Caisson footing on a hillside

Can you can confirm the general rule of thumb for hillside drilling of caisson type footings.
It’s approximately a 1:2 incline.
10’ out I’m reading 6’ of fall. The caissons would need to be twice that or 12’ minimum.
It’s not a permitted job. I’m underpinning an existing slab walkway to stabilize it.


Any photos? If I understand your situation correctly you have a sidewalk poured at the edge of a steep embankment, which has settled or moved. Your plan is to drill down and pour concrete caissons to support the sidewalk. Are you raising the slab first, i.e. mud jacking or just trying to stop further settlement?

Randy the objective was to stabilize things. I caught your earlier post.
We ended up korbling beneath the slab and tying the steel beneath and in the stem wall into an 18" diameter piling. One of them went to 15’ as I was hoping to get into bedrock at least 2’. Grouted the transition crack yesterday so we shall see if things are going to hold up!