This current tool implements the modified Casagrande Plasticity Chart (1948), including the A-line, to classify fine-grained soils based on their plasticity characteristics as expressed by the Plasticity Index (IP) and Liquid Limit (LL).

This tool derives soil stratigraphy from CPT or CPTU data using both non-normalized (pre-1990) and normalized Soil Behavior Type (SBT) indices proposed by Robertson. By interpreting cone resistance, sleeve friction, and pore pressure data (where available), the tool identifies changes in soil behavior with depth.

The method offers a data-driven approach to interpreting subsurface layering and can complement borehole investigations, particularly in sites with limited sampling or where continuous profiling is beneficial.