friction pile versus belled caissoon design 1

[Barbaneagra]

When calculating the embedment of friction piles one uses, vertical load, seismic load and creep. For iisolated pad footings we don't. If I'm designing a hand dug caisson (end bearing deep foundation) should I still include creep and seismic ? At which point a footing becomes a caisson (from a regular pad footing) , what depth is considered a turning point, 3'... 5'... 7' ?

 

[JAE]

Why wouldn't you include seismic in every footing? I'm not sure what you mean by isolated pad footings not being designed for seismic load. All elements of a structure should be designed for all required load cases and combinations.