Step Down foundation sample

[Hammer7]

Foundation step downs.  Is there a sample of where to do this according to a site TOPO?  Short segments vs. Long segments?  How is this typically illustrated in plan view?

 

[rlackore]

Short or long depends on the site characteristics. My general rule of thumb is to try and keep segments a minimum of 5'-0" long, and to drop no more than 24" per step. These rules aren't always achievable, or desirable. I can't remember if there is a rational engineering basis for these rules. It's important to provide adequate horizontal reinforcement at the drops to help prevent cracking at the reentrant  corner formed at the drop. Here's how I annotate these conditions in Chief:

 

[rlackore]

Digging through all my old references, I've found a few that advise that the horizontal length of the footing should not be less than 2 feet. So, length should be no less than 2 feet, and drop should be no greater than 2 feet. Unless engineered, of course. I advise using a haunch in the footing at the step.