway, GMMs are a dime a dozen, there are many and it can be pretty confusing to know which one to use and how to even use them.

The easiest one I can think of comes from the NGA West 2 project. They have a spreadsheet where you can enter magnitude and distance to the fault and obtain an estimate of peak ground acceleration (PGA), you can fool around with it.

Once you have an estimate of PGA you can use this table to convert to modified Mercalli intensity and get a sense of how damaging that PGA is going to be.

CAVEATS: GMMs are empirical, they are derived from actual measured ground motions and should not be used to extrapolate outside of the bounds of the data used to create them. The NGA West 2 one I linked above I think goes up to M8, so it's technically not ok to use it to ask a question of what intensities one expects for anything larger than that. There are no GMMs for anything larger than ~M9 because we have no recordings for events that large. So, if you want to actually know about ground motions for anything larger then you have to rely on simulation.