Saital
  I have not use SAFE before.  But I have used STAAD to model a pile analysis.  I simply model the pile into several elements with spring constant as spupports and model a vertical support at bottom, but free at top.  The spring constant can be derived by using some parameters provided by the Geotechnical Engr.  Please refer to the book by Bowles, "Foundation Anlaysis and Design".  It tells you the methods to derive the stiffness of the soil.

For modeling piles, I would use STAAD and not SAFE. SAFE is for slab analysis. Check out http://www.reiworld.com/Search.asp?id=SP-119 for an example on how to do it.

A more direct method to model piles for the effects of lateral load and include soil structure interaction is to use a program called LPile, used by just about every Geotech that I know.  This program utilizes input soil parameters, boundary conditions of the pile (fixed or free at the head of the pile in the cap) and calculates effective soil springs based on depth and material properties.  The output will include displacement, shear and bending moment plots along the depth of the pile.