Dear FAF, if you are looking for geotechnical design software, you should look at the products of FINE
http://www.fine.cz/ or Plaxis and similar. ATENA has no direct support for the concepts of active and passive earth pressure, but it can be (and frequently is) used for nonlinear analysis of structures including rock and soils, like tunnels, foundations, or underground tanks. Simply said, you can either model a small part and apply the "far field" pressure as a load, or include the overburden in your model and apply its dead weigth (of course, the boudary conditions frequently need special attention).