Some time ago I was responsible for a geotechnical report about a retaining wall in a lagoon. I only had a field of measures made up of: 6 CPTUs, 1 DTM and 3 soil samples. Hey a large amount of data! In that occasion I used a commercial software and a spreadsheet application, because the time was too little and I had not discovered IPython notebook yet. I show you through a short screencast how it is powerful and easy to use, perfect to this type of analysis.
In my opinion SSAP2010 is an interesting freeware to verify slope stability and despite of other commercial softwares, it considers some inhomogeneities for example: soils, groundwater at different levels, different surfaces and stability elements (wall, sheet pile, etc.).
Some time ago I had to verify in a short time, different hypothesis for a sheet pile wall installation in a layered soil: fixing length and distance of the anchor from the surface. I have modified a BASIC program found in the Web, adapting it to my needs.